rockers - Street Commodores

OFFYOUR
ROCKERS
Ben Hosking
West Australian company Forced Induction
Technologies has developed an easy mod that will
put the wind up your Ecotec’s skirt
O
ut of the box, the venerable Holden V6 – in this
case, the Ecotec to be specific – is a pretty decent
bit of gear. With 152kW at 5200rpm and 224lb.ft
torque at only 3600rpm (VX), the ‘little engine
that could’ has the goods to get you moving
pretty quickly with a minimum of fuss.
It won’t give you any heart attacks, though, but Forced
Induction Technologies (FIT) has developed a set of 1.9:1-ratio
replacement rockers that will put a little extra poke into your
daily driving experience.
Based on the factory 1.65:1 rockers, FIT’s high-ratio units see
OEM rockers remanufactured with repositioned pushrod seats
that effectively increase the ratio of the rockers to 1.9:1. This
gives the same effect of having a higher-lift camshaft without
the hours and expense of changing your cam.
For $795, you get the rockers, new rocker bolts, rocker mounting
plates and a tub of break-in lube, and all you need is a set of sockets, a screwdriver or two and a torque wrench (although you can
make do without the torque wrench if you’re careful).
Read on to see how easy it is to add around 13–16kW in only
1–2 hours. This modification is good for both the L36 N/A
Ecotec and the L67 S/C Ecotec engines.
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STEP 1
Looks like just about every
other V6 Commodore
engine bay in the country,
save for the Pacemaker
headers already fitted. But
within an hour or two, this
bent-six VX will kick a little
harder thanks to the FIT
rockers.
STEP 2
First move, grab your socket set and remove the four
nuts holding the engine
cover on. It might also be a
good time to disconnect
your battery, just to be on
the safe side.
STEP 3
Next, remove the brace
that connects the alternator to the valley area. The
alternator itself doesn’t
require removal.
STEP 4
With a little extra room to
move, start unbolting the
driver-side rocker cover.
You don’t need new gaskets for this job, as the V6
uses reusable rubber gaskets. On the passenger’s
side, the dipstick tube
needs to be unbolted and
swung out of the way for
greater access, as does the
intake pipe and throttle
body. Just take your time
and it’s easy.
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STEP 5
With the rocker covers
removed, you can start to
see how easy this modification really is. There’s a
single bolt holding each
rocker in place – that’s it!
Grab the socket set and
start removing the originalratio rockers, being careful
not to place them with the
new ones.
STEP 6
If you’re seeing something
like this, then you’re on the
right track. With the rockers
out, remove the factory
mounting plate that sits
under the rockers and
replace them with the new
ones. We’re not sure if
there is a physical difference between them, but
it’s best to follow the
instructions. The FIT rockers utilise the original
pushrods, so they can stay
in place.
STEP 7
Before fitment of the new
rockers, be sure to coat all
friction surfaces with the
pre-lube as supplied. This
includes both tips and it’d
be a good idea to cover the
mounting surface and bearings, too. This is to ensure
lubricity at first start-up
before the oil reaches the
top of the engine.
STEP 8
When it comes time to tighten the rocker bolts to the
proper tension (11lb.ft), the
instructions specify the use
of a decent torque wrench as
shown. That said, if you can’t
afford a decent one, you can
try your luck with a Super
Cheap mini-version, or simply tighten them up with
your sockets.
The use of the torque wrench
is more to prevent over-tightening and subsequent boltsnapping, as 11lb.ft is not
overly tight – more like initial
cinching and another turn.
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145
STEP 9
Here’s the driver-side bank
completed. To the uninformed, you’d never tell
the difference, which is
kind of cool in a way.
Before refitting the rocker
covers, double-check
everything looks and feels
good by looking for irregular movement or bolt
looseness.
STEP 10
So, here’s the passengerside rocker cover back on.
You can see the throttle
and cruise-control assembly unbolted and moved
out of the way.
STEP 11
Here’s the motor basically
back together – just a simple matter of reattaching
the intake pipe, bolting the
engine cover back on and
no one would be the wiser
– except for the guys you
beat at the lights!
STEP 12
If you’re still not that confident poking around your
own engine bay, grab a
copy of your car’s workshop
manual – Haynes or
Gregory’s – and there’ll be
decent info on taking most
things apart. It’s especially
handy if you rush in and
remove all your spark leads
without thinking to mark
their corresponding firing
order first.
CONCLUSION:
With a very noticeable increase in low to mid-range poke in the test VX five-speed sedan we
fitted these to, the rears easily lit up, and on-road acceleration saw the car move off the line
faster and without any hesitation. Idle was unaffected and neