C-125, C-145 and O-300 Series Engine Overhaul Manual

Transcription

C-125
C-145
O-300
CONTINENTAL® AIRCRAFT ENGINE
OVERHAUL
MANUAL
FAA APPROVED
Publication X30013
©
2011 CONTINENTAL MOTORS, INC.
AUG 2011
Supersedure Notice
This manual revision replaces the front cover and list of effective pages for Publication Part No. X30013, dated
Basic Date. Previous editions are obsolete upon release of this manual.
Effective Changes for this Manual
0 .................... June 1982
1 ............ 31 August 2011
List of Effective Pages
Document Title: C-125, C-145 & O-300 Series Engines Overhaul Manual
Publication Number: X30013
Page
Change
Page
Change
Page
Initial Publication Date: June 1982
Change
Page
Change
Cover............................ 1
A................................... 1
B - blank added ............ 1
ii thru iv......................... 0
1 thru 61 ....................... 0
Published and printed in the U.S.A. by Continental Motors, Inc.
Available exclusively from the publisher: P.O. Box 90, Mobile, AL 36601
Copyright © 2011 Continental Motors, Inc. All rights reserved. This material may not be reprinted, republished, broadcast, or otherwise
altered without the publisher's written permission. This manual is provided without express, statutory, or implied warranties. The publisher will
not be held liable for any damages caused by or alleged to be caused by use, misuse, abuse, or misinterpretation of the contents. Content is
subject to change without notice. Other products and companies mentioned herein may be trademarks of the respective owners.
A
C-125, C-145 & O-300 Series Engines Overhaul Manual
31 August 2011
Intentionally Left Blank
INTRODUCTION
This revised edition of the Maintenance and Overhaul Instructions includes the
descriptive material and instructions contained in previous editions. In addition,
information regarding new models 0-300-C and 0-300-D has been added, making
these instructions applicable to the 6 cylinder models in the "C" series which
are in service and in production. A parts list is contained in a separate Parts
Catalog, Form No. X-30014.
Due to the similarity of the C145 and the 0-300 model engines, all references
and instructions regarding the C145 engines shall apply to 0-300 engines, unless
otherwise indicated, throughout this manual.
This manual is intended primarily for the mechanic who is engaged in the maintenance and overhaul of models C125, C145, 0-300-A, 0-300-B, 0-300-C,
0-300-D and 0-300-E engines. Operating instructions contained herein are intended for those who operate and test these models in connection with maintenance
work. Descriptive text in Section 3 covers all models, as currently designed
and built. Service instructions in Sections 7, 8 and 9 constitute the necessary
preventive and minor corrective maintenance procedures. These measures, if
followed, will assure continued reliability of engines during the period between
overhauls. These and the overhaul instructions in Sections 10, 11 and 12 are
intended to cover adequately the work involved. If additional information is required an inquiry should be addressed to the nearest Continental Service Station.
The significant differences between the 0-300 models are as follows:
A. The 0-300-A engine has a SAE No. 3 flanged propeller shaft and provisions
for a starter, generator, voltage regulator and fuel pump.
B. The 0-300-B engine is identical to the 0-300-A except for provisions for use
of a manually controlled hydraulic propeller.
C. The 0-300-C engine is identical to the 0-300-A except for ARP 502 Type I
flanged propeller shaft and Slick Electro Inc., Magnetos. Information regarding
maintenance, overhaul or adjustment of these magnetos may be obtained from
Slick Magneto Inc. , Rockford, Illinois. All 0-300-C engines subsequent to serial
No. 21001 are so equipped that a right angle starter drive can be used if desired.
D. The 0-300-D engine is identical to the 0-300-C except that the starter is
mounted on an adapter which provides a right angle drive.
E. The 0-300-E engine is similar to the 0-300-D except for incorporation of
governor drive pad and crankshaft provisions to supply governor oil to the propeller.
F. An alternator is available as optional eqUipment on the 0-300-C, D and E
engines. Service information on the alternator may be obtained from General
Parts Division, Ford Motor Co., P. O. Box 412, Ypsilante, Michigan.
ii
TABLE OF CONTENTS
Section 1 - Table of Specifications. •
Section 2 - General Description. •
1. Difference in Engine Models.
2. Cylinder Construction
3. Piston and Piston Pin Construction.
4. Connecting Rods • , . . • , • • •
5. Crankshaft Construction. . . • . •
6. Crankcase and Oil Sump Construction.
7. Crankcase Cover. • • • . .
8. Valve Operating Mechanism.
9. Lubrication System. . . . .
Page
4
6
6
6
6
7
7
7
7
7
8
Section 8 - Service Inspection and Associated
Maintenance. • • . . .
1. Daily Inspection • • • • • • • • •
2. 100-Hour Inspection • • • . . • •
3. Major Overhaul or Remanufacture • •
Section 9 - Adjustment, Replacement and
Minor Repair • • . • . • • . • . • •
1. Carburetor • • • • • • • • • • •
2. Magneto Installation and Timing to the
Engine • • •
3. Ignition Wiring.
4. Starter . .
5. Generator. • •
OPERATING AND MAINTENANCE
INSTRUCTIONS
Page
17
17
17
18
18
18
18
18
18
19
OVERHAUL INSTRUCTIONS
Section 3 - Introduction. • ••
••••••
Section 4 - Packing, Unpacking and Preparation
storage • • • • • • • •
1. Shipping Boxes •
•••••••
2. Packing..
•
•
•
•••
3. Unpacking the Engine.
••••
4. Preparation of Engine for storage
5. Preparation of Engines for Service After
storage . • • • • • • • • • • • ••
Section 5 - Installation in Airplane and Removal
1. Engine Mounting • • • • • • •
2. Fuel and Carburetor System. • • •
3. Oil System.
•
••••••••
4. Engine Removal • • • • • • • • •
Section 6 - General Operating Instructions
1. Before starting.
• • •
2. Starting. • • • • • • •
3. Warm-Up and Ground Test
4. Take- Off and Climb.
5, Cruising. • ••
•••
• • ••
6. Landing. • • • • • • •
7. Stopping the Engine. • •
8. Carburetor Heat Control
• • ••
Section 7 - Engine Troubles and Service Repairs
1. Failure of Engine to Start •
••••
2. Low Oil Pressure • • •
3. High Oil Temperature. • •
4. Low Power • • • • • • •
5. Rough Running. • • • • •
6. Engine Fails to Accelerate Properly
10
10
10
10
10
11
11
11
11
11
11
15
15
15
15
15
15
15
16
16
16
16
16
16
17
17
17
17
Section 10 - Disassembly, Cleaning and
Inspection • • • • . • • •
1. General. ••
••••
2. Preliminary Operations.
3. Disassembly. • • •
••
4. Cleaning.
5. Inspection. • . • • .
Section 11 - Repair and Replacement.
1. General Repair. • • •
••
2. Castings. ••
••••.••
3. Stud Replacement. • • • • • •
4. Helical Coil Insert Installation. •
7. Parts to be Discarded..
•
8. Repair and Replacement of Engine Parts
Section 12 - Reassembly, Final Assembly,
Timing and Testing • • • • • • • • •
1. Reassembly of Major Subassemblies
2. Final Assembly Procedure.
••
3. Engine Run-In and Test Procedure
After Major or Top Overhaul •
Section 13 - Table of Limits • • • • • •
Section
Section
Section
Section
Section
Section
Section
14
15
16
17
18
19
20
-
ACCESSORIES
Marvel-Schebler Carburetor.
Bendix S6LN-21 Magnetos
Hydraulic Tappets • • • . •
Delco-Remy Starter • • • •
Delco-Remy Generator • • •
Delco-Remy Generator Regulators
Right Angle Starter Drive Adapter
20
20
20
20
22
22
25
25
25
25
25
26
26
29
29
30
34
39
45
49
50
52
54
55
57
LIST OF TABLES
TABLE
TABLE
TABLE
TABLE
TABLE
TABLE
TABLE
TABLE
TABLE
TABLE
TABLE
TABLE
TABLE
TABLE
TABLE
TABLE
I
II
m
IV
V
VI
VII
vm
IX
X
XI
XII
xm
XIV
XV
XVI
Characteristics and DimenSions
Purchased Accessories
Ignition System • • • • •
Fuel System • • • • • •
Lubrication System • • •
Accessories and Weights
Oil Viscosity Grades
Temperature Limits. • •
Table of Dimensions. • •
Magnaflux Inspection Data
Standard and Oversize Stud Identification
Test Operating Limits. •
Standard Acceptance Test •
Deleted • • • • • • • • .
Deleted • • • • • • . • •
Magnaflux Inspection Chart
Page
4
4
4
5
5
5
5
5
23
24
26
35
36
59
INDEX OF ILLUSTRATIONS
Fig.
No.
I.
2.
3.
4.
5.
6.
7.
8.
9.
10.
II.
12.
13.
14.
15.
16.
17.
18.
19.
20.
2l.
22.
23.
24.
25.
26.
27.
28.
29.
30.
3l.
32.
33.
34.
35.
36.
37.
38.
39.
40.
iv
Page
Three-Quarter Left Front View - 0-300
Right Rear View - 0-300-C .
.•
Right Rear View - 0-300-D. ••
•
Section Through Hydraulic Tappets.
Cutaway View Showing Gear Train •
Typical Installation Diagram
Installation Drawing • • • • • • •
Ignition Wiring Diagram for Bendix
SF6LN-12 Magnetos • • • • • . •
Ignition Wiring Diagram for Bendix
S6LN-21 Magnetos. •.
• •••
Ignition Wiring Diagram for Slick 664 Magneto
Starter. . . . . . . .
....
....
Compressing Valve Spring for Installation
and Removal of Locks ••
•
Removal of Hydraulic Unit From Cam
Follower Body.
••••••
•
Assembling No. 1 Connecting Rod • •
Assembling Rocker Shaft Bushings. • •
Measurement of Dampener Bushings •
Installing Cam Follower Body in Crankcase.
Installing Crankshaft Thrust Washer •
•.
Installation of Starter Pinion Pivot. ••
••
Installation of Crankshaft and Connecting Rods
Installation of Crankcase 1-3-5 Over Crankcase 2-4-6 • • • • • • • • • • • • • • •
Installation of Gears in Crankcase. • • • • •
Installation of Crankcase Cover to Crankcase •
Installing Cylinder on Crankcase • • • • • •
Lubrication Chart, Lateral Section Front View
Lubrication Chart, Longitudinal Section View.
Lubrication Chart, Accessory Cover Section •
Carburetor Right Side View. • • • • • • • •
Carburetor Left Side View • • • • • • • • •
Cutaway Views of Marvel-Schebler MA-3SPA
Carburetor • • • • • •
Starter. • • • • • • • •
Typical Wiring Diagram • • •
Generator • • • • • • • • • •
Current and Voltage Regulator.
Starter and Adapter • • •
Needle Bearing Installer •
Installing Needle Bearing. •
Table of Limits Chart • •
1
2
3
8
9
12
12
13
14
18
19
19
19
21
21
22
27
27
30
30
31
31
•
•
32
33
•
33
34
42
43
•
•
45
45
44
46
52
52
54
56
58
59
59
61
1
2
3
Section 1
TABLE OF SPECIFICATIONS
TABLE 1
Dimension
CHARACTERISTICS AND DIM:ENSIONS
Model
All
All
All
C125
C145, 0-300-A, B, C, D & E
C125
C145, 0-300-A, B, C, D & E
C125
C145, 0-300-A, B, C, D & E
C125
C145~ 0-300-A, B & C
0-300-D & E
All
C125, C145, 0-300-A, B & C
0-300-D & E
All
C125
C145, 0-300-A, B, C, D & E
C125
C145, 0-300-A, B, C, D & E
C125
C145, 0-300-A, B, C & D
Piston strokes per cycle
Number of cylinders
Cylinder bore (in.)
Piston stroke (in.)
Compression ratio
Total displacement (cu. in. )
Overall length (in.)
Overall width (in.)
Overall height (in.)
Number of mounting brackets
Rated RPM
Rated B. H. P.
Total dry weight (lbs.)
TABLE II
Model
C125, C145
U-300-A, B
Accessory
Magneto
Value
4
6
4-1/16
3-5/8
3-7/8
6.3:1
7.0:1
282
301
41-9/16
35-15/32
35-17/32
31-1/2
27-13/32
26-29/32
4
2550
2700
125
145
257
268
PURCHASED ACCESSORIES
Manufacturer
Accessory Model
or Part Number
Bendix Magneto Division
Bendix Aviation Corporation
S6LN-21
Quantity
2
Slick Electro Inc.
664
2
Delco-Remy Division
General Motors Corporation
1109656
1
0-300-D, E
Delco- Remy Division
1109694
1
C125, C145
Generator
0-300-A, B, C & D
Delco- Remy Division
1101890
1
0-300-E
Generator
Delco-Remy Division
1101898
1
0-300-C, D & E
Alternator(Opt. )
General Parts Division
Ford Motor Company
CGFF-10300-C
1
All
Carburetor
Marvel-Schebler Division
Borg- Warner Corporation
MA-3-SPA
1
0-300-C, D, & E
C125, C145
0-300-A, B& C
Starter
TABLE III
Feature
Left magneto fires lower plugs
Right magneto fires upper plugs
Firing Order
Spark plug gap setting
Permissible RPM drop when switched from
"both" to either "left" or "right" magneto
4
IGNITION SYSTEM
Model
C125
C145, 0-300-A, B, C, D & E
C125
C145, 0-300-A, B, C, D & E
All
All
All
Value
30 0 B. T. C.
28°B. T. C.
28°B. T. C.
26°B. T. C.
1-6-3-2-5-4
0.015 - 0.021
75 RPM
TABLE OF SPECIFICATIONS (Cont.)
TABLE IV.
FUEL SYSTEM
Feature
Model
Minimum fuel octane rating
All
Fuel inlet to carburetor (NPT')
Venturi diameter
Fuel consumption (cruising, approx)
(Gal/Hr)
All
All
C125
C145
0-300-A, B, CJ D & E
TABLE V.
Feature
Oil sump capacity
Minimum oil supply at any time
Oil consumption
Oil pressure (psi)
Idling
All
All
All
C125
C145, 0-300-A, B, C, D & E
C125
C145, 0-300-A, B, C
0-300-D & E
All
Cruising
Oil temperature (Min. Take- Off)
TABLE Vi
Accessory
LUBRICATION SYSTEM
Model
ACCESSORIES AND WEIGHTS
Model
Carburetor
Magnetos (2) (with gear)
All
C125
C145, 0-300-A & B
0-300-C, D & E
All
All
All
C125, C145, 0-300-A, B, C, D
0-300-E
0-300-C, D, & E
C125, C145, 0-300-A, B & C
0-300-D, E
All
Spark plugs (12)
Radio shielded ignition cables
Fuel pump
Generator
Generator
Alternator (Opt. )
Starter
Carburetor air intake & filter
Value
80187
1/4-18 NPT
1-5/8 in.
8.5
9.27
12.5
Value
8
4
0.017#/BHP/hr
10
5
30 - 40
30 - 45
30 - 60
75°F
Weights
3.0 lbs.
18.0 lbs.
11. 56 lbs.
12.70 lbs.
2.54 lbs.
4.9 lbs.
1. 9 lbs.
10.21 lbs.
16. 21 lbs.
10.81 lbs.
15.5 lbs.
13.5 lbs.
3.5 lbs.
TABLE VIi OIL VISCOSITY GRADES
Ambient Air temperature
SAE Grade
SAE No. 20
Below 40° F.
SAE No. 40
Above 40° F.
When operating oil temperatures overlap above column ranges, use the lighter oil.
It is recpmmended that oil be changed every 20 to 30 hours,
The use of Multi Viscosity oil is approved. See latest fuels and lubricants bulletin for list of approved oils.
TABLE VIIi
TEMPERATURE LIMITS
Feature
Model
Maximum oil temperature (OF)
C125
C145, 0-300-A, B, C, D & E
C125
C145, 0-300-A, B, C, D & E
220
225
550
525
C125
C145, 0-300-A, B, C, D & E
300
290
Maximum cylinder head temp (OF)
(Measured by thermocouple imbedded in
down-stream spark plug gasket)
Maximum cylinder base temp (OF)
(Measured by cylinder barrel contact
thermocouple)
Value
5
Section 2
GENERAL DESCRIPTION
1. DIFFERENCES IN ENGINE MODELS
a. General. The higher power developed by C-145
engines is the result of a combination of a longer piston stroke and a higher rated crankshaft speed. The
longer stroke produces a higher compression ratio,
making necessary the use of fuel of a higher octane
rating, and a larger total piston displacement, which
increases total fuel consumption. Specific fuel consumption of both models is approximately. 5 lbs. per
brake horsepower per hour at cruising speed and
manifold pressure. Model C-145 has a slightly lower
specific fuel consumption at its most efficient operating speed. These differences in dimensions require
different carburetor metering parts.
b. Pistons. All three compression rings are the
same type in the two types of piston assembly and are
fitted in grooves above the piston pin. The slotted oil
control ring in the C-125 piston assembly is also
above the pin - in the fourth groove, while the similar
oil control ring in the C-145 piston assembly is placed
in a groove near the bottom of the skirt and is dimenSionally slightly different. Connecting rod space between piston pin bosses in the C-145 piston is narrower than in the C-125 piston. All piston pins currently
produced have pressed-in aluminum end plugs to prevent excessive plug rotation and wear. This type of
pin assembly must be used in all C-145 engines;
however, the former type of pin assembly with loose
end plugs may be used in C-125 pistons as long as
parts are serviceable or repairable by replacement
of plugs.
c. Connecting Rods. C-145 connecting rods have
shorter piston pin bosses and bushings than those of
model C-125. Crankpin bearing inserts installed in
early production C-145 connecting rods were TriMetal bronze. These have been superseded by the
same type of bearing used in C-125 connecting rods.
d. Crankshafts. C-145 crankshafts have a slightly
longer crank throw than those of model C-125. (Refer
to Section 1 for dimensions. ) Early production C-145
crankshafts had no counterweights and were identified
by a 1/4 in. diameter hole drilled between propeller
bolt bushings through the propeller flange. Current
production C-145 crankshafts have two floating counterweights loosely pinned to extensions each Side of
the cheek between No's it and 2 craukpi..o.s. 'The natural .frequency of oscillation of the weight on the
notched crankshaft extension is adjusted, by size of
its bushings, to dampen out the fifth overtone of crankvibration, while the other counterweight dampens t"~
sixth overtone, preventing excessive vibration of the
crankshaft gear and wear of gear teeth. C-125 crankshafts do not have or require the dynamic damper
weights. Crankshafts of model C-145-2H have an oil
inlet hole through the front main journal, whose hollow
interior has a permanent plug at the rear and a removable plug at the front, providing an oil passage to
the shaft end for hydraulic actuation of the controllable
propeller. The letter "D" in a C-145 serial No. denotes a dampened shaft, ,
6
e. Camshafts and Valve Lifters. All C-125 engines
are equipped with cast iron camshafts and steel faced
valve lifters. Earlyproduction C-145 engines had the
same type of lifters and cast iron camshafts of special
design. Current production C-145 engines have forged
steel camshafts and valve lifters whose bodies are
single piece iron castings. The forged steel camshafts
are copper plated, between lobes and journals, on the
unfinished surfaces, and the entire surface is ParkoLubrite coated for protection until the shafts are installed. This is a soft, black coating which rubs off
easily if the parts are carelessly handled. It is essential that the proper type of valve lifter bodies be
installed with each type of camshaft. It is recommended that forged steel camshafts and cast iron lifter
bodies be installed in all C-145 engines - not already
so equipped - at the next major overhaul.
f. Crankcases. Engines have crankcases in which
the two shorter through studs and seven of the longer
ones are replaced by headless through bolts which also
act as dowels to align the halves. Two long and one
short dowel bolts used in parting flange holes of the
old type case are not installed in the current type.
The new type cases may be installed in any C-125-2
engine or in any C-145-2 engine. All C-145-2H engines have crankcases of the new type, but these have
a special valve near the front end of the left oil gallery
to control oil flow to the special crankshaft passage.
g. Oil Sumps. The sump assemblies installed in
C-145 engines have baffles in the intake air passages.
The baffle is not used in C-125 sumps.
2.
CYLINDER CONSTRUCTION
Heat-treated aluminum alloy cylinder heads are
screwed and shrunk to replaceable forged steel barrels. Closely spaced cooling fins on both the cylinder
heads and cylinder barrels provide am:ple heat-dissipating surface with minimum resistance to air flow.
Cylinder bores are ground to a certain finish specified
in the Table of Limits, Section 13. Stainless steel
helical-coil spark plug inserts are screwed in place.
Rocker boxes are cast integral with cylinder heads and
are provided with lightweight covers made of deep
drawn sheet metal. Underside exhaust ports permit
a more compact installation and a more positive exhaust scavenging.
3. PISTON AND PISTON PIN CONSTRUCTION
a. Pistons are heat-treated aluminum alloy castings.
The ring grooves are fitted with chrome faced top
compression rings, plain cast iron 2nd. and 3rd. compression rings and slotted bottom oil control rings.
Holes drain oil from the bottom ring groove to the
interior.
b. The full-floating piston pin is a case-hardened,
seamless alloy steel tube with aluminum plugs
pressed into its ends. The plugs are finish machined
after assembly, and the pin is ground to final size and
pOlished.
4.
CONNECTING RODS
Connecting rods are of conventional split bearing
design and of heat-treated alloy steel forgings. The
split crankpin "big" end is fitted with two semiCircular, special alloy, precision bearing inserts. A
bronze bushing is pressed into the "small end" piston
pin boss. In current production rods a split, onepiece bushing replaces the former solid type. The
big end bearing cap has a squirt hole from which oil
sprays into the opposite cylinder. Connecting rods
are selected sothat the variation in weight within any
engine is not over 1/4 ounce.
5. CRANKSHAFT CONSTRUCTION
The alloy steel, one piece, six-throw crankshaft
is supported by four main bearings with semi - circular
steel backed precision inserts which are easily replaced. The crankshaft is drilled for lightness and to
provide pressure lubrication to crankpins. The crankshaft end clearance is maintained by split bronze
thrust washers at each end of the front main bearing.
The rear washer, between the front crankcheek and
the bearing, takes forward thrust. Rearward thrust
is taken by the front washer from a flange on the shaft
which also acts as an oil slinger. C-145 and 0-300
crankshafts have a blade extending from each side of
the cheek between NoT s 1 and 2 crankpins for attachment of dynamiC damper counterweights. Each blade
has two holes bored through and steel bushed. Slotted
counterweights fit over the blades and have holes bored
through and bushed to match those of the shaft. Bushings are sized to produce the desired frequency. Pins
are hardened and are retained endwise by steel plates
and Tru-Arc snap rings. A notched blade and a pin
in the 5th order weight assure correct installation.
6. CRANKCASE AND OIL SUMP CONSTRUCTION
a. The crankcase is a two-piece heat-treatedaluminum alloy casting, bolted together at the vertical
lengthWise plane through the crank and camshaft supports. Rigid transverse webs hold the four main
crankshaft bearings and the four camshaft journals.
A specially designed oil seal prevents oil leakage at
the nose end of the crankcase. Large lifter guides
are formed in the crankcase in a plane below and
parallel to the cylinders. Oil galleries molded in the
castings provide pressure lubrication to the lifter
guides, camshaft and main bearings. Circumferential
stiffening ribs under the cylinder pads give additional
strength and stiffness to the cylinder bosses. One cast
aluminum alloy mounting bracket on each Side of the
case near the front and one on each side at the rear
provide four engine mount paints, in all. Opposite
brackets are joined by through bolts, and each is also
attached to the case by two studs. A Lord bUShing,
clamped in each bracket, admits a 7/16 in. mount
bolt. Spreading of current production crankcase
halves is prevented by nine headless through bolts
located in the upper and lower sections of the crankshaft bearing bosses, and four headless through bolts
located in the lower part of the camshaft bearing
bosses. Hydraulic "0" rings installed in grooves of
tie bolts and the through stud near the case split prevent oil leakage to the bolt ends.
b. The oil sump is an aluminum alloy casting which
forms a trough beneath the open bottom of the crankcase. It is closed at the front end and open at the
rear. The sump is attached by crankcase studs and
sealed by a thick, reinforced gasket. Drain plugs are
installed in front of and behind the carburetor mount
pad in the sump floor. From the carburetor pad the
intake air passage extends upward through the sump
and branches to each side in a tee, ending at the intake manifold mount flanges at the sides of the sump
casting. Manifold flange screw holes and screw holes
in the rear surface for crankcase cover attaching
screws have helical-coil thread inserts. The sump
capacityis 8 U. S. quarts. The oil gauge rod, extends
through a guide pressed into a hole in the crankcase
left side and into the sump. A grooved shoulder on
the gauge carries a hydraulic "0" ring to prevent oil
splashing out along the rod. A clip type lock ring fits
on the guide and retains the oil rod in place securely.
7. CRANKCASE COVER
The magnesium alloy crankcase cover casting at
the rear of the engine houses the oil pump, suction
and pressure oil screens pressure relief valve and all
gears. Both oil screens are at the bottom of the
cover. The relief valve is at the right Side, and the
oil filler neck is pressed into a boss at the upper left
side. Studded mount pads are provided on the cover
rear surface for two magnetos, the starter, generator
and tachometer drive housing. The crankcase cover
extends over the rear end of the oil sump. It is attachedtothe sump by five screws and to the crankcase
by six studs, with a gasket in the jOint. The passage
from the pressure oil screen outlet is cored at the
rear of the sump, ending at the upper left rear corner,
where a crankcase hole into the left oil gallery registers with it.
8. VALVE OPERATING MECHANISM
a. General. Zero lash hydraulic tappets fit aluminum alloy guides machined in the crankcase and so
sealed as to positively prevent oil leakage. Tappets
are drilled in such a manner that an oil passage is
provided from the tappets to the push rods, which are
made of light steel tubing with pressed-in ball ends,
drilled, hardened and ground. This provides an oil
passage the entire length of push rod to rocker arm
bearings where the oil under pressure lubricates
valve stems and guides. The rocker acts directly on
the valve stem through a specially designed "foot" so
constructed as to prevent side-thrust on the valve
stem. Aluminum bronze intake valve seats, and
corrosion-resistant stainless steel exhaust seats,
provide maximum service life. Scavenging of oil
from the rocker boxes is by gravity through the push
rod housing tubes.
b. Hydraulic Valve Lifters. The lifters are composed of only four parts which can be disassembled;
the cup, cylinder, piston and cam follower body. The
piston and cylinder are not interchangeable. The
lifters are automatically adjusted to function properly
with valve lash ranging from . 030 inch to . 110 inch
between the valve stem end and rocker arm with the
lifter fully deflated. Oil lines to tappets operate on
full engine pressure and are located in such a way that
they register with lifter when valves are open. Oil
under pressure from the lubricating system of the
engine is supplied to the hydraulic lifter through hole
(H) to supply chamber (J). (See figure 4. )
With face of lifter on the base circle of the cam
and the engine valve seated as shown in figure 4, the
light plunger spring (K) lifts the hydraulic plunger (C)
so that its outer end contacts push rod, taking up the
clearance at this point and all along the valve train,
giving zero lash. As the plunger (C) moves outward,
7
increasing the volume in the pressure adjusting
chamber (L) the ball check valve (D) moves off its
seat and oil from the supply chamber (J) flows in and
fills chamber (L).
As the camshaft rotates, the cam pushes the
lifter body outward, tending to decrease the volume of
chamber (L) and forcing the ball check onto its seat.
Further rotation of the camshaft moves the lifter
body (A) outward and the confined body of oil in
chamber (L) acts as a member in the valve operating
mechanism, the engine valve being lifted on a column
of oil. So long as the engine valve is off its seat, the
load is carried by this column of oil.
During the interval when the engine valve is off its
seat, a pre-determined slight leakage occurs between
plunger and cylinder bore, which is necessary to
compensate for any expansion or contraction occurring in the valve train. Immediately after the engine valve closes the amount of oil required to refill
the adjusting chamber (L) flows in from the supply
chamber (J) thus establishing the proper length of oil
column to maintain zero lash during the next cycle.
The basic principle of the hydraulic lifter is that
it provides, between the cam and the push rod, a
column of oil which carries the load, while the engine
valve is off its seat, and the length of which is automatically adjusted so that each camshaft cycle gives
zero lash.
9.
LUBRICATING SYSTEM
To reduce the number of external oil lines, an oil
sump is attached directly to the crankcase. Oil is
drawn from the oil sump through a suction screen in
the lower left corner of the crankcase cover and
through a cored passage to the oil pump. Oil is now
delivered under pressure to a second screen from
which it goes through drilled passages in the crankcase cover anp crankcase to all drive bearings,
through the crankshaft, to the crankpins. Engine oil
from the pressure pump is carried through drilled
passages in the crankcase to the hydraulic tappets.
After entering the tappets, it travels out through the
overhead mechanism through hollow push rods, and
drilled rocker arms where it is spilled over the valve
mechanism. As it drains away, it thoroughly oils the
valve stems and valve guides. The oil is returned to
the crankcase by way of the push rod housings, and
drains back into the oil sump through openings in the
crankcase. The cylinder walls and piston pins are
lubricated by spray. All excess oil is scavenged from
the crankcase and returned to the oil sump by gravity.
The pressure relief valve is set to give 30 to 60
pounds of pressure per square inch at speeds ranging
from 2100 to 2700 R. P. M. Refer to Section 13, Table
of Limits for charts showing the lubrication system.
Figure 4. Section Through Hydraulic Tappet.
8
3
Figure 5. Cutaway View Showing Gear Train.
GEAR TRAIN ANALYSIS
Figure 5 shows the complete gearing arrangement from the crankshaft
rear take-off to all accessories. The arrow on each gear indicated direction
of rotation as viewed from the rear of the engine, and the following analysis
describes each gear function with its speed in relation to the crankshaft.
(1) The crankshaft gear is attached by means of four cap screws to the
crankshaft gear mounting flange and rotates at crankshaft speed in a clockwise direction.
(2) The cam gear is driven by the crankshaft gear (1) at 1/2 crankshaft
speed.
(3) The right and left magneto drive gears, driven by the camshaft gear
(2), turn in a clockwise direction at 1. 50: 1 crankshaft speed.
(4) The oil pressure pump drive gear is driven by cam gear (2) through
a male-female square type coupling, and turns in a counterclockwise direction
at 1/2 crankshaft speed.
(5) The oil pressure pump driven gear is driven by gear (4) at 1/2
crankshaft speed in a clockwise direction.
(6) The generator gear is driven by the inner tooth track of the cam
gear (2) in a counterclockwise direction at 2.035:1 crankshaft sp~ed.
(7) The starter pinion engages with the crankshaft gear (1) and turns in
a counterclockwise direction at 5.111 times crankshaft speed.
9
Section 3
OPERATING AND MAINTENANCE
INSTRUCTIONS
INTRODUCTION
1. The following sections 4, 5, 6, 7, 8, and 9
constitute the instructions required for all unpacking,
installation, removal, test, operation, inspection and
minor repair of models C125, C145, C145-2H and
0-300 Series Continental aircraft engines. These
instructions do not need to be extensive, since the
engines require relatively little servicing between
overhauls, however, it is most important that they be
followed carefully and that all work be performed in
accordance with the best practices and with due attention to details in the interest of safety.
2. In this publication the following definitions will
be used:
(a) The propeller end of the engine will be referred
to as the "Front" of the engine, and the anti-propeller
end will be referre~d to as the "Rear." The terms
"Right" and "Left" are referred to as viewing the engine from the rear looking in the direction the propeller shaft pOints.
(b) Direction of rotation of the crankshaft is clockwise when lOOking from the rear toward the front of
the engine.
Cylinders are numbered as follows:
Cylinder No. 1 Right, rear of crankcase
Cylinder No. 2 Left, rear of crankcase
Cylinder No. 3 Right, center of crankcase
Cylinder No.4 Left, center of crankcase
Cylinder No. 5 Right, front of crankcase
Cylinder No.6 Left, front of crankcase
3. No special tools are required for inspection,
minor maintenance or accessory replacement, with
the exception of ignition timing indicators.
The
Time-Rite piston position indicator for ignition
timing is available from the manufacturer, Gabb
Manufacturing C~., 16 Orchard St., East Hartford,
Connecticut. Most tool manufacturers offer double
hexagon box end, socket and open end wrenches in
thin patterns suitable for all requirements of these
engines. It is advisable to use good quality tools and
to keep them dry and clean to avoid damage and
injury.
4. Engine parts and accessories required for maintenance work must be procured through Continental
Distributors and their dealers. Employees of these firms are
familiar with Continental parts and will gladly assist you in
any way possible. Any reconditioned parts, which have
been repaired, rebushed or reground at the factory have
passed rigid inspection. In this category are crankshafts,
connecting rods, cylinders, carburetors and magnetos.
5. All recognized methods of inspection and quality
control are employed in building these engines; however, if
any part should be suspected of failure, notify the nearest
Continental Representative at once, giving full
information, including the engine model and serial
numbers. Do not attempt repairs without factory
permission if an adjustment under our warranty is
expected.
Section 4
PACKING, UNPACKING AND PREPARATION
FOR STORAGE
1. SHIPPING BOXES.
The engines are packed for shipment in a wire
bound shipping box of the following general dimensions:
Overall length .••• 43-1/4 inches
Overall width••••• 33-1/2 inches
Overall height .•• 28-1/2 inches
Empty weight •••••...• 85 Ibs.
Gross weight ••••.••. 371 Ibs,
2. PACKING.
The engines are packed for shipment in their
standard wooden shipping boxes in normal operating
position and are fastened securely with four bolts
10
through the mounting bushings. The engine is·covered
with a prefabricated waterproof shroud. The lid of
the box is securely fastened to the lower section by
means of four steel hinges, the pins of which can be
driven out after removing the lock pins.
3. UNPACKING THE ENGINE.
(a) Drive out the four hinge pins, and remove the
lid.
(b) Remove the four nuts which hold engine mounts
to mounting base.
(c) Attach lifting sling to lifting eye which is bolted
to the upper crankcase flange above the center of
gravity. Remove 4 mounting bolts.
(d) Lift engine straight up. Remove shipping box
from beneath engine.
(e) Lower engine toa suitable assembly stand, and
bolt it securely.
4. PREPARATION OF ENGINE FOR STORAGE.
(a) Engines in crates and those installed in aircraft,
not to be operated for a period of more than seven
days should be prepared for storage as follows:
(1) Arrange a pressure tank and hose with wide
angle spray nozzle near the engine, and fill with a
suitable corrosion preventive oil. The oil mixture
should be a type which may be used as a lubricant and
which will leave no gum or other residue. Usually a
mixture of one part corrosion pre venti ve compound
and 3 parts S.A.E.#30 lubricating oil is satisfactory..
(2) Fill the oil sump with the same corrosion preventive mixture, after draining the regular oil.
(3) If the engine is installed, start it and warm up to
normal oil temperature.
(4) Stop the engine; remove the intake air filter, and
arrange the spray nozzle to spray the corrosion
preventive mixture into the air scoop.
(5) Start the engine and run at high idling speed with
the mixture spraying into the intake until a dense fog
emerges from the exhaust. Stop with the spray still
in operation.
(6) Remove the sump drain plug. After the sump
has drained, attach the plug with wire (not installed).
Post a notice of oil drainage on the instrument panel.
(7) Remove all spark plugs, and direct the spray of
corrosion pre venti ve into all cylinders, in turn,
through spark plug holes while the crank6haft is
turned slowly.
(8) With the crankshaft static, spray each cylinder
wall for minimum full coverage. Do not turn the
crankshaft thereafter.
(9) Spray the mixture into the oil filler neck, and
S~ction
replace cap.
(10) Spray the crankcase through the drain plug holes.
(11) Seal all crankcase openings with nonhygroscopic
plugs. Either reinstall all spark plugs or install dehydrator plugs in all plug holes. If possible, place a
small bag of De-moist or similar hygroscopic
material in the air scoop mouth to fill the opening.
Water-proof paper or cloth should separate the bag
from scoop walls. Seal the scoop opening with waterproof material. Post a notice of these measures on
the instrument panel.
(12) Crated engines may be treated by following
steps (1), and (7) through (11). Also remove rocker
covers, and spray valve stems.
(b) The treatment described in the preceding
paragraph should be repeated at intervals of not over
30 days during storage.
5. PREPARATION OF ENGINES FOR SERVICE
AFTER STORAGE.
(a) Engines prepared for storage in accordance with
paragraph 4 may be placed in service immediately
after making the following checks:
(1) Turn the propeller slowly by hand at least four
or five revolutions to determine that the cylinders
are free of any accumulation of water, oil, or fuel
and that the valve operate freely. The stems of any
valves that are sticking should be lubricated generously with a mixture of gasoline and lubricating oil.
Continue to turn the engine over by hand until all
evidence of sticking valves has been eliminated. If
the mixture of gaSOline and lubricating oil does not
free all the valves, the necessary repairs should be
made before the engine is placed in service.
(2) After starting the engine, if the spark plugs are
found to be fouled from excessive engine oil, they
should be removed and washed with gasoline or
acetone.
5
INSTALLATION IN AIRPLANE AND REMOVAL
1. ENGINE MOUNTING.
(a) Place hoist hook in engine lifting eye, and detach
engine from assembly stand.
(b) Raise engine to proper height, and position it on
aircraft mount. Install four 7/16 in. dia. mount bolts
and nuts.
(c) Remove all protective covers such as the card
board covers over exhaust ports and plug from the
carburetor inlet, 1/8-inch pipe plug from oil pressure
gauge line and primer connection plug.
(d) Connect the following controls at the engine:
(See figure 6. )
(1) Throttle control rod or wire.
(2) Hot air control.
(3) Oil temperature gauge.
(4) Carburetor fuel supply pipe.
(5) Tachometer cable.
(6) Magneto switch wires.
(7) Oil pressure gauge line.
(8) Primer Outlet.
(9) Primer Inlet.
(10) Starter power and control cables.
(11) Generator wires.
(12) Carburetor mixture control.
2. FUEL AND CARBURETOR SYSTEM.
(a) The primer may be connected either at the intake
manifold at oil sump connection or at the intake port
of each cylinder. At below zero temperatures the
cylinder intake port location is recommended.
(b) Mount the air intake housing on the carburetor
with the scoop opening forward, and install the air
filter. Connect the 2 in. dia. hot air inlet at the right
rear corner of the housing to the supply tube provided in the aircraft.
Note: Be sure to push the filter cam lock studs home
before turning.
3. OIL SYSTEM.
Screw the oil temperature capillary into the tapped
hole centered in the oil pressure screen cap. (See
figure 8.)
11
TO STARTER LErER
TO BATTERY
TO OIL PRESS GAGE
TO TACHOMETER
TO IGNITION SJ1IITCH
.:r.t1";;~~~:::::jt:} TO JIOLTAGE REGULATOR
'"
TO OIL TEMP GAGE
TO PRIMER OUTLET
TO MIXTlJRE CONTROL
TO CARB HEAT CONTROL
TO TfiROTTLE CON1I<0L
TO PRIMER INLET
TOOASTANK
Figure 6. Typical Installation Diagram.
I .679
±
Om'---1-............r-1679
±.002
DRILL .257-DEPTH .81
C'SINK Iloox.34 DIA.
TAP .3125-18NC-4 DEPTH 62
PD. .2764-2779-4
VIEW A-A
D
Figure- 7. Installation Drawing.
12
:
RADIO
SHIELDED
PLUG
LORD BUSHING
NO. H-3006
PORTS
5/S 18 N.F. 3 HOLE FOR
TEMPERATURE MEASUREMENT
HOT AIR IN
ABCDE F GHJ KL MN0P -
STARTER
MAGNETOS TACHOMETER DRIVE S.A.E. STD. 1/2 ENGINE SPEED
GENERATOR
SUCTION OIL SCREEN
PRESSURE OIL SCREEN
OIL FILLER
ENGINE MOUNT BRACKETS
OIL SUMP DRAIN
NO. 10 SPLINE TYPE SHAFT
CARBURETOR (MARVEL)
OIL GAUGE
FUEL PUMP (OPTIONAL EQUIP.)
BREATHER ELBOW - C'CASE (AN-842-10)
S.A.E. No. 3 FLANGE TYPE SHAFT
Figure 8, Installation Drawing.
13
8 BOLTS
.375 0.0.
EQUALLY SPACED 370
.624 DIA.
623
1---+-+------------
I
9
41 / 16
1-<----35%-----_:
K
CLEARANCE REQUIRED
TO REMOVE STARTER
AND GENERATOR
LENGTH
622-621 REAM .72 X90 0
C'SINK 8 HOLES
EQUALLY SPACED
14
~
,
\
,
'" _
i
1. _
--------<0-1-_- 9 5/S ---....u
~4 00
-j
3.81
5/16
,I
""
'"
2217/32
~~~ I
5.251 ~
5.249
.
\ I
,
----I
1
I:
6 1/ 2 DIA,..j
,v'
I
18 bi
VIEW B-B
32
27@.
, 32
G
2
'4
H
J
~ EXHAUST PORTS
)2
'4
1;8 PIPE TAP FOR
MANIFOLD PRESSURE
NO 50 DRILLED OPENING
IS REQUIRED IN THE
COMPANION FITTING
Figure 9. Installation Drawing.
14
23 '/4
I"
(8) Primer inlet and outlet connections.
(9) Starter power and control cables.
(10) Generator wires.
(11) Carburetor mixture control.
(12) Hydraulic valve cable (C145-2H).
(b) Attach chain hoist to engine at lifting eye, and
relieve mount of engine weight.
(c) Remove engine mount bolts.
(d) Carefully remove engine from mount, lower and
fasten engine to a suitable assembly stand.
4. ENGINE REMOVAL.
(a) Disconnect following controls at engine:
(1)
(2)
(3)
(4)
(5)
Throttle control rod.
Carburetor air heat valve control.
Oil temperature gauge line.
Carburetor fuel supply pipe.
Tachometer cable.
(6) Magneto switch wires.
(7) Oil pressure gauge connection
Section 6
GENERAL OPERATING INSTRUCTIONS
1. BEFORE STARTING.
a. Perform the ''Daily Inspection" described herein.
b. Place ignition switch in "OFF" position.
c. Place mixture control in "FULL RICH" position.
d. Turn fuel supply valve to "ON" (full tank).
e. During winter operations turn propeller by hand
at least six revolutions to loosen congealed oil and to
listen for unusual noises.
2. STARTING.
a. Close throttle to idle stop.
b. Place Main Line Switch in "ON" position.
c. Turn ignition switch to "BOTH" position.
d. Open throttle approximately 1/10 of range.
e. Engage starter, and operate primer as required
by temperature.
Never re-engage starter while propeller
is turning.
NOTE
Do not prime a hot engine. If over-primed,
crank with ignition switch "OFF", throttle
wide open to clear.
3, WARM-UP AND GROUND TEST.
a. Immediately after starting adjust throttle to 800
R. P. M. and observe oil pressure. If no pressure is
indicated within 30 seconds, stop and investigate.
b. After-at least one minute at 800 R. P. M. , increase
speed to 1200 R. P. M. and continue warm-up until
engine responds to normal throttle movement. Part
of this period may be used in taxiing.
c. Increase engine speed to 1700 R. P. M. only long
enough to check performance as follows:
NOTE
Due to design changes in today's higher
output engines the comparison of single
magneto operation versus both magnetos
is no longer a sound criteria for evaluation of magneto operation. Therefore all
magneto checks should be performed on a
comparative basis between individual
Right and Left magneto performance.
(1) The purpose of the magneto check is to determine that all cylinders are firing. Magneto drops of
up to 150 R. P. M. are not 'unconnnon, but if a cylinder
is not firing, engine roughness will be very evident
and the magneto drop will be considerably greater.
(2) Move the ignition switch first to "R"position and
note the R. P. M., then move switch back to "Both"
position to clear the other set of plugs. Then move
switch to "L" pOSition and note the R. P. M. The difference between the two magnetos operated singly
should not differ more than 75 R. P. M.
d. Check oil pressure. Should be 30-45 lbs. / sq. in.
e. Check oil temperature. Should show a slight rise.
f. Retard throttle, and make sure mixture control
is in "FULL RICH" position and carburetor air heat
control is in "COLD" position (unless icing conditions
exist at airport altitude).
Ir----~~~~...........--,:IO~]
If ice forms in carburetor during warm-up
it must be cleared. Do not operate at high
R. P. M. longer than 30 seconds on the
ground under other conditions.
4. TAKE- OFF AND CLIMB.
a. Open throttle to full speed stop.
b. R. P. M. may not reach rated speed until craft is
air-borne. Maintain rated R. P. M. only until immediate obstacles are cleared; then reduce to climb power setting.
Cylinder head temperature must not exceed values listed in specifications during
climb,
5. CRUISING.
a. Do not exceed recommended cruising R. P. M. or
manifold pressure for long periods. Excessive speeds
and loads hasten wear and increase operating cost.
b. Abnormal cylinder and oil temperatures or subnormal oil pressure may indicate depletion of oil,
incorrect operation or inCipient trouble. Any fluctuation in oil pressure, irregularity in R. P. M. , rough
running or any sudden or continuous rise in temperature is a warning of trouble. Land quickly and investigate.
c. At any cruising altitude adjust mixture control
for best rich power by moving toward "LEAN" position to obtain maximum R. P. M. with fixed throttle;
15
then return toward "FULL RICH" until R. P. M. drops
just perceptibly. Readjust for each change in power
or altitude.
Excessively lean fuel- air mixture will
cause overheating and may cause detonation. Do not lean the mixture unless an
increase in R. P. M. results.
6. LANDING.
a. Before starting approach, return mixture control
to "FULL RICH" position.
b. Apply full carburetor air heat before retarding
throttle. Return to "COLD" position.
NOTE
If approaching a field whose elevation is
5000 feet or more above sea level adjust
fuel-air mixture for best power in level
flight near field elevation.
leave them open until engine stops.
b. Allow the engine to idle at 800 R. P. M. until cylinder temperature has been reduced appreciably below
normal operating temperature.
c. If spark plugs tend to foul rapidly at idling speed,
advance throttle briefly to clear them before stopping.
d. Close throttle to idle stop.
e. Stop the engine by mOving mixture control to the
"LEAN" limit, where it acts as an idle cut-off.
NOTE
Do not open throttle after stopping. Opening the throttle actuates the accelerator
pump.
f. After the engine stops turn ignition switch to "OFF"
pOSition, and close the fuel supply valve.
8.
c. During a long approach maintain 1000 to 1200
R. P. M. and "gun" the engine at intervals to prevent
fouling.
d. Close throttle before landing.
7. STOPPING THE ENGINE.
a. Open cowl flaps, if installed, while taxiing, and
CARBURETOR HEAT CONTROL.
The engine should be operated on COLD AIR at all
times, except when operating under conditions where
icing is likely, inwhichcasethe carburetor air control
should be placed in the FULL HOT position. During
the warm-up period, landing approach and during long
glides, carburetor heat control should be in the FULL
HOT position. To obtain the maximum R. P. M. for
take-off and climb, and atmospheric conditions permitting, the carburetor heat control should be in the
FULL OFF position. There is a drop from 100 to 200
engine R. P. M. when the carburetor heat is FULL ON.
Section 7
ENGINE TROUBLES AND SERVICE REPAIRS
1. FAILURE OF ENGINE TO START.
a. Lack of Fuel.
(1) Check whether there is sufficient gasoline in
airplane tank and a definite flow of gasoline to the
carburetor.
(2) Check gasoline shut-off valve for being in the
FULL OPEN pOSition.
(3) Check for carburetor float being stuck, and for
clogged screen and jets.
(4) Check the gasoline tank caps to make sure their
vent holes are open.
b. Improper Priming.
(1) Weak intermittent explosions followed by puffs
of black smoke from the exhaust pipe would indicate
overpriming or flooding. Excess fuel may be cleared
out of the combustion chamber by setting the throttle
to the FULL OPEN position and cranking engine three
or four revolutions with the ignition switch in the OFF
position.
(2) Iftheengineisunderprimed, whichis most likely
in cold weather and with a cold engine, repeat the
same instructions given for starting.
c. Defecti ve Ignition.
(1) Check the ground wire between the magnetos and
switch. The grounding of this wire will prevent magnetos from firing.
(2) Check all spark plugs for being clean and having
correct gap setting. Gap should not exceed 0.022". For
recommended gap refer to Service Bulletin M77-lO.
16
(3) Check the magneto breaker pOints and see that
they are clean and free from oil.
d. Cold Oil. In extremely cold weather it is advisable to preheat the cylinder oil before attempting to
start the engine, to insure lubrication and obviate
having to run the engine an excessively long time to
get oil temperature up to 75° F.
It is also recommended that the engine be cranked
by pulling propeller through several revolutions by
hand (make sure the ignition switch is at the OFF
position) to help break the drag created by cold oil
between the pistons, piston rings, and cylinder walls.
e. Hot Engine. Do not prime, The engine will usually start without priming. If over-primed, remove
excess fuel vapor from cylinders by cranking the engine at least six revolutions with ignition switch "OFF"
and throttle wide open.
2. LOW OIL PRESSURE.
a. Check the quantity and quality of oil in the oil
sump.
b. Check for dirt in the oil screens and clean thoroughly.
c. Check oil pressure relief valve for having dirt at
seat, and for plunger sticking in its guide.
d. Check for worn bearings.
e. Check for proper functioning of oil pressure
gauge.
3. mGH OIL TEMPERATURE.
a. Insufficient cooling.
b. Insufficient oil supply, Should be 8 quarts.
c. Check oil for proper viscosity. (See lubrication
chart, page 5.
d. Check for excessively lean fuel mixtures.
4. LOW POWER.
a. Check ignition system in general.
b. Check for full opening of throttle and for proper
closing of carburetor air heater valve,
c. Check gasoline for proper octane and volatility.
Automobile gasolines regardless of octane rating are
unsuitable for use in aircraft engines, and will not
only cause loss of power and overheating but will result in serious damage.
d. Check for low compression in cylinders.
5. ROUGH RUNNING.
a, Check propeller for balance, pitch, track and
tightness of attaching bolts.
b. Remove and clean spark plugs. Set electrode gaps
as specified in Service Bulletin M77-IO. Test plugs in dry
compressed air.
c. Test for uneven cylinder compression by turning
propeller, with ignition switch "OFF", or, with a
gauge installed alternately in upper spark plug holes,
Crank engine with starter and compare indicated pressures.
d. Test ignition cables for high tension breakdown.
e. Remove magnetos. Test condensers, timing,
operation.
£. Remove carburetor; disassemble, clean, test it.
g, Check engine mount bolts and Lord bushings.
6.
a.
b.
c,
d.
e.
f.
g,
ENGINE FAILS TO ACCELERATE PROPERLY.
Engine not suffiCiently warm.
Mixture too lean (use "FULL RICH" on ground).
Carburetor idling jet mis-adjusted or plugged.
Carburetor accelerator pump inoperative.
Low octane fuel, water in fuel, dirty fuel.
Carburetor air heat valve improperly adjusted.
Air intake restricted.
Section 8
SERVICE INSPECTION AND ASSOCIATED
MAINTENANCE
1. DAILY INSPECTION.
a. Check oil and fuel levels and replenish if necessary.
b. Check oil and fuel systems for leaks and plugged
vents. Remove any oil from exterior.
c. Check for free operation of throttle, mixture
control, and carburetor heat control. Clean fuel filter
bowl if necessary.
d. Check the entire engine for missing or loose nuts,
screws, bolts, etc.
e. Check safety wiring, baffles, and ignition system.
f. Check propeller for pits, cracks, nicks, and security of mounting.
g. The air filter should be checked daily for:
(1) Cleanliness.
(2) Condition of seals and gaskets.
(3) Condition of air box and ducting.
(4) Be absolutely sure that no air leaks exist in induction system at any point that would allow unfiltered
air into engine.
2, lOO-HOUR INSPECTION.
a. Remove and inspect general condition of engine
cowling.
b. Wash the exterior of the engine thoroughly with
a good cleaning solvent. This may be done with a
brush but spraying is preferable. Keep away from
electrical equipment.
c. Check engine mounting bolts and brackets for
tightness and security.
d. Remove rocker box covers and inspect general
condition of all parts. Interior of covers should show
complete coverage with oil for proper lubrication.
e. Check intake manifold, elbows and rubber connections for condition and security.
f. Remove spark plugs, clean, check gap clearance
for being between. 015" and . 022", test and replace,
using solid copper gaskets.
g. Check all high tension cables and terminals for
condition and security.
h. Check propeller for condition, security of mounting and proper track. Blades should track within
1/8 inch.
i. Remove and clean sediment bowl and screen, replace, tighten and safety.
j. Remove drain plug from bottom of carburetor
float chamber, remove and clean strainer. Turn fuel
on and flush out any water or sediment or trapped air,
replace strainer and plug, safety same.
k. Check for full range movement of carburetor
throttle, mixture control lever and carburetor heater
control valve.
1. Check all air pressure baffles for cracks, position and security of fastening.
m. Remove, clean in fresh cleaning solvent and inspect the carburetor air filter. If the flocking on the
surfaces is worn through so as to expose the metal
screen the filter will not be effective and must be replaced with a new part. If the original filter is satisfactory, dry it thoroughly; then dip it in clean engine
lubricating oil, and allow it to drain for eight hours
or so before installing. Inspect the air scoop for
cracks, deformation of the air filter retaining parts
and obstruction of the drain tube. Repair or replace
parts as necessary to correct such conditions.
n. Remove oil screens from bottom of crankcase
cover. Clean, inspect and replace them. Use new
gaskets,
o. Remove magneto breaker cover and thoroughly
clean and dry the breaker mechanism; check contact
pOints for condition in general. (See Section on Magnetos for further instructions. )
p. Check the exhaust system for cracks or looseness
in mounting and connections. Check exhaust port for
blown gaskets. Check cabin heater for any possibility
of exhaust gas leaks.
17
q. Check starter and generator for leaks and security. Leakage at generator mounting may mean a
defective or worn oil seal. Wipe or wash off any oil
seepage at pinion gear shaft in starter adapter. Should
the oil seal ever need replacing on this shaft replace
only with a seal furnished by the manufacturer of the
starter.
r. Check engine instruments for tightness of mounting and for proper functioning.
3. MAJOR OVERHAUL OR REMANUFACTURE,
After recommended hours of operation the engine
should be removed from the airplane and overhauled at
a Continental Authorized Service Station or exchanged
through a Service Station or Dealer for a remanufactured engine.
Section 9
ADJUSTMENT, REPLACEMENT AND MINOR
REPAIRS
1. CARBURETOR
(a) The carburetor is attached to the mounting pad
of the oil sump with a gasket between the parting
flanges and is retained by four 1/4 inch castle nuts.
(b) The carburetor air intake and filter assembly is
mounted on the base of the carburetor with a gasket
between carburetor and air intake and is retained by
four castle nuts.
(c) Controls connected to the carburetor are:
(1) Cable to throttle lever at right side.
(2) Cable to mixture control lever at left side.
(d) The fu·sl inlet is a 1/4-inch pipe tap connection
located at the back near the bottom of the main body.
(e) The carburetor may be removed from the engine
by detaching the fuel line, throttle and mixture controls removing the air intake assembly and the four
castle nuts at the mounting pads.
(f) For adjusting procedure, refer to Section 14.
2. MAGNETO INSTALLATION AND TIMING TO THE
ENGINE.
(a) Turn the magneto shaft backward, to prevent the
impulse coupling pawls engaging, until the marked
distributor gear tooth is opposite the pointer, visible
through the inspection window in the top of the
magneto case. This places the magneto in No •. l
firing position.
(b) Turn the crankshaft forward until No.1 piston is
on its compression stroke and at the full advance
firing angle for the magneto to be installed. (Refer
to Section 1 for angles.)
(c) Install the magneto and gear assembly with
timing marks still aligned. Always use a new gasket.
(d) Tighten the mounting nuts enough to hold magneto
in position against the accessory case. Before
checking exact breaker opening position, rotate
magneto in a clockwise direction by tapping the
mounting flange until it is near the end of travel
permitted by the slots.
Turn crankshaft backward slightly, and bring
slowly up to firing position to take any backlash out of
the driving train. Insert a .0015 web feeler between
breaker pOints and tap magneto in a counterclockwise
direction until the exact point of release is reached.
Tighten mounting nuts and recheck timing by backing
crankshaft about 100 and then turning it slowly
forward to determine if the feeler is released the
instant the crankshaft reaches the correct firing
angle. The use of a timing light is recommended for
more accurate timing.
18
3. IGNITION WIRING.
(a) Refer to figures 10, 11, or 12 where the complete ignition wire system is diagrammed and the firing order given.
4. STARTER.
(a) The starter is located at the top and center of
the crankcase gear cover and is secured by three
5/16 studs with plain nuts on the lower part of the
starter adapter and two 5/16 bolts at the top of
starter. The bolts extend through the crankcase,
crankcase gear cover and starter adapter into the
starting motor.
(b) A gasket of .006" thickness is placed between
crankcase gear cover and starter adapter.
CYL.NO.6
CYL.NO.S
CYI..NO.4
CYI..NO.3
cn.NO.2
CYL. NO. I
RI6HT IIIA6NETO
ENGINE
RR/Nt; ORDER
/-IS'$-Z-S-4
Figure 10. Ignition Wiring Diagram For
Bendix S6LN-21 Magnetos.
en. NO.6
eYL.NO.5
eYl. NO.6
en. NO.5
en. NO.4
en. NO.3
eYL. NO.4
eYL. NO.3
en. NO.2
en. NO.1
eYL. NO.2
en. NO.1
MAGNETO
ENGINE
FIRING ORDE
1-6-3-2-5-4
Bendix S6LN-21 Magnetos.
LEFT MAGNETO
GROUND
RIGHT MAGNETO
ENGINE
FIRING ORDER
1-6-3-2-5-4
Slick 664 Magneto.
crankshaft gear before the electrical contact is made
in the starter switch. The pinion adjusting stud must
provide 9/16" travel of the pinion when the starter
switch is fully closed. The lock nut on the stud may
have to be moved to the other side of the lever to obtain this adjustment. It is also important that the
lever, whether operated by cable or wire, have a
spring with sufficient tension to return the lever to
its fully released position. When the lever is fully
released there should be 1/16" clearance between
the lower end of the lever and the clutch as shown in
the illustration. Never ENGAGE starter switch when
the propeller is MOVING.
Figure 13. Starter.
(c) Care should be taken when removing the starter
so as not to drop the pinion gear and clutch from the
adapter when starter is being assembled or disassembled.
(d) To help eliminate possible starter gear damage
resulting from an incorrect adjustment, make certain
all switches are "OFF" and set pinion adjusting stud
so that the starter gear is fully engaged with the
5. GENERATOR.
(a) The generator is attached to a pad at the lower
rear side of the crankcase cover by three cover studs,
elastic stop nuts and plain washers. The generator
gasket extends under the tachometer drive housing,
which must be removed to replace the gasket.
(b) The drive assembly, retained on the generator
shaft by a slotted nut and cotter pin, is removed
with the generator. It consists of a coupling hub,
keyed to the shaft, two rubber bushings and a steel
retainer, which fit into the hub slot, a steel sleeve,
which extends from the retaining nut to the hub, and
a gear, whose drive lugs fit between and dri ve the
bushings.
(c) It is recommended that aU replacements of
generator drive parts be made with those listed in
the current Parts Catalog.
19
Section 10
OVERHAUL INSTRUCTIONS
DISASSEMBLY, CLEANING AND INSPECTION
1. GENERAL.
(a) The engine should be mounted on a suitable
assembly stand which will permit it to be placed in
the upright position for some operations and with its
left side downward for others. The stand should
provide clearance for removal of accessories, cylinders, oil sump, manifolds and other parts.
(b) Spray the exterior of the engine with an approved
cleaner to remove all traces of dirt and grease.
Precautions should be taken to prevent cleaning fluid
entering accessories.
(c) Remove and discard all safety wiring, palnuts,
lock washers and cotter pins where necessary, before each part is disassembled from engine.
2. PRELIMINARY OPERATIONS.
(a) Ignition cables (SF6LN-12 Magnetos) - Detach
cables from spark plugs and magnetos. Remove nuts
securing brackets and remov:e ignition wiring.
Cable and Plate Assemblies (S6LN-21 Magnetos)
- Loosen union nuts, and remove spark plug elbows
from plugs. Remove 4 screws which attach each
outlet plate to its magneto, and withdraw plate and
grommet. Remove all bracket attaching nuts,and remove brackets from studs. Lift each cable and plate
assembly from the engine.
(b) Spark Plugs - Remove upper and lower plugs.
(c) Magnetos - Remove nuts that fasten flanges to
crankcase cover, and remove magnetos.
(d) Starter - Remove nuts that fasten starter to
crankcase cover and remove starter.
(e) Generator - Remove the three nuts that hold the
tachometer drive housing then remove the housing
which will give more accessibility to the removal of
the generator. Remove the three nuts holding
generator in place and remove generator.
(f) Carburetor Air Intake - Remove the four nuts
that hold the carburetor air intake to the carburetor
and remove air intake.
(g) Carburetor - Remove four nuts which fasten the
carburetor to the mounting flange on the oil sump,
and remove carburetor.
3. DISASSEMBLY.
(a) Intake Manifolds - Unfasten clamps which secure
hose connecti'ons to intake elbows and remove the
three cap screws from each of the two intake manifolds and remove the manifolds.
(b) Oil Sump and Oil Screens - Remove the two oil
screens from the bottom of the crankcase cover.
Remove 3 hex head screws which attach old type
covers to sumps - or 5 hex head screws which attach
the new type cover to the sump. Remove 14 nuts
which attach the sump to the crankcase studs, and
lower the sump clear of the engine.
20
NOTE
The oil gauge should be removed before the
sump to prevent damage to it.
(c) Rocker Box Covers - Remove the 1/4" screws
that fasten the rocker box covers to the cylinder head
and remove covers.
(d) Push Rods and Rocker Arms - After covers are
removed push out rocker arm shaft with the finger,
or if necessary, use an aluminum drift and slightly
tap out. Remove rocker arms from cylinder head
and push rods from their housings.
NOTE
Both valves must be closed before rocker
shafts are removed. If desired, rockers and
pushrods may be removed with cylinders and
disassembled later.
(e) Cylinder and Pistons.
(1) Loosen clamps which secure the hose connections
at foot of the pushrod housing. Push clamp and rubber hose back up on the housing toward cylinder head.
(2) Turn crankshaft until piston within cylinder to be
removed is at top of the stroke.
(3) Remove the six cylinder hold-down nuts and pull
off cylinder from the crankcase.
Do not allow piston and connecting rod to
drop down when cylinder is removed, as damages will result.
(4) After removal, place cylinders on wood or
appropriate carrier to prevent damage to the bottom
end of barrels.
(5) Push piston pin out and remove piston from the
connecting rod. If necessary, use aluminum drift to
drive out piston pin, being careful to support the
piston pin in the hand during this operation to prevent
damage to the connecting rod.
(6) Remove the rings from the ring grooves of all
pistons. Discard all rings.
(7) Placing the cylinder over a wooden stand, shaped
to fit the inside of the cylinder head, compress
valve springs in rocker box, uSing a suitable valve
spring compressor. (See figure 14. ) Remove the
seat locks with long nose pliers. Release the compressor, and remove the spring retainers and valves.
(3) Remove the six 5/16-inch nuts holding the
crankcase cover to the crankcase. Lift the cover off
as a complete unit - the oil pump, relief valve and
tachometer drive units remain intact in the crankcase cover.
(4) Remove the four 1/4-inch cap screws holding the
cam gear to the camshaft and remove gear.
(5) Remove the four 1/4-inch cap screws holding the
crankshaft gear to crankshaft and remove gear.
(6) Remove all 1/4-inch nuts from the bolts holding
halves of crankcase together, located on centerline of
crankcase on both top and bottom of the engine.
(7) Remove the 7/16-inch nuts attached to the long
stud and thru bolts near front of crankcase on the
No. 1-3-5 cylinder side at bottom of case. Remove
the remaining through bolt attaching nuts, lockwashers
and plain washers.
(8) Rotate the engine stand until No. 2-4-6 Side is
downward. Drive out the through bolts carefully,
using a soft brass drift.
NOTE
Remove dowel screws at rear of upper flange
and above and below crankshaft at front in old
type case by careful tapping.
Figure 14.
Compressing Valve Spring For
Installation and Removal of Locks.
Care must be taken when removing valves, to
prevent burrs on valve stem from scratching
valve guides.
(9) Carefully lift the No. 1-3-5 crankcase off and lay
aside, with contact surface up. Do not pry castings
apart, or damage will result.
(10) Lift crankshaft with connecting rods attached,
out of crankcase.
(11) Remove crankshaft oil seal from front of shaft
and remove all bearing inserts and thrust washers
from both halves of the crankcase.
(12) Remove the camshaft and starter pinion pivot
from the crankcase.
(13) Remove all connecting rods from the crankshaft
carefully, noting their position on the shaft before
disassembling (Figure 16).
(f) Crankcase.
(I) Remove the six push rod housing flanges by unscrewing the 1/4-inch nuts which secure them to the
crankcase.
(2) Remove the push rod sockets from the hydraulic
valve lifters. Remove the hydraulic unit from each
lifter with the aid of a small wire hook (fig. 15).
Keep tappets numbered according to the order removed - keeping assemblies grouped together.
NOTE
The plunger in the hydraulic unit is not interchangeable in the cylinder. These parts are
fitted together at factory so as to give the
proper rate of leak-down.
NOTE
The valve tappet cam follower body cannot be
removed until the crankcase is disassembled.
Place push rod housing connections over ends
of cam follower to prevent their falling into
crankcase while crankcase is being disassembled. (See figure 23. )
Figure 15. Removal of Hydraulic Unit
From Cam Follower Body.
21
supports for scores or deep scratches and smooth out
with crocus cloth if necessary.
(2) Cylinders - Remove acculuation of oil and dirt
from between the cooling fins. Remove carbon from
inside of cylinder head with carbon-removing compound, or by soft grit or vapor grit blasting if
equipment is available.
(3) Valve mechanism - Clean thoroughly of accumulated oil, the rocker arms, rocker shaft, spring
seat, springs, retainer and intake and exhaust valves.
(4) Oil Sump - Unscrew drain plugs and flush out the
oil sump, removing all accumulated sludge.
(5) Crankshaft and Connecting Rods - Clean
thoroughly with kerosene, blowing out all oil lines.
The cleaning fluid must be kept free from
grit and foreign particles.
Figure 16. Assembling No. 1 Connecting Rod.
(14) Remove pushrod housing connections from ends
of cam followers, and remove cam followers from
both halves of the crankcase.
(g) Crankcase Cover Assembly.
(1) Remove the four oil pump cover cap screws and
lift out the cover and two oil pump gears.
(2) Remove the oil pressure relief valve cap, gasket,
spring and plunger from the outside of the cover.
4. CLEANING.
(a) General.
(1) After the engine has been disassembled, clean
the major subassemblies and miscellaneous parts in
accordance with the instructions below.
(2) The cleaning fluids prescribed herein must be of
such a type that will not attack metals - particularly
bronze and aluminum alloy parts.
(3) After the subassemblies and miscellaneous parts
have been cleaned, thoroughly drain off excess cleaning fluid and dry with compressed air.
(4) Treat steel parts with a rust preventive after they
have been cleaned and dried.
(b) Cleaning of Engine Parts - Spray the following
assemblies and parts with kerosene. Particular
attention must be given to the special cleaning
instructions which are prescribed for each the subassemblies and parts.
(1) Crankcase - Remove the two pipe plugs from the
oil lines, clean out both halves and blowout all oil
passage tubes in both halves. Examine cam journal
22
(6) Pistons and Piston Pins - Do not use wire
brushes or scrapers of any kind. Soft and moderately
hard carbon deposits may yield to solvent action,
which should be tried first in preference to harsher
methods. If the deposits remain, blast the head with
soft grit or by the vapor grit method, first having
installed tight fitting skirt protectors. Ring grooves
may be cleaned by pulling through them lengths of
binder twine or very narrow strips of crocus cloth.
Do not use automotive ring groove scrapers, since
the corner radii at the bottoms of the grooves must
not be altered, nor any metal removed from the
sides. Discoloration and light scoring need not be
removed from piston skirts. The use of abrasive
cloth on the skirts is not recommended, because the
diameters and contours must not be altered. Heavily
scored or burned pistons should be discarded.
(7) Gears - Clean cam, magneto drive, generator
drive, crankshaft, starter, starter pivot and oil pump
gears, thoroughly with kerosene and dry with compressed air.
5. INSPECTION.
(a) Visual Inspection. A preliminary visual inspection of all parts will indicate whether any are deformed, corroded, scored, galled, pitted or otherwise
damaged beyond repair. A more careful visual inspection should be performed on each part to determine the need for minor repair, such as stoning
thread chaSing or lapping. Due to the difficulty of
detecting cracks and if a crack is suspected in any
aluminum casting, the part should be etched. Visual
inspection should also include a detailed observation
of all areas, holes, pockets, and threads to ascertain
that all foreign material, cleaning compound and
abrasives have been removed.
(b) Etching. Before etching any area to be inspected
for cracks, all enamel, carbon and oil must be removed. The surface should be clean and dry. The
following procedure and precautions apply.
(1) Paint the area with a solution made by dissolving caustic soda in water (at room temperature)
in the proportions of 2lbs. of caustic soda per
gallon of water. Expose the aluminum surface to
the cleaning action of the solution for no more than
60 seconds.
(2) Immediately rinse the part in running water;
then netraulize the action with a solution of one part
nitric acid in four parts water. Allow the dilute acid
to act only long enough to remove the black deposit
left by the alkali.
(3) Rinse the part thoroughly and dry with compressed air. The etching process will leave the surface perfectly clean, but the black deposit will remain in cracks and deep scratches. These may be
seen more clearly with the aid of a magnifying glass
and, thus distinguished.
(c) Dimensional Inspection. Diametrical and end
clearances, interference (tight) fits, out-of-roundness
and "run-outs" of all important part dimensions are
listed in the Table of Limits, Section 13. In most
instances, each of two mating parts must be measured
and their dimensions compared to determine whether
or not the fit is correct. This applies to tight fits as
well as running fits. When a tight fit requires that
the fem~ part be heated before insertion of the male
part, both parts must be measured at the same room
temperature before heating of the former. Since new
bearing inserts will be installed in the crankcase and
all connecting rods, it is unnecessary to measure the
new bearing diameter. For this reason and others,
certain parts should be inspected for individual dimensions against individual limits or the serviceable
limit of fit. Some dimensions for this purpose are
listed in Section 13. Other necessary dimensions are:
(See Table IX. )
NaI'E
Reground barrels. (.015 inch oversize)
must be within limits No. 36A, Section 13,
and taper may not exceed. 002 inch, with
largest diameter, ifany, at bottom. Bore
must be less than. 001 inch out-of-round,
and less than. 001 inch out-of-square with
flange, full indicator reading, in length of
barrel.
Table X. provides data for proper inspection by the
Magnaflux method. When- this process is used, the
following precautions must be observed to assure
reliable results and safe condition of inspected parts.
(1) Parts must be free of carbon and oil.
(2) Crankshafts and piston pins must be polished before inspection.
(3) All parts should be inspected for forging laps,
seams and grinding cracks which may have opened in
service.
(4) The suspension liquid should be maintained at a
strength of 1-1/2 ounce of red Magnaflux paste No.9
per gallon kerosene.
(5) Before magnetization, all small openings and
oil holes leading to obscure cavities must be plugged
with either a hard grease or similar non-abrasive
material, which is readily soluble in lubricating oil,
to prevent accumulation of magnetic particles where
they cannot be removed.
(6) All parts must be completely demagnetized after
inspection and between successive magnetizations.
Demagnetization is preformed by inserting the part
in an alternating current demagnetizer, from which
it is withdrawn slowly. Irregular shaped parts must
not be withdrawn at a rate of more than 12 feet per
minute.
(7) The magnetic substance must be removed completely from all parts after inspection. All plugs
must also be removed. Both the wet continuous
method and the wet reSidual method are used. In the
former process, the magnetic solution is poured over
the part while it is mounted between the poles of the
magnetizer, and application of the fluid is stopped as
the magnetizing current is started. In the wet ·residual process, the part is immersed in the magnetic
suspension fluid after it has been magnetized. Table
X shows the method recommended for inspection of
each kind of part.
NOTE
If the crankshaft is suspected of any defect
(d) Magnaflux Inspection. Parts listed in Table X
should be inspected at each overhaul by the Magnaflux
process or an equivalent method of crack detection.
not firmly established by inspection after circular magnetization it should be demagnetized
and then, magnetized lonKitudinally for further
inspection.
T ABLE IX. Table of Dimensions
FEATURE
Intake Valve Guide Bore
Exhaust Valve Guide Bore •
Cylinder Barrel Bore • • •
C-125 Piston (Std) Diameter
*At Top of Skirt. • • • •
*At Bottom of Skirt . • • • • •
C-145, 0-300 (Std) Piston Diameter
*At Top of Skirt • • • • • . • . • • • •
*At Bottom of Skirt (Above 4th Groove)
Piston Pin Bore Diameter • •
Piston Pin Diameter. . • . • •
Connecting Rod Bushing Bore.
Rocker Shaft Diameter. • • •
Rocker Arm Bushing Bore ••
Camshaft Journals Diameter.
NEW DIMENSION
(INCHES)
.3432 - .3442
.437 - .438
4. 062 - 4.064
4.051 - 4.053
4. 054 - 4. 055
4. 049
4.052
.9217
. 9214
.9230
• 6082
.6097
1. 3725
-
4. 050
4.053
.9221
.9216
.9235
. 6087
.6107
1.3735
* Measured at right angles to pin bore.
23
Two methods are used to support parts between poles
of the magnetizer for circular magnetization. They
are:
(a) Pads of copper braid or soft lead plate are installed on the pole pieces, and the part is clamped
tightly between them to assure good contact and to
prevent burning.
(b) The parts are strung on a copper rod, which is
he ld between the poles of the magnetizer.
Following demagnetization the parts must be
thoroughly cleaned by spray and air blast. When dry,
the parts should be flushed in a corrosion preventive
oil.
(e) Inspection of Engine Parts.
(1) Crankcase.
a. Check thoroughly for fatique cracks.
b. Examine camshaft bearing, thrust washers and
starter pinion pivot for cracks and scratches and
excessive wear.
c. Check studs for damaged threads and straightness.
(2) Cylinders.
a. Cylinder Heads - Examine cylinder head for
cracks. Small cracks found at head fins are not
cause for rejection. However, if cracks are of
appreciable size and indicate ultimate failure, re place the cylinder.
b. Cylinder Barrels - Inspect cylinder barrel flange
for nicks, evenness and for condition of cylinder
hold-down nut recess. Inspect inside of cylinder
barrel for dents and scoring, for corrosion as indicated by rust and pitting, and for ring wear as evidenced by a ridge near the top and bottom of the
barrel. Also check inside of barrel for out-of-round
and taper, using a dial indicator.
c. Spark Plug Inserts and Pins - Examine for
crossed or otherwise damaged threads and looseness
of insert in head.
d., Rocker Shaft Bosses - Examine rocker shaft
bosses for oversize and galling of bearing surfaces.
e. Valve Seat Inserts - Examine for signs of erosion ,
burning, pitting or warping.
f. Valve Guides - Examine for wear and looseness.
If loose in cylinder head, or if excessive clearance is
found between valve stem and guide, replace.
g. Rocker Boxes - Examine for cracks and smoothness of finished surfaces.
h. Intake and Exhaust Flanges - Examine for nicks
and burr s and smoothness of surfaces. Check studs
for being straight and tight.
(3) Valve Mechanism.
a. Inspect exhaust and intake rockers for cracks,
particularly around lubrication holes. Also inspect
rockers for straightness, nicks and condition of
bushing. Check rocker shaft for wear. See that
lubrication holes are not obstructed.
b. Examine pushrods for straightness by rolling
them on a flat plate. See that lubrication holes on
ball ends are not scored or obstructed.
c. Check valve springs for fractures, corrosion and
for proper pressure and length as specified in Table
of Limits. Inspect ends of each spring for splitting
and cracks.
d. Inspect valve spring retainers and seats for
cracks and wear.
e. Inspect valve spring retainer locks for wear and
galling on outside diameter and for wear and fit on
valve stem.
f. Inspect exhaust valves carefully, using a magnifying glass and magnaflux equipment for cracks on the
end of valve stem, valve head and in grooves for retain locks. Inspect valve stem and tip for scoring,
pitting and wear. Check valve face for warpage,
pitting and burning.
g. Inspect intake valves as described in preceding
paragraph.
h. Check hydraulic lifters in accordance with
instructions given in Section 16.
(4) Oil Sump - Examine condition of sump in gener-
TABLE X. MAGNETIC PARTICLE INSPECTION
Part
*Method of
Magnetization
Crankshaft
Circular and
Longitudinal
Connecting Rod
Critical Areas
Possible
Defects
2500
Journals, fillets, oil
holes, thrust flanges,
prop flange.
Fatigue cracks,
heat cracks.
Circular and
Longitudinal
1800
All areas.
Fatigue cracks.
Camshaft
Circular and
Longitudinal
1500
Lobes, journals.
Heat Cracks.
Piston Pin
Circular and
Longitudinal
1000
Shear planes, ends,
center.
Fatigue cracks.
Rocker Arms
Circular and
Longitudinal
800
Pads, socket under
side arms and boss.
Fatigue cracks.
Gears over 6 Inch
Diameter
Shaft Circular Teeth
Between Heads Two
Times 90°
1000 to
1500
Teeth, Splines.
Fatigue cracks.
Shafts
Circular and
Longitudinal
1000 to
1500
Splines, Keyways,
Change of Section.
Fatigue cracks,
heat cracks.
Thru Bolts
Rod Bolts
Circular and
Longitudinal
Threads Under Head.
Fatigue cracks.
NOTE: (*)
LONGITUDINAL MAGNETISM:
CIRCULAR MAGNETISM:
24
AC or DC
Amperes
500
Current applied to solenoid coil surrounding the work.
Current passed through work or through non-magnetic conductor
bar inserted through work.
aI, checking for possible cracks or fractures. Check
drain holes and Helicoils for damage.
(5) Crankshaft and Connecting Rods.
a. Remove counterweights. Inspect all damper pins
and bushings for wear.
b. Inspect propeller bolt bushing threads.
c. Inspect all crankpins and main journals for burning, scoring, galling and excessive wear. (Refer to
Section 13 for limits.)
d. Inspect oil tubes for obstructions, and check
tightness of tubes, bushings and plugs.
e. Measure run-out of center journals and propeller
flange. (Refer to Section 13.)
f. Polish crankpins and journals. Inspect by Magnaflux with circular magnetization. If in doubt, demagnetize longitudinally. Plug oil holes before
magnetizing.
g. Inspect all connecting rods and caps for cracks,
check alignment of crankshaft bushing with piston pin
bushing. The crankshaft hole and the piston pin hole
must be parallel with each other within .001 inch per
inch of length.
(6) Pistons and Piston Pins.
a. Check piston pin plugs for smoothness, wear and
proper fit in the piston pins. Discard piston pin plugs
which are cracked or show excessive wear. If plugs
are pressed in d'iscard assembly.
b. Check piston pins carefully for cracks, using
magnaflux equipment. Also check piston pins for
scoring, flat spots, out-of-round, straightness and
for proper fit in piston. Piston pins which are
cracked, our-of-round, bent, scored, or excessively
worn must be replaced.
c. Inspect pistons visually for corrosion, cracks,
burning, scored or galled skirts and piston pin bearings. Check ring lands for cracks by applying light
side pressure. Measure skirt diameters and pin bores
for comparison with mating parts. Install new rings
of standard or proper oversize, and measure side
clearances. Also measure gaps of new ring in cylinder barrels. (Refer to Section 13 for all limits.)
(7) Crankcase Cover.
a. Inspect cover for cracks, particularly around
stud holes, by using a magnifying glass and if necessary, by etching any doubtful portions for possible
cracks. Inspect magneto mounting flanges for cracks,
corrOSion, burrs, scratches and flatness.
b. Check all studs on cover for cracks and tightness.
Stretched or loose studs must be replaced.
c. Inspect threads for oil pressure relief cap and oil
screens.
d. Inspect oil pump impeller and shaft bores in
casting, shaft bores in cover plate and plate surface
for scoring and wear.
(8) Camshaft.
a. Inspect cam lobes and journals for scoring, wear
and pitting. Inspect screw holes.
(9) Gears.
a. Check magneto, starter, generator, oil pump,
camshaft and crankshaft gears for cracks, nick;:"
burrs, wear and proper fit. Inspect camshaft gear,
crankshaft gear and magneto gears by Magnaflux for
fatigue cracks.
Section 11
REPAIR AND REPLACEMENT
1. GENERAL RE PAIR.
2. CASTINGS. Remove the raised edges of nicks and
burrs on machined surfaces with a hard Arkansas
stone. Unobstructed flat surfaces, such as cover
plates etc. may be returned to true flatness if a
lapping plate is available. Use a fine grade lapping
compound and move the part in a figure 8 motion
evenly.
3. STUD REPLACEMENT. Remove damaged whole
studs with a standard stud remover or a small pipe
wrench. Turn slowly to avoid over heating. Remove
broken studs which cannot be gripped by drilling on
center to the correct diameter for and unscrewing
them with a splined stud extractor. (Splined extractors and drills are usually sold in sets.) Examine
the coarse thread end of the damaged stud to determine its size. Standard studs have no marking. For
oversize stud identification refer to Table XI. Clean
the tapped hole with solvent and blow dry with compressed air; then examine the thread. If it is not
damaged install the next larger oversize stud. If the
old stud was maximum oversize, or if the thread is
damaged, the hole may be tapped and a helical coil
insert installed for a standard size stud. Coat the
new studs coarse thread with Alco Thread Lube if the
hole is blind or with National Oil Seal Compound if it
is a through hole that is subject to oil spray. It is
advisable to drive the new stud with a tee handle stud
driver. Turn it slowly, and compare the estimated
torque with values listed in Section 13. Drive the
stud in until it projects a distance equal to others in
the same group.
4. HELICAL COIL INSERT INSTALLATION. Helical
coil thread inserts are factory installed at various
locations. These inserts may be replaced, if damaged, with the aid of special tools procurable from any
Authorized Distributor of the "Heli - Coil" Corporation.
5. These inserts are helical coils of wire with a diamond shaped cross section forming both a male and
female thread. Drilling and tapping depths for inserts,
being installed in blind holes, should be equal to twice
the nominal diameter of the insert. The helical coil
drills and taps must be absolutely perpendicular to the
machined surface of the casting. Drilling should be
accomplished in a drill press after the casting is
firmly supported, clamped and alignment checked.
For drilling and tapping aluminum alloy castings, use
a lubricant made of one part lard oil and two parts
kerosenetoprevent overheating the metal and tearing
the thread.
25
6. To remove a damaged helical coil, use the proper
size extracting tool specified for the nominal thread
size. Tap the tool into the insert so the sharp edges
get a good "bite". Turn the tool to the left and back
the insert out. To install a new insert, blowout all
chips and liquid, slide the insert over the slotted end
of the mandrel, and engage the driving tang in the
mandrel slot. Wind the insert into the tapped hole
slowly. The outer end of the insert should lie within
the first full thread of the hole. Break off the driving
tang with long nose pliers.
7. PARTS TO BE DISCARDED.
(a) Discard washers, nuts, screws, etc. which are
bent, burred, nicked, stripped or otherwise deformed.
Discard external attaching parts if cadmium plating
is not intact.
(b) Replace any part found to be cracked unless it is
an unstressed part that can be repaired by welding
without further damage or distortion to it.
(c) Discard all gaskets, packings, oil seals, lock
washers, palnuts, elastic stop nuts, cotter pins, lock
wire and hoses.
(3) Repair cylinder bores which are slightly corroded, scored or pitted by honing. Cylinder wall
finish should be as specified in Section 13. If the
maximum allowable bore diameter, taper or out-ofroundness is exceeded, regrind and hone to clean up
at .005 inch over size if possible. If necessary, regrind and hone to .015 inch oversize. Refinished bore
must not taper over .0005 inch, with largest diameter,
if any, at bottom, and it must be parallel to finished
surface of base flange within .001 inch in its full
length.
(4) Reface valve seats which are pitted, burned or
worn by removing the least amount of metal possible.
Following the repair of valves, the valve seats may
then be lapped in with suitable valvegrinding compound.
After the valves have been ground and checked
for proper seating, remove all traces of grinding compound with an approved cleaner.
(5) Replace valve guides if loose in cylinder head or
8. REPAIR AND REPLACEMENT OF ENGINE
if excessive clearance is found between valve stem
PARTS.
and guide. If guides are scored, they should be re(a) Crankcase.
placed. Remove guides with the use of a suitable
(1) Make repairs to the crankcase in accordance
driver and an arbor press. Ream or broach to obwith instructions given in paragraph 1 of this section.
tain specified fit with valve stems.
Particular attention should be given to removing
(6) Remove and replace spark plug inserts which
nicks and burrs from all finished surfaces, using a
are loose or leaking. Remove hard carbon from
fine stone and polishing with crocus cloth.
threads in inserts with a tap, being careful not to
(b) Cylinders.
remove any metal.
(1) Replace cylinder and head assemblies which are
(7) Remove burrs, nicks and roughness from exhaust
found to have loose heads or cracks, except for small
flanges with a fine file or scraper.
cracks near the surface of the cylinder fins. Small
(8) Repair intake flanges by removing nicks with a
cracks on the end of cylinder fins should be carefully
stone. Polish flange with crocus cloth. Tighten studs
removed by filing. Round off sharp corners.
on intake flange, if necessary, and dress threads,
{2) Remove nicks on flanged surface of cylinder
using thread chaser.
barrel flanges by hand honing. Polish flanges with
crocus cloth.
TABLE XL STANDARD AND OVERSIZE STUD IDENTIFICATION
OverSize on
Pitch Dia of
Coarse Thread
(inches)
Stamped
Machined
Standard
None
~
None
XXXXXXP003
.003
~
~
RED
XXXXXXP006
.006
~
Typical
Part No.
XXXXXX
26
Optional Identification
Marks on Coarse Thread End
. "" .... =:L
A.
\\\I\\\I\\\I\~
Identification
Color
Code
BLUE
'" - . v '" '" "'''''''
XXXXXXP009
.009
(@
XXXXXXPOO7
.007
~
BLUE
XXXXXXP012
.012
@)
GREEN
~
GREEN
ASSEMBLe- 6U$HIN(,S
FLUSH WITH BOSSES
AS SHOWN
22949
60
,
I
~A
I
I
/--!~,
0.240
.
I
.•
-~,;~;"~
I
.7031.± .0005
LINE REAM BUSHING
.
~
I
VIEW AA
Figure 17. Assembling Rocker Shaft Bushings.
(9) Stone finish surfaces of rocker boxes for nicks and
scores. Polish surface with crocus cloth.
OO)lf the rocker shaft is excessively loose in the cylinder head support bosses they may be brought back to standard size by boring or reaming in line and installing repair
bushings. The center line of the enlarged boss bores must be
9.901-9.911 inches above the cylinder base flange mounting
surface, in order that the reamed bushing bores will maintain the same distance. This dimension is important, because variations in spacing of the rocker axis from the camshaft will change the mechanical clearance in deflated valve
lifter units and may make them inoperative. The minimum
boss wall thickness measured at the edge of the center boss
prior to any reaming and bushing must be 0.240 inch. The
bore surface must be 60 RJ\1S after reaming.(See Figure
pins and oil seal race. Stone any nicks on finished surfaces.
(2) If threads of any propeller bolt bushing are damaged, drive out old bushing, and draw in a replacement bushing with the rounded side of the head toward the shaft. If
damper pin bushing in shaft or counterweights are worn,
drive out or press out old bushings, and drive or press in
replacements which have been chilled. Be sure to use COtrect bushings.
(3) Plug oil holes with soluble grease or fibre before
Magnaflux inspection. Remove plugs after inspection. Remove Hubbard plug before inspection. Install new plug
after inspection (except C145-2H shafts).
(4) Excessively worn shafts must be reground to .010
inch undersize and re-nitrided.
(a) Excessive localized brinelling of the crankshaft
dampener pin bushings can affect propeller blade tip stresses. It is, therefore, recommended that at each major overhaul the pin bushings be inspected and replaced as required.
Only the crankshaft blade bushings are available in oversize.
(b) Inspect in the following Manner :V1easure the inside
diameter of the bushing across points A,B and C. Take the
average of A and B and deduct this from C. If the difference exceeds 0.001 inch, the bushing or counterweight
should be replaced.
B
c
17.)
(c) Valve Mechanism.
( 1) Remove nicks and scores from exhaust and intake
rockers and polish finished surfaces with crocus cloth.
(2) Polish valve rocker bushings for slight scores and
roughness.
(3) Straighten push rods which are slightly bent by tapping into proper shape, using a light mallet. Polish ball ends
with crocus cloth. Loose or badly worn ball ends must be
replaced by complete pushrod assembly.
(4) Valve springs which are broken at flat ends cannot
be repaired satisfactorily and, therefore, should be replaced.
(5) Remove scores or burrs from valve spring seats by
stoning and polishing.
(6) Polish valve spring seat locks with crocus cloth inside and outside diameter.
(7) Stone valves to remove burrs and scores in the lock
grooves and on stem tips. If tips are worn, they should be
dressed with a fine emery wheel to secure a flat surface,
square with valve stem. Replace warped or badly pitted
valves. Use a standard valve refacing machine for conditioning valve contact faces and lap into valve seats.
(d) Crankshaft and Connecting Rods.
(1) Before Magnaflux inspection, polish journals, crank-
B
Figure 18. Measurement of Dampener Bushing.
1.
2.
3.
The C measurement should be the point of maxmum diameter, which is generally a point perpendicular to the lengthwise centerline of the crankshaft.
.\1easurements A and B should be taken at points
approximately 60° either side of point C.
After removing the bushings from the crankshaft
blades, measure the inside diameter of the holes.
Select a replacement bushing which will give an
interference fit of 0.001 to 0.002 inch.
(c) Replacement bushings are available in standard,
0.0015, 0.003 and 0.005 inch oversize on the outside diameter.
(d) A special tooi for removing and replacing these
bushings has been developed by Borrough's Tool and
Equipment Corporation,2429 North Burdick Street,
27
Kalamazoo, Michigan. It is recommended that this
tool only be used for these operations. Removing and
replacing bushings with makeshift tools and methods
can result in irreparable damage to the crankshaft
and/ or dampeners. Order tool direct from Borrough's
Tool and Equipment Corporation.
(5) Stone small nicks in connecting rods. Replace
bolts if damaged in any way. Replace damaged nuts.
Press out excessively· worn bushings; smooth
bores; oil new bushings, and press in with split at
45 0 from axis toward big end.
(e) Pistons and Piston Pins.
(1) Remove small scores from piston skirts with a
hard A:r kansas stone and from pin bores with crocus
cloth. Polish old type pins to obtain correct clearance and all pins to a smooth surface before Magnaflux inspection.
Do not reduce original piston surfaces.
Never use abrasive paste, wire brushes or
buffers on pistons. After repair, re-check
dimensions.
(2) Replace cracked, burned or heavily scored
pistons with new parts of proper size for cylinder
barrels. Maintain set within 1/4 oz. difference in
weight of any two pistons. Replace worn plugs in
C 125 piston pins of old type.
(3) Replace old piston rings with new standard rings
in standard barrels. Use .005" O.S. rings with
standard pistons in .005" O.S. barrels. Use .015"
O.S. pistons and rings in reground barrels.
(f) Crankcase Cover Assembly.
(1) Stone nicks and scores on finished surfaces, and
chase female threads, if necessary. Stone burrs on
oil screen and relief valve cap threads.
(2) Stone small scores and nicks on oil pump gear
teeth. Discard worn and deformed parts.
(3) Replace tachometer drive housing oil seal, and
stone burrs on housing thread.
(g) Camshaft and Hydraulic Valve Lifters.
(1) Stone light scores on cam lobes, journals and
valve lifter bodies.
(2) Replace camshaft if lobes are pitted or if lobes
or journals are excessively worn. Replace complete
hydraulic unit if any part is worn or damaged. (Refer to Section 16.)
.
Do not drop valve lifters or allow them to be
damaged by contact with other objects.
(h) Gears.
Stone light scores and nicks on all gear teeth.
Replace any gear whose to.oth profiles show excessive wear, heavy scoring or burrs.
(i) Intake Elbows and Manifolds.
Discard and replace cracked parts. Lap parting
flanges to true, flat surfaces.
(j) Pushrod Housings, Flanges, Clamps.
(1) Lap fla~ge parting surfaces flat.
28
(2) Remove dents from housings by tapping with a
soft mallet while on a suitable mandrel.
(3) Replace cracked flanges, housings, or clamps.
(k) Ignition System.
Replace all ignition cable assemblies.
(1) PROTECTIVE COATING. The manufacturer
protects all aluminum alloy castings, sheet metal and
tubing from corrosion by treating all surfaces of the
parts with "Alodine 1200" (American Paint and Chemical Company, Ambler, Pennsylvania).
(m) APPLICATION OF "ALODINE 1200". In the
event the original finish of an aluminum part has deteriorated or has been removed, the part may be
"Alodized" as described in "Alodine Manufacturer's
Technical Service Data Sheet No. AL-1200-D."
Wrought or die cast (smooth surface) parts, such as
valve rocker covers and intake tubes, are tumble
blasted prior to machining, if any, to roughen surface
before treatment. Such treatment should not be employed in overhaul work shops on parts with machined
surfaces. "Alodine " , unlike enamel or primer, will
not flake or peel off to contaminate engine lubricattng
oil. Corrosion protection can therefore be afforded
to all interior aluminum surfaces and parts. If enamel
coating is required for a part previously treated with
"Alodine", application of a primer before painting is
not necessary. "Alodizing" will be performed after
all machining and/or repair operations have been
completed. The surface color of an "Alodized" part
may vary from light gold to dark brown. When a part
is treated with "Alodine 1200", the thickness of the
film, or build-up, on the mating or bearing surfaces
is so small that the effect on dimensional tolerances
is negligible.
(n) REPAIR OF "ALODIZED" SURFACES. If
"Alodized" parts have been remachined, rubbed with
abrasives or scratched in handling so as to expose
areas of bare aluminum, the surface may be repaired
by local application of "Alodine" solution in the following steps:
(1) Clean bare area thoroughly with carbon tetrachloride. Do not, under any circumstances, use an oil
base solvent or strong alkaline cleaner.
(2) Mix a small quantity of hot water (180° F. ) with
1-1/2 to 2 ounces of "Alodine 1200" powder to form a
paste, then gradually dilute with hot water until one
gallon of solution is attained. This solution is to be
adjusted by addition of nitric acid to a PH value of
1. 5 to 1. 7.
(3) Apply solution with rubber set paint brush in such
a manner that solution flows over bare area. Allow
solution to remain on area from one to five minutes,
or until color of new film is approximately that of the
original.
(4) Flush part with clear water and dry with warm
air current. Do not air blast or rub with cloth to dry
new film area. If color is too light, repeat step "3"
until desired color is attained.
NOTE
If "Alodine" does not adhere to a metal, a
more severe cleaning method must be used,
A solution of 12 to 16 ounces of Oakite No.
61, or equal, per one gallon of water is
preferred. Apply and remove the solution
with caution, because an alkaline cleaner
ofthis type will remove any "Alodine" film
previously applied. Remove cleaning solution thoroughly, using plenty of hot water
and brushing vigorously.
be ne.cessary to apply zinc chromate primer
except to surfaces completely stripped of
"Alodine".
(0) ENAMEL COATINGS.
Ferrous parts, when
baked with gold enamel, will be baked with infra-red
equipment for 15 minutes at 275-285° F. following
application of each coat.
CAUTION
Before application of primer and enamel to
a part, carefully mask all connection joints
and mating surfaces. No primer or enamel
is permissible on interior surfaces of any
parts contacted by engine lubricating oil
after assembly.
NOTE
If a part which was originally "Alodized"
is to be refinished with enamel, it will not
Section 12
REASSEMBLY, FINAL ASSEMBLY, TIMING AND
TESTING
1. REASSEMBLY OF MAJOR SUB-ASSEMBLIES.
(a) Cylinder and Valve Assembly Procedure.
(1) Apply a light coat of oil on valve stems. From
inside of cylinders and head assembly, assemble
intake valve through intake valve guide. In the same
manner, assemble exhaust valve through exhaust
valve guide.
(2) Holding the valve stems so that head of each
valve is against valve seat, mount cylinder and head
assembly over suitable holding block on bench. Assemble intake and exhaust valve spring retainers
over valve guides.
(3) Assemble three valve springs over exhaust
valve and guide and onto the valve spring retainer.
Assemble valve spring seat over valve stem with
spring lands towards springs.
(4) Using valve spring compressor (Fig. 14), assemble valve spring seat locks in groove on valve
stem so that large diameter of locks are towards end
of valve stem.
(5) Assemble valve springs over intake valve and
guide in the same manner as described above.
(6) Assemble new rubber pushrod housing connections
and clamps on the pushrod housings, pushing them
toward the cylinder head for clearance when the
cylinders are assembled to crankcase.
(7) Install new cylinder base packing on cylinder
barrel base, using a very thin film of sealing compound on the cylinder flange on the flat surface that
will contact the crankcase.
Do not pick up cylinders by pushrod housings
as they are only pressed into the rocker box
and are easily bent. Any bending or misalignment will result in an oil leak.
(b) Connecting Rods and Crankshaft.
(1) Install new bearings inserts of standard or
undersize, as required, in rods and caps.
(2) Apply a thin coat of oil on bearings and assemble
connecting rods in their proper positions on the
crankshaft with the connecting rod numbers pointing
up (Fig. 16).
NOTE
The connecting rod bolts must be assembled on the connecting rods with the
threaded end pointed towards the piston
pin bUShing. Torque nuts to low limit - if
cotter pin will not enter increase torque
gradually up to high limit only. If cotter
pin will not enter in this range replace nut
and repeat. In no case shall nuts be torqued below low limit or over high limit.
(Refer to Section 13 for Torque Limits. )
(3) Place 5th order counterweight (with pin) on notched
crankcheek blade of Cl45 and 0-300 crankshafts. Install
two damper pins, retaining plates and snap rings. Install
snap rings with the flat or rough side to the outside. Similarly, install 6th order counterweight on opposite blade.
(c) Pistons and Piston Pins.
(1) Install all piston rings with the work "TOP"
facing head of piston. Install the slotted oil control
ring in the bottom groove, the two plain compression
rings in 2nd. and 3rd. grooves and the chrome faced
ring in the top groove.
(2) Install a piston pin assembly partially in each
piston, but clear of the rod recess.
(d) Crankcase Cover Assembly.
(1) Install oil pressure relief valve plunger, spring,
gasket, and cap into crankcase cover.
(2) Install oil pump drive gear in lower bore of
cover with square shaft end forward. Install driven
gear in upper bore with slotted shaft end to rear.
Apply oil between gear teeth and assembly pump
cover. Install four cover retaining screws and
washers. Tighten screws moderately.
(3) Test the oil pump gears for free running in the
case. If they are free from binding, tighten cap
screws and safety wire. See that safety wire is
pressed tightly against the oil pump plate to prevent
interference.
(e) Intake Manifolds and Hose Connections.
(1) Push a new hose connector on each manifold
outlet, and place 2 clamps on each hose.
(f) Crankcase Mounting Brackets.
(1) Assemble the four crankcase mounting brackets
with Lord bushings onto mounting flange studs of
29
crankcase. Secure with 3/8 plain washers, lock
washers and nuts.
2. FINAL ASSEMBLY PROCEDURE.
(a) Prelimi.nary.
(1) Mount the 2-4-6 case half, with parting flange
up, on a suitable engine stand which will permit tilting
the crankcase to horizontal and upright positions. Lay
the 1-3-5 case half on the bench, with parting flange
up. Spread a thin continuous film of No. 3 Aviation
Permatex on the left crankcase parting flange. Take
care that the Permatex does not get on any other part.
Lay lengths of No. 50 silk thread on parting flange.
Thread should be on inSide of bolt holes but never on
the flange edge. Coat the oil seal recess of each
casting with light weight Tite-Seal or an equivalent
gasket paste.
(2) Dip valve lifter bodies in light oil and install
each in its original case guide. (Fig. 19.) Push a
used pushrod housing connector over the outer end of
each lifter in the 1-3-5 side to retain them when the
casting is inverted.
(3) Install a new insert, of proper size for the
crankshaft journals, in each main bearing boss.
Tangs must engage case notches and insert ends
should project very Slightly.
Figure 19. Installing Cam Follower
Body in Crankcase.
(4) Install the starter pinion pivot over the dowel in
the 1-3-5 side recess. (See Fig. 21.)
. (5) Oil camshaft bearing surfaces in crankcases and
lay camshaft in the cam bearings of No.2 -4-6
crankcase. Check camshaft for end clearance in
accordance with limits as set forth in the Table of
Limits.
(b) Installing Crankshaft and Connecting Rods.
(1) Oil bearings thoroughly. Lay crankshaft and
connecting rod assembly in the 2 -4-6 side bearings.
Avoid striking through studs, and guide lower rods
through cylinder ports. (See Fig. 22.)
(2) Insert the plain bronze thrust washer half at each
end of the front main bearing, and rotate to lower
side. Place the pinned half washers against shaft
flanges, and rotate the pairs until pins lie within case
notches. Lubricate washers, (See Fig. 20.)
30
Figure 20. Installing Crankshaft Thrust Washer.
(3) Check crankshaft end clearance between either
washer and shaft flange.
(c) Assembly of Crankcase.
(1) Remove spring from new crankshaft oil seal.
Twist seal, and pass it over the shaft race behind the
prope~ler flange, with lip to rear. Coat seal lip and
shaft race with Gredag #44. Pass the spring around
the shaft, and hook the ends. Lift the spring progressively into the seal groove. Lift the crankshaft
slightly, and push the seal into the recess. The split
must be 20 0 from the parting surface on the upper
side of the case.
(2) Invert the 1-3-5 case half, and place it on the
2-4-6 half, guiding the through stud (or studs) through
the oppOSite holes and the upper connecting rods
through cylinder ports. (See Fig. 23 .) Install new
"0" rings in grooves of through bolts before assembling case halves, and install proper new "0" rings in
through bolt grooves before inserting the bolts. Insert the seven long and two short through bolts. Check
fit of pivqt and seating of castings.
(3) Install the four 3/8-inch through bolts through
the bottom of the case. Install lifting eye, spacers,
waShers, screws and nuts in 4th and 5th holes from
rear of upper flange. Install other flange screws,
and tighten nuts securely. Install spacers, lockwashers and nuts on ends of two short front through
bolts, on left end of upper front long through bolt and
on ends of rear through bolts. Tighten bottom through
bolt nuts. Tighten slotted nuts of short tie bolts only,
and install cotter pins •
(4) Attach 1-3-5 side mount brackets to stand. Install the breather elbow. Place crankcase in upright
position.
(d) Installing Gear, Crankcase Cover and Sump
(1) Rotate crankshaft to place No.1 piston on T.D.C.
(2) Assemble crankshaft gear with timing mark facing camshaft. Secure with four 1/4-inch cap screws,
screwed down finger -tight.
NOTE
The holes in the crankshaft gear and camshaft
gear are so spaced that it is impossible to
assemble the gears to the shafts incorrectly.
(3) Turn camshaft so that the unthreaded ,hole is
pointing toward one o'clock. Assemble cam gear to
camshaft so that the timing mark on the cam gear
teeth meshes between the two timing marks on the
crankshaft gear. The timing mark may appear as a
chisel mark on the inner rim area or as a circular
punch impression on the end of the teeth as shown in
Figure 24. Secure with four 1/4 inch cap screws.
Place a screwdriver in one of the lightening holes in
the cam gear and rotate gear until screwdriver is
blocked against the crankcase, preventing gears from
turning when cap screws are tightened. If the cam
gear does not have lightening holes utilize other suitable means, such as a proper wedge between the teeth
of the crankshaft and cam gears to prevent the gears
from rotating when the cap screws are tightened. Be
sure the wedge does not damage teeth of the gears.
Use a standard 7/16 inch socketwhentightening. (Fig.
24. )
(4) Remove screwdriver or wedge from cam gear
and check backlash of gears.
(5) Safety wire cap screws on both gears. Care
must be taken to press wire tightly against the gear
body to avoid any possibility of interference with the
screws of the oil pump cover.
(6) Rotate engine stand 180 degrees, place oil sump
gasket over studs at bottom of crankcase, assemble
oil sump using plain 1/4-inch washers, lock washers
and nuts, turn nuts down finger -tight.
Figure 21. Installation of starter Pinion Pivot.
Figure 22. Installation of Crankshaft and Connecting Rods.
31
(7) Place crankcase cover gasket over end of crankcase and mounting studs. Assemb1e' crankcase
cover assembly over gasket and studs. (Fig. 25)
properly meshing the oil pump drive gear into the
cam gear. Install six washers, lock washers and nuts
to studs. Install 3 washers, lock washers and cap
Screws through gear cover into oil sump (5 in new
type cover).
(8) Tighten crankcase cover retaining nuts first.
Then tighten 3 (or 5) cover -to -sump screws fully.
Tighten sump retaining nuts, starting at front. Release cover screws while rear nuts are tightened.
(9) Install the two oil screens in crankcase cover
using new gasket between screens and cover. Tighten
oil screens and secure with safety wire to the cap
screws, holding crankcase cover to oil sump. Use
safety wire between center crankcase cover cap
Screw and oil sump drain plug. Safety wire oil pressure relief valve cap to nearest stud holding crankcase cover to crankcase.
(e) Installing Hydraulic Units and Pushrod Housing
Flanges.
(1) Rotate engine stand so that crankcase is in
flight position. Oil hydraulic units with thin coat of
light oil.
NOTE
Be sure that the hydraulic unit is working
properly and smoothly by depressing the piston with the thumb several times. Units
should be deflated of trapped air and oil by
releasing the ball check. Insert a 3/32 -inch
diameter rod in tube of unit (rod should have a
dull end) so as to lift ball check from seat
while piston is being depressed.
(2) Insert hydraulic units, tube end first, into the
cam follower body. Insert tappet cups (flat side toward hydraulic unit) on top of hydraulic units in the
cam follower body.
(3) Place pushrod housing flange gaskets over studs
on housing pads in crankcase. Install push rod housing flanges over studs and gaskets.
(4) Secure flanges to crankcase with washers, lock
washers and nuts. Tighten middle nut of flange first.
Do not tighten nuts excessively, as the flange may be
cracked or gasket damaged.
(f) Installing Cylinders.
(1) Coat inside of cylinder barrels generously with
a light oil.
Figure 23. Installation of Crankcase 1-3-5 Over Crankcase 2-4-6.
32
Figure 24. Installation of Gears in Crankcase
(2) Before installing each cylinder, coat its piston pin
and connecting rod bushing with light oil. Place the crankpin at T.D.C., and install the piston with number forward.
Coat the piston with the same oil.
(3) Stagger gaps in piston rings on the piston so that
they are evenly distributed around the piston to prevent
blow-by.
(4) With one hand compressing the steel clamping band
around the rings, assemble the cylinder barrel over the top
of the piston (Fig. 26.)
Do not pick up cylinder by push rod housings.
Make sure piston pin plugs are in place.
(5) Steady the cylinder, pushing it carefully back to the
mounting studs, moving the steel band back on the piston.
Remove steel band when cylinder is pushed on the full
length of the piston.
(6) Assemble cylinder flange over studs on crankcase.
Be sure that cylinder base packing is properly in place and
not twisted. Assemble nuts on studs and tighten slowly and
evenly. See Table of Limits for the proper amount of torque to be applied on nuts.
(7) Rotate crankshaft to a position where exhaust and
intake valve would be closed. Insert pushrods into housings,
hold rocker arms in place and push in the rocker arm shaft.
Be certain that the rocker arm with the oil squirt hole at
the top of the foot is in the exhaust position and the rocker
arm without the oil squirt hole is in the intake position.
(11 )Test crankshaft for free rotation.
(g) Installing Air Intake System.
(1) Place gaskets on cylinder intake flanges. Attach .intake elbows on the two studs on the flange, and secure with
washers, lock washers and nuts.
(2) Place gasket on intake mount pad of oil sump and
install intake manifold securing with washers, lock washers
and cap screws.
(3) Push hose connections over ends of intake manifold
and· intake elbows. Install clamps on both ends of each
connection and tighten securely.
(4) Place gasket over four studs at carburetor, mounting
flange at bottom of oil sump. Assemble carburetor to
mounting flange at bottom of oil sump. Secure with four
washers, castle nuts and safety wire.
(h) Installing Ignition System.
(1) Assemble lower spark plugs with gasket in each cylinder.
(2) Determine the firing position of cylinder No.1 in
the following manner~
a. To determine that the piston is on the compression
stroke, place thumb over upper spark plug hole on No.1
cylinder and tum crankshaft in the direction of rotation.
The intensity of the pressure will indicate that the piston is
on the compression stroke. The top center (TC) mark
stamped on the propeller flange edge will align with the
crankcase split below the crankshaft when No.1 piston is at
top dead center. Other flange marks indicate angles from
24 0 to 32 0 before top center. Use a flat metal indicator or
square to align the marks with the split.
b. Tap the crankshaft forward to the firing angle
specified in Section 1 for the model and magneto to be installed.
(3) Installing and Timing Magneto to the engine.
a. Before installing magnetos, be sure they have been
correctly timed and checked in accordance with Section 15.
'It
NOTE
Check to make sure ball cup is properly installed in
tappet body before inserting push rods.
(8) Assemble gaskets on rocker box flanges and install
valve rocker box covers and secure with lock washers
and fillister screws.
(9) Slip pushrod connections and clamps down over
pushrod housing flange.
(10)Assemble the remaining cylinders in the same manner as described above.
Figure 25. Installation of Cover to Crankcase.
33
b. Rotate the magneto drive gear, attached to the
magneto, until the timing marks on the chamfered
tooth of gear and timing pOinter are opposite each
other as seen through the timing window in the magneto cover. At this position the breaker contacts
should begin to open.
c. All adjustments for exact timing are made at the
drive end and not by altering the position of the
contact points. See that the mounting faces are clean
and smooth, place gasket on mounting flange and with
the timing marks (as described in b. above) opposite
each other, install the magneto on the engine and
secure with its mounting nuts. Exact timing is obtained by turning the magneto through the angle provided, by the slots in the magneto flange.
d. Shift the magneto case clockwise to the limit of
the flange slots. The breaker points should be closed.
e. Insert a .0015-inch feeler between breaker points
and tap mounting flange in a counterclockwise direction until the exact point of release is obtained.
NOTE
If a Bendix No. 11-851 timing light or its equivalent
is available, it should be used to determine the
opening of the contact points rather than using a
feeler gage. The use of shim stock or cellophane
strips invariably introduces a possibility of fouling
the points, since oil and dirt is nearly always present
on such feeler strips.
f. To
check timing tighten magneto retaining nuts; back up crankshaft about 10 0 • Insert feeler
or watch light, and tap shaft forward until breaker
pOints open. Check crankshaft angle.
NOTE
If timing light is used, rotate engine back-
wards until light comes on, then tap crankshaft
forward until points break and light goes out.
g. Install other magneto on the engine following the
same procedure outlined above.
h. Remove timing eqUipment from engine.
i. Before installing ignition cables, refer to Fig. 10, 11, or
12 and check connections from magneto terminals to spark
plugs by position and length of wires. Radio shielded cable
assemblies should be new, complete assemblies. For Bendix
S6LN-21 magnetos, cable assemblies are sold complete
with magneto outlet plates, ready to install. Complete cable
assemblies for Bendix SF6LN-I2 magnetos are still
supplied. They are complete with proper terminals and
cable brackets.
NOTE
It is recommended that
all ignition cable
brackets designed for attachment to cylinder
base studs be removed from service. New
cable assemblies are equipped with brackets
to be attached, over spacers, to 3rd and 6th
holes from rear of upper crankcase flange
with 1-5/8-inch screws.
(1) Install spark plugs after spreading a film of BG
mica thread lubricant on their 18 mm. threads.
Tighten to speCified torque.
(2) Install cable brackets on crankcase flange and on
crankcase cover studs. Then install unshielded spark
plug safety terminals or shielded terminal sleeves
union nuts. Install terminals or outlet plates in
magnetos.
(3) ENGINE RUN-IN AND TEST PROCEDURE
AFTER MAJOR OR TOP OVERHAUL.
The purpose of "running-in" re-assembled engines is to permit initial lubrication and seating of
new parts at relatively low speeds and temperatures.
The run-in period also serves as a test of operation
of all components. For this reason all instruments
must be watched closely throughout the test so that
the engine may be stopped at the first indication of
trouble. It must be emphasized that subsequent
maintenance and operation of the engine is likely to
be adversely affected by careless run-in procedure.
Figure 26. Installing Cylinder on Crankcase.
34
Air cooled engines depend on a rapid flow of
cool air through cylinder fins to maintain cylinder temperature within the specified limit.
The air must actually pass through the fins to
do its job. Special baffling and a scoop may
be necessary on test stands. Cylinder head
and oil temperatures must be recorded and
observed continuously. At no time may the
limits specified in Section 1 be exceeded
without damage.
The best run-in results are obtained by the use of
a suitable test stand, test propeller and test cell
equipped with adequate instrumentation. But when
these facilities are not available and the engine is to
be run -in while installed on the airplane, all cowling
and baffling should be removed, the engine headed
into the wind and a 4-bladed Test Club type propeller
used. A flight propeller is not designed for extended periods of ground or test operation.
To assure that the specified maximum cylinder
temperature will not be exceeded: Install a spark
plug gasket type thermocouple in place of the regular
gasket under the down-stream spark plug of the
hottest cylinder. Locate the cylinder by experiment.
Use the most accurate cylinder temperature gauge
obtainable. Check accuracy of oil temperature and
pressure gauges frequently. A fuel flow meter or
weighing device will be necessary in order to determine fuel consumption accurately enough to check
carburetor performance.
The following schedule should be followed whenever wearing parts are replaced and always after
major or top overhauls.
TABLE XlI. TEST OPERATING LJMITS
Feature
Maximum Take-Off Power
Maximum Continuous Power
Full Throttle Speed RPM .
Idle RPM and Tolerance .
Fuel Grade Octane. . . .
Fuel Consumption at Full
Throttle (#/Hr.) . . • . .
Fuel Pressure (psi) Inlet - Carburetor
Max. Allowable
..... .
Min.. Allowable . . . . . . .
Recommended Flight Minimum.
Engine Intake Air Temperature .
Manifold Vacuum at Full Throttle
Manifold Vacuum at Idle
Oil Grade
Above 40° F • . . • . •
Below 40° F • . . • . • •
Oil Consumption at Maximum.
Oil Temperature (Desired Range) .
Oil Temperature Maximum. • . .
Oil Pressure at Full Throttle (psi max. )
(Oil Temp. 175° to 185° F.) .
Oil Pressure at Idle (psi min. )
(Oil Temp. 140° to 150° F.) .
Timing of Engine & Tolerance
Right . . • . . . . . . . .
Left • • . . • . . . • . .
Magneto Drop at Full Throttle.
Cylinder Head Temperature at lower spark plug.
thermocouple
Crankcase Pressure. • • • . • • . . • . • .
*
C-125
125-2550
125-2550
· 2550-2650
500±25 RPM
.80(87 or lOOLL
63-68 lbs.
C-145
0-300
145-2700
145-2700
2700-2750
500-~5 RPM
80(87 or lOOLL
145-2700
145-2700
2700-2750
500±25 RPM
80(87 or 100 LL
71. 5/76. 5
71.5/76.5
Ambient
1. 0-1. 8" Hg.
· 17.0" Hg. Min.
6
.4
.4
Ambient
1. 5-2. 5" Hg.
15. 0"to17. O"Hg.
6
.4
.4
Ambient
1. 5-2. 5" Hg.
15. 0"to17. O"Hg.
2.2 lbs. Hr.
· 150-200° F.
225° F.
40-50
20-30
. 95 lbs. 1/2 Hr.
150-200° F.
225° F.
40-50
20-30
.95 lbs. 1/2 Hr .
150-200° F.
225 F.
35-50 psi
10 psi
28"±1 ° BTC
30°:!:1° BTC
75 RPM
550° F. Max.
35-50 psi
5 psi
26"±1° BTC
28°:!:1° BTC
100 RPM
525° F. Max.
1. 0" H20 Max.
1. 0" H20 Max.
Ref. (For Trouble Ref (For Trouble
Shooting Only)
Shooting Only)
0
35-50 psi
5 psi
26"±1° BTC
28°:!:1° BTC
100 RPM Max.
525° F. Max.
1. 0" H20 Max.
Ref (For Trouble
Shooting Only)
Any sudden increase in crankcase pressure and rapid fluctuation of manometer usually indicates sticking
of rings.
Before removing cylinders check crankcase breather and manometer.
35
TABLE XIII. STANDARD ACCEPTANCE TEST
Run No.
Time-Minutes
RPM
5
1200
2450
3
5
5
4
10
Rated RPM (Adjust engine-fuel flow, pro etc.) (Reduce RPM for
adjustments)
5
10
Engine Parameters checks (fuel system, oil pressure, temp. etc. see applicable data) 2100 mag check. See Note A.
6
5
Idle RPM (Cooling period - 300 0 max C. H.T. Before shut-down.
2
1600
Stop engine, drain oil, weight oil in for oil consumption determination.
7
5
8
30
9
5
Warm-up to rated RPM (minimum 1200 RPM)
2450 (See Note B)
500
+
25 Idle (cooling period - 300 0 max C.H.T. before shut-down)
Stop engine, drain and weigh oil. See Note C.
A.
Magneto drop and spread to be taken during run No.5. Engine must be throttled to specified RPM and temperature
allowed to settle out before taking magneto drop and spread.
B.
Readings must be recorded after completion of each 10 minute interval during oil consumption run.
C.
Oil consumption at a rate of 1.25 Ibs/40 minute run maximum is acceptable. If oil consumption is excessive, determine
cause and correct.
36
NOTES
37
NOTES
38
Section 13
TABLE OF LIMITS
Fig.
No.
27
27
Ref.
No.
1
2
28
28
3
28
5
28
28
28
28
28
28
28
28
28
28
28
6
7
8
9
10
11
12
13
13A
13B
l3C
4
New Parts
Min.
Max.
Description
CRANKCASE
Dia:
•
•
Valve lifter guide
Dia:
Cylinder in crankcase bore .
Dia:
Prop. Hyd. valve in crankcase
Dia:
Tie bolts in crankcase ••
•
Dia:
Starter pinion pivot in crankcase.
Dia:
Starter bushing in crankcase •
Dia:
Crankshaft main bearing bore.
CRANKSHAFT
Run-out at center journals (shaft supported at
front and rear journals) • • • . . •
Run-out near edge of propeller flange
Dia:
Main journals • • • • • • .
Dia:
Crankpins..
• ••.•.•
Crankpins and journals • • • •
• Out of round:
Bushings in propeller flange. .
Dia:
· .•
Bushings in crank cheek blades
• • • • Dia:
side clearance:
Counterweights on crankcheek blades
Bushings in counterweights .
Dia:
Damper p i n . .
.
.Dia:
Damper pin. ••
•••
.
•
• . Length:
Damper pin in counterweight.
.
· end clearance:
Damper pin bushing bore in crankcheek
(5th o r d e r ) .
.
Dia:
Damper pin bushing bore in crankcheek
(6th order) •
.
.
•
.
Dia:
Damper pin bushing bore in counterweight
(5th order)
•••.
Dia:
Damper pin bushing bore in counterweight
(6th order)
...• •
. • ••
Dia:
Crankshaft in front bearing . . .
. . • end clearance:
Crankshaft in main bearings.
• . • • ••
Dia:
.002 L
.012 L
.003 L
.001 L
.001 L
.0005L
2.438
.0035L
.012 L
.0045L
.000
.000
2.247
1. 936
.000
.0003T
.0015T
.004
.0015T
.3758
.780
.001 L
.015
.005
2.248
1. 937
.0005
.0021T
.003 T
.012
.003 T
.3768
.785
.023 L
.015
.005
2.2445*
1. 9335*
.001
.016
.040 L
.4643
t
435
.438
t
.4613
.4643
t
.435
.005 L
.001 L
.438
.015 L
.004 L
.Dia:
.Dia:
.Dia:
.000
.0005L
.002 T
.0014L
.001
.003 L
.0045T
.0021L
.004 L
.001 L
.004
.003 L
.008
.005 L
.012
14
15
27
16
27
27
27
17
18
19
CONNECTING RODS
Bearing and bushing - twist or convergence per
inch of bearing length.
.
•
Bearing on crankpin.
..
Bushing in connecting rod.
Piston pin in conn. rod bushing
27
28
20
21
CAMSHAFT
Camshaft in bearings.
Camshaft flanges to crankcase
•• Dia:
• end clearance:
27
22
PUSHRODS
Pushrod length
. . . . .
Pushrod length (Service only) .
. Overall:
. Overall:
27
23
Notes:
.0005L
.003 L
.001 L
.0005T
.001 T
.0015T
2.437
4613
28
28
PISTONS, RINGS, PINS
Piston - top land in cylinder bore (C-125)
Piston - top land in cylinder bore (C-145,
0-300-A, B, C, D, E) . • . . . . . . . .
Piston - 2nd, 3rd and 4th land in cylinder
bore (C-125)
••.•.•
•
Service
Limit
10.797
10.827
10.827
10. 857
.Dia:
.034 L
.038 L
.Dia:
.038 L
.042 L
.Dia:
.030 L
.034 L
t
.025 L
.006 L
.001
.006 L
10.785
(*) If crankshaft is worn beyond these limits, regrind journals and crankpins to • 010 in. undersize and
re- nitride.
(t) If bushing in either counterweight or crankshaft blades are brinelled in excess of 0.001 inch, the
bushings should be replaced. (See Section 11, page 27.)
39
TABLE OF LIMITS (Cont. )
Fig.
No.
Ref.
No.
27
24
27
25
27
27
27
27
26
27
28
29
27
30
27
31
27
27
27
27
27
27
27
27
27
32
35
36
36A
37
38
40
41
42
27
27
27
27
42A
43
44
45
Notes:
40
New Parts
Min.
Max.
Description
Piston - 2nd and 3rd lands in cylinder
bore (C-145, 0-300-A, B, C, D, E).
Dia:
Piston - top in skirt in cylinder bore (C-125)
Dia:
Piston - top of skirt in cylinder bore
Dia:
(C-145, 0-300-A, B, C, D, E) . . . . . . . . . .
Piston - bottom of skirt in cylinder bore (C-125).
Dia:
Piston - bottom of skirt in cylinder bore
Dia:
(C-145, 0-300-A, B, C, D, E) .
Pin in Piston.
••••.•
Dia:
Deleted
Pin Assembly in cylinder
•
end clearance:
Top piston ring in groove (C-125).
side clearance:
Top piston ring in groove (C-145,
0-300-A,B,C,D,E).
.
side clearance:
Second piston ring in groove (C-125)
side clearance:
Second piston ring in groove (C-145,
0-300-A, B, C, D, E).
.
side clearance:
side clearance:
Third piston ring in groove (C-125).
Third piston ring in groove (C-145,
0-300-A, B, C, D, E).
side clearance:
Fourth piston ring in groove (C-125,
C-145, 0-300-A, B, C, D, E)
•
side clearance:
Top ring in cylinder (C-125).
Gap:
Top ring in cylinder (C-145, 0-300-A, B, C, D, E)
Gap:
Second ring in cylinder (C-125, C-145,
Gap:
0-300-A, B, C, D, E). •
Third ring in cylinder (C-125, C-145,
Gap:
0-300-A, B, C, D, E).
Fourth ring in cylinder (C-125)
Gap:
Fourth ring in cylinder (C-145,
Gap:
0-300-A, B, C, D, E).
Ring (compression ring).
Tension:
Ring (4th - oil control)
.
Tension:
CYLINDERS AND VALVES
Valve seat to valve guide axis .
Angle:
Dia:
Valve guides in cylinder head
Cylinder bore (standard)
• Dia:
Cylinder bore (0.015 oversize).
.
· Dia:
Cylinder bore roughness (in micro-inches)
· RMS:
Cylinder bore taper and out of roundness .
Rocker shaft in cylinder head boss.
• Dia:
Rocker shaft in rocker bushing .
Dia:
Rocker bushing in rocker .
•
• Dia:
Rocker in cylinder head bosses • . • • side clearance:
Rocker arm and valve spring retainer
• clearance:
Exhaust valve in guide .
• • Dia:
Intake valve in guide . .
•
Dia:
Valve face to stem axis. • • • •
Angle:
Valve stem to rocker
Exhaust valve face ............... .
Width:
Intake valve face ................. .
Width:
· ..
Service
Limit
.034 L
.009 L
.038 L
.013 L
.043 L
.016 L
.012 L
.007 L
.015 L
.010 L
.018 L
.013 L
.009 L
.OOOIL
.012 L
.0007L
.015 L
.0015L
.010 L
.005 L
.032 L
.0065L
.080 L
.009 L
.006 L
.003 L
.008 L
.005 L
.010 L
.007 L
.0045L
.003 L
.0065L
.005 L
.009 L
.007 L
.005 L
.007 L
.009 L
.002 L
.018
.023
.004 L
.035
.040
.006 L
.040 %
.045 %
.013
.030
.035
%
.013
.013
.030
.025
.035
.035
%
.030
12 lbs.
15 lbs.
.035
8 lbs.
10 lbs.
45°
.003 T
4.064
4.079
45
.001
.0017L
.0025L
.004 T
.011
4.069 +
4.084
30 Min.
.002 +
.007 L
.004 L
.013
9 lbs.
11lbs.
45°
.001 T
4.062
4.077
35
.000
.0002L
.001 L
.002 T
.004
.020
.003 L
.001 L
45° 45'
.030
.1536
.1336
.0045L
.003 L
46° 15'
.110
.1602
.1478
%
%
.016
.008 L
.005 L
(%) If necessary use. 005" oversize rings to maintain specified limits in cylinder bore to Service Limit.
(+) If cylinder is worn beyond these limits grind to • 015 in. O. S.
TABLE OF LIMITS (Cont.)
Fig.
No.
Ref.
No.
28
28
46
47
28
48
28
28
28
49
50
51
New Parts
Min.
Max.
Description
CRANKCASE COVER
•••
Oil pump gears in housing . .
Oil pump gear shafts in cover •
•.
Magneto pilot in cover
•
•••••
Starter pilot in cover (C-125, C-145 &
0-300-A, B, C). •
••• • •
Genrator pilot in cover.
••••••
Oil seal in tachometer drive housing. • • • •
Crankshaft gear on shaft (C-125, C-145 &
0-300-A, B, C). • . • • • . • • . • • •
Crankshaft gear on shaft (O-300-D, E) . •
Dia:
Dia:
Dia:
.003 L
.0015L
.001 L
,006 L
.003 L
.005 L
Dia:
Dia:
Dia:
.0005L
.001 L
.001 T
.006 L
.005 L
.008 T
Dia:
Dia:
.002 L
.000
.0005T
.0025T
GEAR TEETH BACKLASH
29
29
29
52
53
54
29
29
55
56
27
27
28
28
28
28
28
29
T1
T2
T3
T4
T4
T5
T6
T7
Crankshaft gear to camshaft gear
Magneto drive gear to camshaft gear
Starter gear to crankshaft gear (C-125, C-145,
0-300-A, B & C)
Generator drive gear to camshaft gear
Oil pump gears
Size
Nut
Nut
Nut
Nut
Nut
Nut
Nut
Bolt
1/4-28
3/8-24
5/16-24
3/8-24
7/16-20
7/16-20
3/8-24
1/4-28
PI
P2
P3
P4
Spring
Spring
Spring
Spring
-
Replacement
.013
.019
.029
.010
.014
.043
.014
.022
.050 ++
.019
.025
Torque (in. lbs.)
SPRING PRESSURES
27
27
27
29
Max.
.009
.014
Crankcase flange bolts
Connecting rod bolts #
Generator shaft
Cylinder base studs
Cylinder base studs
Crankcase tie bolts and stud
Crankcase tie bolts
Gears to crankshaft and camshaft
Part No.
Valve inner
24031
Valve intermediate 24029
Valve outer
625958
Oil pressure
relief valve
631706
.008 L
.0045L
Min.
.006
.012
TORQUE LIMITS
Location
Part
Service
Limit
100
400
175
410
490
490
370
140
Lbs.
Min.
-
125
475
200
430
510
510
390
160
Wire Dia.
Compress
to
.091 In.
.111 In.
.148 In.
1. 075 In.
1. 137 In.
1. 168 In.
27
40
77
30
44
83
24
37
74
.041 In.
1. 56 In.
6. 06
6.31
5.75
Lbs.
Max.
Used
Min. Lbs.
Notes: (#) TORQUE TO LOW LIMIT -- IF COTTER PIN WILL NOT ENTER INCREASE TORQUE GRADUALLY
UP TO HIGH LIMIT ONLY. IF COTTER PIN WILL NOT ENTER IN THIS RANGE REPLACE NUT
AND REPEAT. IN NO CASE SHALL NUTS BE TORQUED BELOW LOW LIMIT OR OVER HIGH
LIMIT.
<++) For models 0-300-D & E see Table of Limits in Section 20, page 61.
41
;:;:;:;:;:;:;:;:; PRESSURE OIL
~
DRAINOIL
SECTION A-A
SECTION B-B
Figure 27.
42
Lubrication Chart, Lateral Section Front View.
6
14
51
47
;:;:;:;:;:;:; PRESSURE OIL
~ DRAIN OIL
Figure 28.
Lubrication Chart, Longitudinal Sectional View
(Schematically shown)
43
SECTION THROUGH OIL
PRESSURE RELIEF VALVE
T7
SECTION THROUGH HIGH AND
LOW PRESSURE 01 L SCREENS
55
~~~t~\f~~
PRESSURE OIL
~ SCAVENGER OIL
~DRAIN OIL
Figure 29.
44
Lubrication Chart, Accessory Cover Section.
Section 14
INSTALLATION, OPERATION
AND MAINTENANCE INSTRUCTIONS
CARBURETOR - MARVEL-SCHEBLER
MA - 3SPA
Figure 30. Right Side View.
Figure 31. Left Side View.
CARBURETOR DATA
Engine Models . . . .
Continental Part No's .
Marvel-Schebler Part No's.
Venturi Size's . . . . . .
. C-125 .
. 40366.
10-2848.
1-5/8" .
a. INSTALLATION.
The carburetor should be mounted on the engine
with the throttle arm on the right. The throttle lever
clamp screw should be installed with a torque value of
20-28 in. jIbs., or as instructed on Marvel-Schebler
drawing No. 284-190. The carburetor is provided
with a 1/4-inch pipe tap hole for the fuel inlet line
connection. The fuel system should be so arranged
that the head of gasoline in the tank under extreme
climb conditions does not fall below two (2) inches,
The head required to flood the carburetor is forty-two
(42) to fifty (50) inches and provisions should be made
not to exceed this pressure head when the airplane is
in the nose down or steep glide pOSition.
b. CONSTRUCTION.
The carburetor is made up of two major units
- a cast aluminum throttle body and bowl cover, and
a cast aluminum fuel bowl and air entrance.
c. OPERATION.
(1) Idle System (4, Fig. 32.)
With the throttle fly slightly open to permit idling,
. C-145, 0-300-A, B, C, D, E
.628945
10-4439
1-5/8"
the suction or vacuum above the throttle on the manifold side is very high. Very little air passes through
the venturi at this time, and hence with very low
suction on the main nozzle, it does not discharge
fuel. The high suction beyond the throttle, however,
causes the idle system to function, as the primary
idle delivery delivers into the high suction zone above
the throttle. Fuel from the fuel bowl passes through
the metering sleeve fuel channel and power jet, and
into the main nozzle bore where it passes through the
idle supply opening in m:l.in nozzle through the idle
fuel orifice in idle tube where it is mixed with air
which is allowed to enter idle tube through the primary idle air vent. The resultant rich emulsion of
fuel and air passes upward through the idle emulsion
channel where it is finally drawn into the throttle
barrel through the primary idle delivery opening,
subject to regulation of the idle adjusting needle,
where a small amount of air paSSing the throttle fly
mixes with it, forming a combustible mixture for
idling the engine. The idle adjusting needle controls
45
CARBURETER PUMP DISCHARGE
CHECK VALVE
. MAXIM M
CARBL.!'ETER PU,"", DISCHARGE
H CK VALvE SPRING
CARBURETER PUMP DISCHARGE
K VA
AT
CARBVRETER PUMP DISCHARGt
H
K
A
A
'Y
PUMP INLET SCREEN
PUMP INLET SCREEN HOUSING
ACCELERATING P
PUMP INL T CH CK VA V
ACCELERATING P
PUMP FOLLOW-UP
FUEL INLET CONNECTION
AND STRAINER ASS'Y
PUMP VENT CHANNELS
THROTTLE SHAFT
FUEL BOWL
ACCE . P '"'"
I
P I
HAR
T
THROTTLE STOP SCREw
ATMOSPHERIC BOWL VENT
MIXTURE CONTROL LE VER
THROTTLE FLY
PRIMARY IDLE DELIVERY
SECONDARY IDLE DELIVERY
THROTTLE STOP
SECONDARY IDLE AIR VENT
ECONOMIZER HOLE
TERTIARY
OLE DELIVERY
IDLE NEf.DLE SEAT
TERT IARY
OLE AIR VENT
IDLE ADJUSTING NEEDL
THROTT E BARREL
IDLE EMULSION CHANNEL
MIXING CHAMBER
FLOAT VALVE AND SEAl
AIR
NT CHANN L
AIR VENT SCREEN
MAIN
VE.NTURI
NOZZLE BORE
NOZZLE OUTLET
PRIMARY VENTURI
NOZZLE
MIXTURE METERING VALVE,.
NOZZLE AIR VENT
BOWL DRAIN
NOZZLE WELL
IDLE TUBE
NOZZLE BLEED HOLES
IDLE
IDLE SUPPLY OPENINC
FUEL ORIFICE
MIXT RE MET[RING SLEEvE
P WER
THROTTLE FLY
CRUISING POSITION
FUEL CnANNEL
Figure 32. Cutaway Views of MA-3PA Carburetor.
46
JET
the quantity of rich emulsion supplied to the throttle
barrel, and therefore controls the quality of the
idle mixture. Turning the needle counterclockwise
away from its seat richens the idle mixture in the
engine, and turning the needle clockwise towards its
seat leans the idle mixture.
•
On idle, some air is drawn from the throttle
barrel below the throttle fly through the secondary
and tertiary idle delivery openings which can be considered the secondary and tertiary idle air vents
with the throttle in the slow idle position. The air
blends with the idling mixture being delivered to the
engine, subject to regulation of the idle adjusting
needle. The secondary and tertiary idle deliveries
begin to deliver idling mixture to the engine as the
throttle is opened, coming into play progressively and
blending with the primary idle delivery to prevent
the mixture from becoming too lean as the throttle
is opened and before the main nozzle starts to feed.
(2) Metering (4, Fig. 32.)
All fuel delivery on idle, and also at steady propeller speeds up to approximately 1000 R.P.M., is
from the idle system. At approximately 1000 R.P.M
the suction from the increasing amount of air now
passing through primary and secondary venturi
causes the main nozzle to start delivering, and the
idle system delivery diminishes due to lowered
suction on the idle delivery openings as the throttle
fly is opened for increasing propeller speeds, until
at approximately 1400 R.P.M. the idle delivery is
practically nil, and most of the fuel delivery from
that point on to the highest speed is from the main
nozzle. However, the fuel feed at any full throttle
operation is entirely from the main nozzle. The idle
system and the main nozzle are connected with each
other by the idle supply opening. The amount of fuel
delivered from either the idle system or main nozzle
is dependent on whether the suction is greater on the
idle system or main nozzle, the suction being governed by throttle valve position and engine load. The
main nozzle feeds at any speed if the throttle is open
sufficiently to place the engine under load, which
drops the manifold suction. Under such conditions of
low manifold suction at the throttle fly, the main
nozzle- feeds in preference to the idle system because
the suction is multiplied on the main nozzle by the
restriction of the venturi.
For fuel economy in cruiSing, a back suction
econimizer system is provided as shown in (3, Fig. 32.)
With the throttle fly in cruising position suction is
applied to the fuel bowl through economizer hole and
back suction economizer channel and jet. The section
thus applied in the fuel bowl works against the nozzle
suction applied by the venturi and therefore diminishes the fuel flow, thus giving a leaner mixture for
cruising economy.
(3) Main Nozzle (4, Fig. 32.)
The main nozzle is supplied with fuel which
passes from the fuel bowl through the metering
sleeve, fuel channel and power jet. The fuel then
passes upward through the nozzle bore where it is
mixed with air drawn from the nozzle air vent
channels and nozzle bleed holes and is then discharged from the nozzle outlet as an air and fuel emulSion,
into the mixing chamber. Air passing through the
nozzle air vent channels sweeps fuel from the nozzle
well and nozzle bore under very low suction and
therefore satisfies any sudden demand for nozzle
fuel delivery when the throttle is opened from idle
positions.
(4) Accelerating Pump (1 and 2, Figure 32. )
The accelerating pump discharges fuel only when
the throttle fly is moved towards the open position,
and provides additional fuel to keep in step with the
sudden inrush of air into the manifold when throttle is
opened. By means of an accelerating pump lever
connected to the throttle shaft, the accelerating pump
plunger is moved downward when the throttle is
opened, thus forcing fuel past the carburetor pump
discharge check valve into the Accelerating Pump
Discharge Tube which delivers accelerating fuel
through the Primary Venturi into the Mixing Chamber
of the carburetor. Upon closing the throttle, the
accelerating pump plunger moves upward, thus refilling the accelerating pump chamber by drawing fuel
from the fuel bowl through the pump inlet screen
and pump inlet check valve.
As a precaution to prevent fuel from being drawn
into the Mixing Chamber when the accelerating
pump is inoperative (any constant throttle position),
carburetor pump discharge check valve assembly
assembly mounted in the carburetor is provided with
carburetor pump discharge check valve loaded by
carburetor pump discharge check valve spring.
(5) Accelerating Pump Adjustment (5, Fig. 32.)
The Accelerating Pump Lever has three holes
into which the upper end of Accelerating Pump Link
may be fastened. The outer hole, No.3, which is
approximately midway between upper and lower holes,
gives longest stroke or maximum accelerating fuel.
The lower hole, No.1, gives the shortest stroke, or
minimum accelerating fuel, and the upper hole, No.2,
provides a medium supply of accelerating fuel. The
normal pOSition of accelerating pump is in No.2 hole,
the medium setting; however, for extremely hot
weather or high test fuels, No.1 hole may be necessary to prevent heaviness or slowness on acceleration. No.3 hole may be required in extremely cold
weather.
(6) Mixture Control (1 and 4, Fig. 32.)
The mixture control consists of mixture control
lever to which is attached the mixture metering
valve assembly. The mixture metering valve assembly is provided at its lower end with mixture
metering valve which rotates in stationary mixture
metering sleeve. Mixture metering sleeve is provided with a transverse slot through which the fuel
enters and fuel metering is accomplished by the
-relative position between one edge of the longitudinal
slot in the hollow mixture metering valve and one
edge of the slot in the mixture metering sleeve.
When mixture control lever is toward the letter "R"
on casting, a full rich mixture is provided for takeoff. To make the mixture leaner for altitude compensation move the mixture control lever away from
the letter "R" on casting toward the letter "L" on
casting. With the m:xture control lever in the full
lean position (with mixture control lever at extreme
position toward letter "L" on casting) no fuel is
allowed to enter the nozzle and idle system, thus
providing what is known as idle shut-off to prevent
accidents when working around a hot engine. This
shut-off is accomplished by the fact that the longitudinal slot in the mixture metering valve is
47
narrower than the total angular travel of the mixture
metering valve. To obta:in the full benefit of the
idle shut-off feature, with the engine idling, push the
mixture control lever to the full lean position and
allow the engine to stop from lack of fuel before
shutting off ignition, thus assuring that the cylinders
are dry of fuel.
(7) Use of Mixture Control.
When adjusting mixture control, move control in and out
slowly with the throttle at Cruising or Full Open Position
until the highest R.P. M. is attained. The carburetor
mixture will then be correctly adjusted for all throttle
positions and loads at that particular altitude.
Always have mixture control in the full rich
pOSition when coming in for a landing, so that
if full power is required in an emergency near
the ground the engine will operate satisfactorily and will not over-heat because of too
lean a mixture.
(8) Adjustment of Carburetor.
H, after checking all other points on engine, it is
found necessary to readjust the carburetor, proceed
as follows:
With engine thoroughly warmed up, set Throttle
Stop Screw so that engine idles at approximately
550 R.P.M. Turn Idle Adjusting Needle out slowly
until engine "rolls" from richness, then turn needle
in slowly until engine -"lags," or runs "irregularly"
from leanness. This step will give an idea of the
adjustment range and of how the engine operates under these extreme idle mixtures. From the lean
setting, turn needle out slowly to the richest mixture
that will not cause the engine to "roll" or run unevenly. This adjustment will in most cases give a
slower idle speed than a slightly leaner adjustment,
with the same Throttle Stop Screw setting, but will
give smoothest idle operation. A change in idle
mixture will change the idle speed and it may be
necessary to readjust the idle speed with Throttle
Stop Screw to the desired point. ';I'he Idle Adjusting
Needle should be from 3/4 to 1 turn from its seal to
give a satisfactory idle mixture.
48
Care should be taken not to damage the idle
needle seat by turning the idle adjusting
needle too tightly against seat, as damage to
this seat will make a satisfactory idle adjustment very difficult.
(9) Float Height (3, Fig. 32.)
The float height is set at the factory, and can be
checked by removing the throttle body and bowl cover
and float assembly and turning upside down. Proper
setting of the two floats should measure 7/32" from
bowl cover gasket to closest surface of each float.
Be sure to check both floats to proper dimenSions,
making sure that the floats are parallel to the bowl
cover gasket.
(10) Starting - Cold Engine.
With mixture control in full rich pOSition prime
the engine as directed by the engine manufacturers
instructions and set the throttle approximately 3/32"
from the throttle stop screw. With the throttle in this
position, turn the engine over two or three times before ignition is turned on. This will draw a finely
emulsified mixture of air and fuel through the manifold into the combustion chamber, then if the ignition
is turned on, the engine should start on the next turn
over and with the throttle stop 3/32" from the
throttle stop screw there should be sufficient throttle
opening to keep the engine running. The carburetor
is calibrated to give the richest mixture at this
throttle opening, and therefore, a cold engine will
run the smoothest with the throttle in this position.
For this reason the engine should be allowed to
warm up for several minutes before opening the
throttle further.
(11) Starting - Hot Engine.
To start a warm or hot engine, put mixture control in fuil rich pOSition and pull the throttle stop
back against the throttle stop screw. H the ignition
has just been shut off, turn on the ignition and the
engine should start on the first turn, but if the engine
has been shut off for several minutes, it may be
necessary to turn the engine over once or twice before turning on the ignition. A warm or hot engine
should start and continue with the throttle in the
idling position.
Do not open and close throttle in starting as
this is likely to deposit raw gasoline in the
carburetor air box and constitute a definite
fire hazard. Do. not prime a hot engine.
Section 15
FOR BENDIX S6LN .. 21 MAGNETOS
USER OPERATING INSTRUCTIONS
DESCRIPTION
The Bendix S4 and S6 series magnetos are desIgned for
use on four and six cylinder aircraft engines.
The two pole rotating magnet is mounted in the
housing on two annular ball bearings. On the rear
extension of the magnet shaft is the breaker cam.
The contact and cam follower assembly, incorporating a lubricating felt attached to the cam follower, is secured to the housing with two screws.
The coil is secured with two clamps, two screws and
lock washers. The primary lead from the coil is
secured directly to the adjustable contact assembly.
The secondary lead is grounded to the housing. The
two sections of the magneto are held together with
five screws.
INSTALLA TION
Before installing on the engine, make sure that the
magneto has been properly checked and inspected.
Remove the timing inspection plug and breaker cover.
Look into the inspection hole and turn the magneto until
the white tooth of the distributor gear lines up with the
timing mark or pointer. If the magneto incorporates an
impulse coupling, it will be necessary to depress the pawl in
order to rotate the magneto in the normal direction. At the
instant the marks line up, the points should be just starting
to open. Use a Bendix 11-851 Timing Light or equivalent to
check this. If necessary, adjust the breaker assembly as
described under INSPECTION AND MAINTENANCE.
NOTE
The special breaker grounding spring used on
these magnetos short-circuits the primary at
all times when the ground terminal is not installed. To prevent this from interfering with
the action of the timing light, an insulating
strip of heavy paper should be placed between
the breaker grounding spring and the magneto
housing.
After checking the magneto, turn the engine to the full
advance No.1 cylinder firing position on the compression
stroke as instructed in the engine handbook. Set the
magneto at the position where the timing marks seen
through the inspection hole line up as previously outlined.
Install the magneto on the engine. Connect Bendix I I -85 I
timing light, or equivalent, across the breaker points of the
magneto and rotate the magneto through the angle
provided by the elongated slots in the mounting flange until
the timing light indicates that the points are just opening on
the No. I cylinder. Secure the magneto in this position and
recheck the adjustment.
I
WARNING
I
Do not fail to remove the paper strip from
the magneto after the timing is finished. If
the paper strip were inadvertently left in the
magneto, the effectiveness of the grounding
spring would be lost.
Connect the ground wire to the ground terminal
connection on the breaker housing. Some installations have the ground terminal connection located on
the bottom of the housing. On some engines this
location results in an interference against an engine
accessory, preventing insertion of the ground terminal
insulating sleeve. To facilitate insertion of the
sleeve on these installations, a special split sleeve is
used, which can easily be inserted by pushing each of
its two parts into position separately.
The high tension terminals are supplied in kit
form, separate from the magneto. The cables are
attached in the following manner. The high tension
outlet marked "1" is to be connected to the No.1
cylinder. The sparks are delivered to the various
outlets in the same rotation as that of the magneto,
i.e., to the right for a clockwise magneto; left for
anticlockwise.
INSPECTION AND MAINTENANCE
The ball bearings of the magneto are packed in
grease and require no lubrication except when the
magneto is disassembled for overhaul.
At routine inspection intervals, remove the breaker
cover and inspect the breaker. Turn the engine until
the timing marks line up correctly. (See "Installation"). With the marks lined up, the bre~er
should be just starting to open. If the points do not
open at this pOSition, loosen the screw in the slotted
hole of the breaker assembly and shift the breaker
slightly so that the points just break contact when
the marks line up.
If the breaker pOints are oily, they can be cleaned
with a little clear gasoline. Avoid getting the gasoline on the breaker as the cam is impregnated with
lubricant, which would be washed away by the
gasoline.
If the breaker points are burned or worn excessively, do not try to redress the contact surfaces.
Install a complete new breaker assembly if they are
found to be in an unsatisfactory condition.
I
WARNING
I
Do not under any circumstances remove the
five screws which hold the two sections of the
magneto together, while the magneto is on the
engine. To do so would disengage the distributor gears, causing the distributor timing
to be "lost" and necessitate complete removal and retiming of the magneto.
49
Section 16
HYDRAULIC TAPPETS
SERVICE INSTRUCTIONS
TIDNGS TO BE REMEMBERED
IN
HANDLING:
1. Plungers not interchangeable:
The plunger in the hydraulic unit is not interchangeable in the cylinder as tests are made after
assembly for the ratA of leak-down, which determines the quality of the unit rather than diametric
clearances.
2. Plunger spring must be snapped in counterbore:
Any time the plunger is removed from the bore
and replaced, the plunger spring should be snapped
into the counterbore of the hydraulic cylinder. This
can readily be done by a slight twisting motion in the
direction to wind up the coil of the spring.
3. No grinding or machining to be done on unit:
It is not advisable to do any kind of grinding or
machining on the hydraulic units. In cases where
valves have been reseated to a depth which would require increasing their mechanical clearance, the
valve stems should be ground off to provide this
clearance.
4. Shellac or gasket cement not to be used:
No shellac or gasket cement of any kind should be
used at any point where it will be possible for it to
get into the hydraulic tappets, as this will cause the
check-ball to be glued to the seat and prevent
operation.
ESSENTIALS OF OPERATION:
1. Body free in guide:
The tappet body, itself, must be a free fit in the
guide. A proper test for this is to insure that the
tappet will drop of its own weight in the guide.
2. Check-ball must not leak:
The check-ball must not leak more than about one
drop per second when filled with kerosene, and the
plunger loaded with 50 lbs. pressure.
3. Check-ball travel must not be too great.
The check-ball should not have more than .014"
travel. This is provided for in manufacturing and it
would be very seldom the travel would exceed this
amount.
4. Plunger must be free in bore:
The plunger must be a free fit in the hydraulic
cylinder and, at the same time, the leakdown rate
must be right. The production limit is 1/4" travel
with 50 lbs. load in not less than four seconds when
unit is filled with kerosene.
Fixtures are available for service inspection
which compare a unit to be tested with a master unit.
As there are a number of these fixtures, the method
of testing is not given here, therefore reference
should be made to the instructions provided with
each fixture.
5. Tappets must have proper mechanical clearance:
50
The mechanical clearance should be checked each
time installation is made. This check should be
made without oil in the unit.
6. Proper oil supply must be maintained:
Oil must be supplied to the hydraulic tappets with
at least three or four pounds of pressure at idle and
twenty pounds of pressure at high speeds; and the
maximum oil pressure should not exceed fifty-five
pounds for any great period of time, as excessive oil
pressure can cause the entire hydraulic unit to pump
up and down in the body, preventing compensation,
resulting in noise.
HANDLING:
The usual handling will be: Removal for valve
grind or some other repair or replacement, in which
case it is only necessary to wash-up the hydraulic
tappets, removing the plunger from the hydraulic cylinders one at a time to prevent interchanging,
washing them thoroughly in clean gasoline, kerosene,
or any cleaning solution used for other parts and replacing them in the engine without any attempt being
made to fill them with oil before assembly. After
assembly, check clearance using a screwdriver to
pry the plunger down. With valve in closed pOSition,
measure the clearance between the end of the plunger
and the valve stem. Running the engine, the Illllts
should quiet themselves usually within forty-five
minutes in a horizontal engine. The time required
for any given unit to quiet is not indicative of the
quality but means only that the particular unit has a
larger amount of air to dispose of.
The engine should be run at the lowest speed which
produces maximum oil pressure, until all tappets
have become quiet.
It often happens that when a hydraulic unit is
operated in an engine for a considerable length of
time, carbon may form on the inside of the cylinder
above travel of the plunger during normal operation.
If this takes place, the plunger will appear to be stuck
in the cylinder. The following is the condition which
actually occurs in this case:
Removal of the valve stem from the top of the
plunger allows the plunger to move upwards and the
hydraulic unit completely fills with oil. The carbon
which has formed on the inside of the cylinder above
the shoulder on the plunger makes removal of the
plunger very difficult and, since the unit has filled
with oil, the plunger cannot be forced down because
the oil is trapped by the check-ball. This gives the
impreSSion of a stuck unit and, in order to free the
plunger, the following can be applied:
Press the plunger all the way down while holding
the check valve off its seat with a matchstick or
other blunt instrument. This will allow the oil to
escape and permit the unit to be checked with the
leak-down tester. In most cases the carbon which
has formed above the plunger can usually be broken
by twisting the plunger and pulling outwards at the
same time. In case the carbon buildup is quite great
and cannot be removed easily, it is advisable to
place the unit in a solution which will dissolve the
carbon ring. Once the plunger has been removed any
carbon remaining on the cylinder should be cleaned
off with a rough rag. The cylinder and the plunger
should then be washed thoroughly before reassembling.
In replacing the plunger into the cylinder, give it
a twist, while it is fully depressed; this will cause
the end of the spring to snap into its seat.
TYPES OF FAILURE:
With respect to failure of hydraulic tappets, there
are four general classifications:
1. Where very slight single or multiple noise is
heard.
2. Where a Single loud noise will be heard.
3. Where there is general noise in the entire set.
4. Intermittent or general noise in any particular
section of the engine.
1. Slight Noise:
In the case of item 1, there is a variety of things
other than the hydraulic tappet which can cause the
trouble; such as, excessive clearance between the
valve stem and the guide, eccentricity of the valve
seat or anything which can cause the valve to contact
the seat in closing at a point materially above the
point where the valve sets on the seat.
In cases where this type of noise is made by the
unit itself, it is due either to a leaky check valve or
a plunger having too much clearance in the bore.
2. Loud Noise:
With reference to item 2 where single loud noise
is heard in the valve gear: It is generally found that
for some reason a hydraulic plunger has become
sticky or tight in the bore to such an extent that the
plunger spring will not move the plunger in the bore.
This results in the plunger being forced all the way
down so that the bottom of the plunger contacts the
ball cage and the tappet clearance is approximately
1/16".
The particular tappet causing the trOuble can be
located in the following manner: By using some kind
of listening rod and comparing the noise in each cylinder, it can readily be determined which cylinder
the noisy tappet is in. Very often by listening directly over the exhaust or the intake, the individual tappet can be determined before disassembly. In any
case, removal of these two tappets and examination
will disclose which one has been sticking.
It will be found that the seating of the valve where
a hydraulic unit is stuck produces a very perceptible
shock to the valve spring at the instant of seating.
This can readily be determined by either touch or
sound. One readily accessible method is to push the
end of a hammer handle against the valve spring
keeper. If the tappet is noisy, a decided shock will
be felt at the instant of clOSing. Whereas when the
tappet is working properly there will be almost no
shock felt. Once this comparison is made, there will
be no question about its finality thereafter.
If it is found that one unit has a tendency to stick
due to oil varnish, it is very likely that all units may
need immediate attention to prevent a recurrence of
sticking.
3. General Noise:
In cases of general noise in the entire set (item
3), it is a definite indication that insufficient oil is
being delivered to the hydraulic units. As a general
rule, in cases where engines run out of oil the hydraulic units will provide a warning before serious
damage is done as air will periodically be taken into
the intake side of the pump as soon as the level is
very low. ThiS, however, is not recommended as a
means for determining when oil is needed in the
engine. In any case where general noise is observed,
it is advisable to determine oil pressures at the hydraulic tappets.
4. Intermittent or General Noise:
In the case of item 4, the general or intermittent
noise in any particular section of the engine is
usually an indication that air separation is inadequate
at this point. This type of noise will usually occur
when the engine is brought down to idle from high
speed, or possibly in some cases on starting. This is
usually a question of design and not often encountered
in the field.
However, there have been some examples of
individual engines where some air-leak occurred on
the intake side of the oil pump, providing excessive
aeration, so that the air separation provided in the
job may be adequate - either for all or part of the
engine. In any case, if this trouble should be found,
the inlet side of the pump should first be examined
for air leaks - particularly as excessive aeration is
apt to cause trouble in bearings or other parts of the
engine. If no air leak is found, any arrangement
which will increase the capacity for air separation
may remedy the trouble.
In some cases it has been found that the valves
were definitely being held open, causing defective
performance; but this has been found to be something
other than the hydraulic tappets themselves - generally a camshaft with sufficient runout on the base
circle of the cams to crack the valves off the seat
when they should be closed. The maximum allowable
runout on the base circle of a cam used with hydraulic tappets is .002" total indicator reading. It is not
likely that many cases of this condition would be
found.
5. To Summarize:
Noisy operation of hydraulic tappets is likely to
result from inadequate oil supply, dirt, or air in
the oil, etc., as outlined above and usually is not
caused by any structural failure of the hydraulic unit
itself.
Remember that no adjustment is necessary or
possible on hydraulic tappets and that they are designed as a sturdy part of the engine to give long and
trouble-free service - provided they are correctly
handled and provided they are supplied with clean
oil at the correct pressure. Therefore, it is advisable to leave them alone unless noisy operation is
due to one of the causes mentioned above.
51
Section 17
DELCO.. REMY STARTER
DELCO-REMY NO. 1109656, AIRCRAFT 12-VOLT STARTER
CONTINENTAL NO. 50309
Figure 33. Starter.
(a) General.
The starting motors used on the A100, C115 and
C125 engines are designed to give maximum cranking
performance with minimum weight.
The Delco-Remy Model 1109656 is a special 12volt, 4 field unit with manual operation overrunning
clutch type drive. The armature is supported by oilless bushings in both the drive end and the commutator end. An oil seal in the drive end protects the
cranking motor from oil in the flywheel housing. The
driye pinion is manually engaged with the flywheel
ring gear by the shift lever movement when the
cranking motor switch is closed and the cranking
motor armature begins to rotate. When the engine
starts, the overrunning action of the clutch protects
the drive pinion until the shift lever can be released
to disengage the pinion from the flywheel.
Cranking motor specifications are:
Clockwise rotation viewing drive end. (Clutch
rotation)
Brush spring tension - 24-28 ounces.
No load - 1200 r.p.m, at 65 amperes at 11.35
volts.
Lock torque - 60 lbs. ft. at 450 amperes at 3.9
volts,
(b) Installation.
With the pinion pivot well oiled, remove clutch
and gear assembly from starter adapter housing and
insert over pinion pivot. Place the .006 inch thick
gasket over the three 5/16 studs being careful that
the top end of gasket is kept in place. Assemble
starter and adapter over 3/16 studs and clutch gear,
52
making sure the leather washer between clutch gear
shaft and adapter housing is in place.
(c) Assemble the two 5/16 x 3-3/8 drilled head bolts
with plain washers thru the crankcase and crankcase
cover into the starter. Tighten nuts and bolts evenly,
secure nuts with palnuts and bolts with safety wire.
(d) Adjustment of Starter Shift Lever.
It is very important that the cable or wire control
return spring should have sufficient tension to bring
lever to fully released position when control is released. It is also necessary that there be 1/16 inch
minimum clearance between clutch shaft end and
starter shift lever when control is released. There
is 9/16 in. of travel at the starter gear pinion. It is
very important that the starter lever compresses the
starter pinion gear 7/16 in. of its travel before contacting the starter switch, the remaining 1/8 in. of
travel will be used in making the electric contact of
the starter switch.
(e) It is important that No. 2 wire be used between
starter motor and battery to avoid any excessive
TYPICAL
WIRING
DIAGRAM
REGULATOR
ci
z
+
':'(FIELD SWITCH TO
BE COINCIDENTAL
WITH MAINLINE SW)
,.,
CRANKING MOTOR
V
BATTERY
WIRE SIZES SHOWN ARE MINIMUM AND SHOULD BE
- -ONLY
--------------WHERE ~~ ARE ~
-USED
Figure 34. Typical Wiring Diagram.
voltage drop.
(f) Cranking Motor Maintenance
Cranking motor maintenance may be divided into
two sections - the normal maintenance required to
assure continued operation of the cranking motor and
the checking and repair of an inoperative unit.
(1) Normal Maintenance
Lubrication - Oilless bushings are used in this
motor and require no lubrication
Inspection - The cover band should be removed
and the commutator and brushes inspected at regular intervals. If the commutator is dirty, it may be
cleaned with No. 00 sandpaper. Blowout dust. Never
use emery cloth to clean commutator. If the commutator is rough, out of round, or has high mica, it
should be turned down in a lathe. The mica should be
undercut to a depth of 1/32 of an inch. Worn brushes
should be replaced. If brushes wear rapidly, check
for excessive brush spring tension and roughness or
high mica on the commutator.
Cranking Motor Disassembly
At regular intervals, the actual time depending on
the type of operation, the cranking motor should be
disassembled for a thorough cleaning and inspection
of all parts. Never clean the armature or fields in
any degreasing tank, or with grease dissolving
materials, since these may damage the insulation.
Never wash bearings in gasoline or other solvent
since this would remove the grease and ruin the
bearings. The commutator should be trued in a lathe
if necessary. Replace all parts showing excessive
wear. All wiring and connections should be checked.
Rosin flux should be used in making soldered connections. Acid flux must never be used on electrical
connections. Submit reassembled unit to NO- LOAD
and LOCK tests.
(2) Checking of Improperly Operating Cranking
Motor
The shift lever on the cranking motor, whether
operated by a cable or wire control, should have a
return spring with sufficient tension to bring the lever
to the fully released position when .the control is released. This action should be checked occasionally
to make sure that the spring is returning the lever to
its fully released position.
In this position, there should be 1/16 inch clearance between the lower end of the shift lever and the
button on the back of the overrunning clutch drive
(See Fig. 33.)
If the cranking motor does not develop rated torque
and cranks the engine slowly or not all, check the
battery, battery terminals and connections, and
battery cables. Corroded, frayed, or broken cables
should be replaced and loose or dirty connections
corrected. The cranking motor switch should be
checked for burned contacts and the switch contacts
cleaned or replaced if necessary.
If all these are in order, remove the cover band
of the cranking motor and inspect the brushes and
commutator. The brushes should form good contact
with the correct brush spring tension. A dirty commutator can be cleaned with a strip of No. 00 sandpaper held against the commutator with a stick while
the cranking motor is operated. NEVER OPERATE
MORE THAN 30 SECONDS AT A TIME TO AVOID
OVERHEATING, AND NEVER USE EMERY CLOTH
TO CLEAN COMMUTATOR. If the commutator is
very dirty or burned, or has high mica, remove the
armature from the cranking motor and take a cut off
the commutator in a lathe. The mica should be under
cut to a depth of 1/32 inch. If there are burned bars
on the commutator, it may indicate open circuited
armature coils which will prevent proper cranking.
Inspect the soldered connections at the commutator
riser bars. An open armature will show excessive
arcing at the commutator bar which is open, on the
no-load test.
Tight or dirty bearings will reduce armature
speed or prevent the armature from turning. A bent
shaft, or loose field pole screws, will allow the
armature to drag on the pole shoes, causing slow
speed or failure of the armature to revolve. Check
for these conditions.
If the brushes, brush spring tension and commutator appear in good condition, and the battery and
external circuit found satisfactory, and the cranking
motor still does not operate correctly, it will be
necessary to remove the cranking motor for no-load
and torque checks.
No-Load Test
Connect the cranking motor in series with a
battery of sufficient voltage, a heavy variable resistance and an ammeter capable of reading several
hundred amperes. If an r .p.m. indicator is available,
read the armature r .p.m. in addition to the current
draw. Be sure to adjust the resistance to obtain the
proper voltage.
Torque Test
It is advisable to use in the circuit a high current
carrying variable resistance so that the specified
voltage at the motor can be obtained.
A small
variation of the voltage will produce a marked
difference in the torque developed.
Interpreting results of NO-LOAD and TORQUE
TESTS.
1. Rated torque, current draw and no-load speed
indicates normal condition of cranking motor.
2. Low free speed and high current draw with low
developed torque may result from:
a. Tight or dirty bearings, bent armature shaft
or loose field pole screws which allow the
armature to drag.
b. Shorted armature. Check armature further
on growler.
c. A grounded armature or field. Check by
raising the grounded brushes and insulating
them from the commutator with cardboard
and then checking with a test lamp between
the insulated terminal and the frame. If
test lamp lights, raise other brushes from
the commutator and check field and commutator separately to determine whether it
is the fields or armature that is grounded
3. Failure to operate with high current draw:
a. A direct ground in the switch, terminal or
fields.
b. Frozen shaft bearings which prevent the
armature from turning.
4. Failure to operate with no current draw:
a. Open field circuit. Inspect internal connections and trace circuit with a test lamp.
b. Open armature coils. Inspect the commutator for badly burned bars. Running free
speed, an open armature will show e~ces.
sive arcing at the commutator bar whlch IS
53
open.
c. Broken or weakened brush springs, worn
brushes, high mica on the commutator, or
other causes which would prevent good contact between the brushes and commutator.
Any of these conditions will cause burned
commutator bars.
5. Low no-load speed, with low torque and low
current draw indicates:
a. An open field winding. Raise and insulate
ungrounded brushes from commutator and
check fields with test lamp.
b .. High internal resistance due to poor connections, defective leads, dirty commutator
and causes listed under 4c above
6. High free speed with low developed torque and
high current draw indicates shorted fields. There is
no easy way to detect shorted fields, since the field
resistance is already low. If shorted fields are
suspected, replace the fields and check for improvement in performance.
Section 18
DELCO-REMY GENERATOR
DELCO-REMY NO. 1101876
CONTINENTAL NO. 40435
Figure 35. Generator.
(a) General.
The generator used on the A100, Cll5 and C125
Continental Engine is of the direct drive 12 volt
shunt wound type, and is so designed as to give
maximum performance with minimum weight.
The Delco-Remy Model 1101876 Generator is a
special aircraft type, 12-volt, 12 ampere unit. The
armature is supported at both the drive end and commutator end by sealed ball bearings which require no
lubrication. The drive end has windows and the cover
band is provided with a fitting for connection with a
blast tube. The blast tube must be connected to a
source which will maintain a minimum of 1.5 inches
of water pressure differential across the generator.
This will assure an adequate flow of air through the
generator and proper generator ventilation.
Specifications are as follows:
Clockwise rotation viewing drive end.
Cold output 13 amperes at 15.0 volts at 3650
r.p.m.
54
(Maximum output controlled by current
regulator)
Field current at 12 volts - 1.62-1.69 amperes.
Brush spring tension 25 ounces.
(b) Installation
Generators are received from Delco-Remy less
oil-seal, hub coupling rubber drive disc, and dr:i.-ve:
gear. To prepare for assembly to engine, assemble
the following parts.
(1) Drive oil seal in place (lip facing engine), make
sure Woodruff key is in place.
(2) Drive generator hub coupling to where it
bottoms on shoulder of generator shaft. While driving hub on, check to see that key stays in place.
(3) Assemble rubber disc with groove side up.
(4) Assemble generator drive gear on shaft, fitting
lug on gear into rubber groove.
(5) Insert special 5/16 washer over generator shaft,
screw on 5/16 shear nut and secure with 1/16 x 3/4
cotter pin.
(6) When generator drive gear is in place trim off
excess rubber from drive disc.
NOTE
Generator and Tachometer drive housing
both use the same gasket. It is recommended
tachometer housing be assembled last and removed first, when removing generator.
(7) Assemble generator to crankcase housing, with
the generator terminals facing toward 2-4 cylinder
side of motor (9 o'clock position).
(8) Place 5/16 plain washers over the three studs,
tighten the three nuts and secure with palnuts.
(c) Generator Maintenance.
Generator maintenance may be divided into two
sections - the normal maintenance r e qui red to
assure continued operation and the checking and repair of an inoperative unit.
(1) Normal Generator Maintenance
Lubrication - Since the armature is supported at
both ends by sealed ball bearings no lubrication of
the generator is required.
Inspection - The cover band should be removed
and the commutator and brushes inspected at regular intervals. If the commutator is dirty, it may be
cleaned with No. 00 sandpaper. Blowout dust.
NEVER USE EMERY CLOTH TO CLEAN COMMUTATOR.
If the commutator is rough, out of round, or has
high mica, it should be turned down in a lathe and the
mica undercut. Worn brushes should be replaced.
They can be seated with a brush seating stone. The
brush seating stone -is an abrasive material which,
held against the revolving commutator, car r i e s
under and seats the brushes in a few seconds. Blow
out dust. NEVER USE EMERY CLOTH. Check brush
spring tension, which should be approximately 25
ounces.
Generator Disassembly.
At regular intervals, the actual mileage or time
depending on the type of operation, the generator
should be disassembled for a thorough cleaning and
inspection of all parts. Never clean the armature or
fields in any de greasing tank, or with grease dissolving materials, since these may damage the insulation. The ball-bearings should never be washed
in gasoline or any other solvent since this would
dissolve the grease in them and ruin the bearings.
The commutator should be trued in a lathe and the
mica undercut if necessary. All wiring and connections should be checked. Rosin flux should be
used in making all soldered connections. Acid flux
must never be used on electrical connections.
(2) Checking Inoperative Generator.
Several conditions may require removal of the
generator from the engine and further checking of the
generator as follows:
1. No output
2. Unsteady or low output
3. Excessive output
4. Noisy generator
1. No Output
Remove cover band and check for sticking or worn
brushes and burned commutator bars. Burned bars,
with other bars fairly clean, indicate open circuited
coils. If brushes are making good contact with commutator and commutator looks okay, use test leads
and light and check as follows:
a. Raise grounded brush, check with test pOints
points from "A" terminal to frame. Light
should not light. If it does, the generator is
grounded; raise other brush from com-
mutator and check field, commutator and
brush holder to locate ground.
b. If the generator is not grounded, check field
for open circuit.
c. If this field is not open, check for shorted
field. Field draw at 12 volts should be 1.62
to 1.69 amperes. Excessive current draw
indicates shorted field.
d. If trouble has not yet been located, remove
armature and check on growler for short
circuit.
2. Unsteady' or Low Output
Check as follows:
a. Check brush spring tension and brushes for
sticking.
b. Inspect commutator for roughness, grease
and dirt, dirt in slots, high mica, out of
round, burned bars. With any of these
conditions, the commutator must be turned
down in a lathe and the mica undercut. In
addition, with burned bars which indicate
open circuit, the open circuit condition must
be eliminated or the armature replaced.
3. Excessive Outp'ut
Excessive output usually results from a grounded
generator field - grounded either internally, or in the
regulator. Opening the field circuit (disconnecting
lead from "F" terminal of regulator or generator)
with the generator operating at a medium speed will
determine which unit is at fault. If the output drops
off, the regulator is causing the condition. If the
output remains high, the field is grounded in the
generator, either at the pole shoes, leads, or at the
"F" terminal.
4. Noisy. Generator
Noisy generator may be caused by loose mounting
or drive pulley, or worn, dry or dirty bearings, or
improperly seated brushes. Brushes may be seated
by using brush seating stone, referred to above.
Installation Caution
After the generator is reinstalled on the engine,
or at any time after leads have been disconnected
and then reconnected to the generator, a jumper lead
should be connected MOMENTARILY between the
BATTERY and GENERATOR terminals of the regulator, before starting the engine. This allows a
momentary surge of current from the battery to the
generator which correctly polarizes the generator
with respect to the battery it is to charge. Failure to
do this will result in vibrating and arcing relay cutout
pOints which will soon be ruined so that regulator replacement will be required. In addition, the battery
will not charge so it may run down.
Section 19
DELCO-REMY GENERATOR REGULATOR
General
Delco-Remy Voltage Regulators for aircraft installation combine three units, a cutout relay, a
current regulator and a voltage regulator, mounted
on the same base and enclosed by a single cover.
These three units provide complete control of ilie
55
VOLTAGE REGULATOR UNIT
LOWER SPRING HANGER
IOCD DOWN to tNCUAS( VOUAG( SlTTHG
.,..., ... TO OfUlASl VOLTAGE SlmNG
CURRENT REGULATOR UNIT
LOWER SPRING HANGER
_NO DOWN TO INOlA$( CUlltNf StT11NG
ItNO UP" to OtCHA$( (~Nt srt1»tG
MAKE ADJUSTMENT ON ONE SPRING
(HANG< llNSlOH ON 10TH SPltNGS ONLY .......
ACUUStM[NT Of ONE SHtNG WILL HOT IItIMG
$(1'11NG W1l'KN SPtCIIICAOONS.
Figure 36, Current and Voltage Regulator.
generator output under all normal operating conditions. The Cutout relay closes and opens the circuit between the battery and generator as the engine
starts or stops. The current regulator prevents the
generator from exceeding its maximum rated output.
The voltage regulator protects the circuit from high
voltage, and prevents battery overcharging by tapering off the generator output as the battery becomes
fully charged.
The regulator should be mounted on the firewall or
some structure of the airplane relatively free of
vibration. The regulator base must be grounded to
the engine. The ground strap on the regulator
automatically grounds the regulator base to the
structure to which it is mounted and this structure
must be grounded to the engine to assure a complete
circuit. Ground negative terminal of battery.
Servicing.
(1) A fully charged battery and a low charging
rate indicate normal voltage regulator operation.
(2) A fully charged battery and a high charging
rate indicate the generator field circuit is grounded
either internally or in the wiring harness. To determine the reason, proceed as follows:
(a) Disconnect the "F" terminal lead from the
regulator, this opens the generator field circuit and
the output should normally drop off.
(b) If the output drops off to zero, the trouble has
been isolated in the regulator. Reconnect the "F"
terminal lead, remove the regulator cover and depress the voltage regulator armature manually to
open the points. If the output now drops off, the
56
the voltage regulator unit has been failing to reduce
the output as the battery comes up to charge and adjustment of voltage regulator is necessary.
(c) If separating the voltage regulator contacts
does not cause the output to drop off, inspect the
field circuit within the regulator for shorts. Pay
particular attention to the bushings and insulators
under the contact points and make sure the insulators
are correctly assembled.
(3) With a low battery and a low or no charging
rate, check the circuit for loose connections, frayed
or damaged wires. High resistance resulting from
these conditions will prevent normal charge from
reaching the battery. If the wiring is in good condition then either the regulator or generator is at
fault. Ground the "F" termtnal of the regulator
temporarily and increase generator speed to determine which unit needs attention. Avoid excessive
speed, since under these conditions the generator
may produce a dangerously high output.
(a) If the output does increase, the regulator needs
attention. Check for dirty or oxidized contact points,
or a low voltage setting.
(b) If the generator output remains at a few
amperes with the "F" terminal grounded, the generator is at fault and should be checked further.
(c) If the generator does not show any output at
all, either with or without the "F" terminal grounded,
quickly disconnect the lead from the "GEN" terminal
of the regulator and strike it against a good ground
with the generator operating at a medium speed. If
no spark occurs the trouble has now been definitely
isolated in the generator and repairs are necessary.
If a spark does occur likely the generator can build
up, but the cutout relays will not operate due to
burnt points, points not closing, open shunt winding,
ground, high voltage setting, or other causes. Do not
operate generator with the "GEN" terminal lead
disconnected for any length of time, since this is an
open circuit operation and the units would be damaged.
CLEANING CONTACT POINTS
Cleaning the contact points of the current and
voltage regulator properly is one of the most important operations the mechanic will be called on to
perform. Dirty or oxidized contact points arc and
burn, cause reduced generator output and rundown
batteries. If the points are properly cleaned, the
regulator will be restored to norxml operation. If
improperly cleaned, improvement in performance
will be small and only temporary. The points should
be cleaned one at a time. Loosen the two contact
mounting screws so the upper contact bracket can be
swung to one side, or the contact bracket may be removed if necessary. Never use sandpaper or emery
cloth to clean contact pOints.
ADJUSTMENTS
Adjustments of the voltage regulator may be made
by ex per i e n c e d mechanics; however, it is recommended the unit be serviced by an Authorized
Delco-Remy Electrical Service Station.
SECTION 20
STARTER
AND
ADAPTER
1. GENERAL.
a. The electric starter is mounted on a right angle
drive adapter which is attached to the upper rear of the
crankcase cover. The tongue of the starter coupling
mates with a slot in the end of the worm gear shaft.
The worm gear shaft is supported by a needle bearing
on its left end and a ball bearing on the right. Torque
is transmitted from the shaft to the worm gear by a
Woodruff key. The helical teeth of the worm gear drives
the worm wheel. A heavy helical spring covers the
externally grooved drum of the worm wheel and a similarly grooved drum on the shaft gear. The front end
of the spring fits closely in a steel sleeve which is
pressed into the adapter. When the starter is energized, the spring tightens up on the shaft gear drum,
locking the worm wheel and shaft gear together to
transmit torque to the crankshaft gear. When the engine starts, the shaftgear is driven by the engine. This,
plus the fact that the starter is no longer operating,
permits the shaftgear to become disengaged from the
spring.
4. CLEANING.
a. Use a fortified mineral spirit solvent, sold under
various trade names, for degreasing. If rosin (oil
varnish) or stubborn carbon deposits must be removed
from the aluminum casting, it may be immersed in an
agitated bath of an inhibited mild alkaline cleaning solution marketed for that purpose. The bath should be
maintained at a temperature of 180°F to 200°F. The
parts should remain in it only long enough to loosen
the deposits. Immediately after such cleaning, flush
away all traces of the alkaline material with a jet of
wet steam or by repeated brush application of a mineral spirit solvent.
2. REMOVAL (See Figure 37. )
a. Remove three sets of attaching parts (1,2 and 3)
and one set of attaching parts (4,5,6 and 7). Pull
starter and adapter assembly straight away from
crankcase cover studs. Remove gasket (8).
b. Trichlorethylene condensation plants provide excellent degreasing action for steel, aluminum and
bronze parts. Their disadvantages lie in the toxic
quality of the vapors, removal of the enamel from
painted parts, and drying and hardening effect on carbon deposits.
c. No polishing compound or abrasive paste or powder
should be used for cleaning starter adapter assembly
parts. Do not use wire brushes or wheels, putty knives
or scrapers to remove hard carbon deposits, since
scratches resulting from such methods allow a concentration of stress at the scratch and may cause fatigue failure.
3. DISASSEMBLY. (See Figure 37. )
a. Remove two sets of attaching parts (9,10 and 11),
starter (12) and packing (13). Remove four sets of attachingparts (14,15 and 16), cover (17) and gasket (18).
Remove one set of attaching parts (19, 20 and 21) and
the adapter cover assembly (22 through 27). Remove
packing (22).
b. To remove shaftgear and clutch spring from adapter, support vacuum pump drive end of adapter on wood
blocks and tap around front end of spring with a brass
drift.
c. Use an arbor press to remove shaftgear (33) from
bearing (31) and worm wheel (32).
d. Clamp the worm wheel between lead covered vise
jaws. Bend ears of tab washer (29) away from hex
flats of bolt (28). Remove bolt and tab washer. Turn
clutch spring (30) until its depressed rear end lies
across the 1/4 inch hole, in worm wheel hub. Insert
a screwdriver blade, 3/16 inch Wide, into hole and
pry spring outward clear of drum groove. Hold spring
end out while pulling spring from drum.
e. Remove retaining ring (34), bearing (35) and worm
drive shaft assembly. Remove worm gear (36), spring
(37) and Woodruff key (38) from shaft (39),
Any alkaline deposits remaining on engine
interior parts will react with acids formed
in the lubricating oil to form soap, which will
cause violentfoam and may result in failure
of the lubricating system.
5.
INSPECTION METHODS.
Bare steel parts should be covered with a corrosion
preventive oil except during actual inspection operations. Since inspection involves handling of dry steel
parts it is recommended that a fingerprint remover
solution be applied to the part because perspiration and
skin oils often have a high acid content. Application of
lubricating or corrosion preventive oil will not necessarily stop corrosion from this cause.
b. All parts should be visually inspected, under a good
light, for surface damage such as nicks, dents, deep
scratches, visible cracks, distortion, burned areas,
pitting and pickup of foreign metal. Visual inspection
should also determine the need for further cleaning of
obscure areas. Inspect studs for possible bending,
looseness or backing out. Inspect threads for damage.
a.
57
------~
12
38 39 35 34 13
,,~
~;~\~2~~
>~
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
Nut
Lockwasher
Flat washer
Lock nut
Nut
Flat washe
Bolt
r
Gasket
Lock nut
Nut
Flat washer
Starter
"0" rmg
"
Nut
Lock washer
Flat washer
Cover
Gasket
Bolt
Lock washer
Flat washer
"0" rmg
"
23.
24.
25.
26.
27.
28.
29.
30.
7I
11
!
Oil seal
Stud
Pin
Bushing
Adapt er cover
Screw
Tab washer
Clutch spri
Needle beanng
~
Worm wh
Starter s::':} gear
Retainin
t gear
Ball b g" ring
S
earmg
tarter worm
Spring
gear
40.
41. Dowel
42. Needle bear"
43. Starter adap~!
Starter and Adapter.
I
9
10
L@®@
31.
32.
33.
34.
35.
36.
37.
38. Woodruff ke
39. Worm
Stud d"
rlve Yshaft
Figure 37
58
-::::::::----
~
/_-----
-
Part Name
TABLE XVI. MAGNUFLUX INSPECTION CHART.
Direction of
Inspection
Current
Critical
Magnetization
(Amperes)
Method
Areas
Circular
Wet
Continuous
Longitudinal
Wet
Continuous
Starter Worm
Shaft
Circular
Wet
Continuous
Starter Worm
Gear
Longitudinal
Wet
Residual
Starter
Shaftgear
c. Inspection by the 1\.1:agnaflux method shoum be conducted on all ferrous parts listed in Table XVI and in
accordance with the methods and data in the table before dimensional inspection.
1500
1500
Teeth, Drum
Fatigue,
Heat Cracks
Shaft between
spur gear and
drum
Fatigue Cracks
Slotted end,
around Key
Slot
Fatigue Cracks
Teeth
Fatigue Cracks
.5625
.010 MAX'75620
;-COLD ROLLED STEEL BAR STOCK
~
+
~
l
SIDE VIEW
Before magnetic inspection of any part, plug
all holes with tight fitting plugs or with hard
grease (which is soluble in lubricating oil) to
prevent an accumulation of particles in remote, and hard to clean places. After inspection remove all such plugs and clean the
part thoroughly with solvent and dry with compressed air. Check for complete demagnetization.
Inspect
For
J,
I@
!S:
3
16
END
VIEW
NOTE: ALL DIMENSIONS IN INCHES ~ x 450CHAMFER
Figure 38.
Needle Bearing Installer.
d. Inspect aluminum alloy casting by fluorescent particle inspection method. The standard operating technique for the process is applicable.
e. Areas of running parts and bushings subject to wear
should be inspected for serviceable fit with mating
parts by comparative linear measurements and alignment measurements. This will be accomplished by
using standard measuring instruments s(Jch as micrometers, telescoping gauges and dial indicators.
6. REPAIR AND REPLACEMENT.
a. The parts listed in the Table of Limits should be
inspected dimensionally as described in paragraph 5e.
b. Do not attempt to replace adapter sleeve if surface
roughness is less than specified. Return to factory for
replacement.
c. If the needle bearing(42, figure 37)istobe replaced it may be removed either with an arbor press or
with the installer illustrated in figure 38. Installation
is described in figure 39.
d. If needle bearing (31) is to be replaced, press it
from worm wheel (32), and install a new bearing so it
is recessed 0.09 inch from either end of worm wheel
hub.
e. If bushing (26) is to be replaced it can be accomplished by drilling to a thin shell and collapsing or
pressing with an arbor press using a piloted drift.
Figure 39. Installing Needle Bearing.
59
After the bushing is removed, use a pair of diagonal cutters to pull
the pin (25). After the bushing is installed, drill a new hole (0.0580.060 dia x 0.31 inch depth) through the bushing flange and into
the cover hub. Drive a new pin (25) into the hole. Pin must be flush
or below surface of bushing flange.
f. Extension of studs (24) should be 0.62 and studs (41) should
be 0.88 inch. Replace any stud exhibiting damage or backing out
with the next oversize.
g. Replace oil seal (23). Remove carefully with either a soft drift
or standard puller.
7. REASSEMBLY. (See Figure 37.)
a. Press bearing (35) onto shaft (39). Install spring (37), wookruff
key (38) and worm gear (36). Insert assembly into adapter and
install retaining ring (34).
b. Install spring (30) on worm wheel (32). Turn spring so it tends
to unwind until offset end drops into gear hub groove. Position
spring on gear so screw notch is aligned with screw hole in gear
web. Install a new tab washer (29) and bolt (28).
c. Slide shaft gear (33) through front of adapter (43). Lubricate
spring, sleeve and shaft gear liberally with clean oil. Press worm
wheel, bearing and spring assembly down onto shaftgear. Make certain worm wheel and worm gear teeth are aligned. Install a new
packing (22) in cover assembly groove. Slide cover and seal assembly over shaft. Install one set of attaching parts (21, 20, and 19).
d. Apply a film of Tite Seal compound to both sides of gasket
(18) before installing it on cover studs (24). Install cover (17) and
four sets of attaching parts (16, 15, and 14).
8. INSTALLATION. (See Figure 37.)
a. Coat a new gasket (8) with Tite Seal compound and install it
on crankcase studs. Place adapter assembly on crankcase cover studs.
Install three sets of attaching parts (3, 2, and 1) and one set of
parts (7, 6, 5, and 4).
b. Install a new packing (13) on starter flange. Mount starter
(12) on adapter studs and install two sets of attaching parts (11,
10, and 9).
TABLE OF LIlVIITS
Ref.
No.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
60
Description
Starter Shaftgear in Bushing.•••••••• Dia.
Starter Shaftgear front journal••••••• Dia.
Starter shaftgear in needle bearing.•• Dia.
Clutch spring sleeve in adapter ..•..• Dia.
Starter shaftgear in cover bushing. .. Dia.
Bushing in adapter cover .••••..•.•.. Dia.
Oil seal in adapter cover.•.....•••.. Dia.
Cover pilot in adapter ............... Dia.
Worm wheel gear ..•...•.••..• end clear.
Clutch drum spring on clutch drum ... Dia.
Clutch spring on starter shaft
gear drum . • • • • • • • . . • • • • • . • . • • •. .. Dia.
Clutch spring to sleeve (sandblasted
dia finish). When sandblasted finish
is worn to 75 RMS replace sleeve •.•.
From center line of worm gear shaft
to starter adapter thrust pads ••••.•.
Needle bearing in starter adapter .••. Dia.
Ball bearing in starter adapter ....... Dia.
Worm gear shaft in needle bearing
...••...••.•. shaft dia.
Worm gear shaft in ball bearing••.•. Dia.
Starter worm gear on shaft. • • . • • • •• • Dia.
Starter spring on worm gear shaft•••• Dia.
Serviceable
Limit
0.0045L
1. 058
0.0031L
Min.
New Parts
Max.
0.015
0.012T
O.OOlL
1. 059
0.0005L
0.003T
O.OOlL
0.001 T
0.001 T
O.OOlL
0.0025
0.015T
0.003L
1. 060
0.0029L
0.005T
0.0025L
0.003T
0.007T
0.003L
0.0115
0.022T
0.013L
0.006L
0.009L
0.252
0.246
O.OOlL
O.OOlL
0.248
0.001 T
O.OOOlT
0.5600
0.5615
O.OOOlL
0.0005L
0.005L
0.5625
0.0007T
0.0025L
0.025L
0.0035L
0.004L
TABLE OF lJMITS (Cont.)
Ref.
No.
20.
21.
22.
23.
24.
Serviceable
Limit
Description
Starter pilot to starter drive adapter. Dia.
Starter drive tongue to shaft
drive slot .•••••••••••••••••• side clear.
Needle bearing to worm gear shaft
Dia.
Starter gear-to-crankshaft gear
••••••••••••• back lash.
Starter worm wheel-to-worm gear
•.•••••••••.• back lash.
13
Min.
New Parts
Max.
O.OOIL
0.0065L
0.030L
0.0031L
O.OlOL
0.0005L
0.021L
0.0029L
0.016
0.008
0.012
0.025
0.009
0.013
16-22
20
21
Figure 40. Table of Limits Chart.
61
Continental Motors, Inc.
www.continentalmotors.aero

C-125, C-145 and O-300 Series Engine Overhaul Manual

Transcription

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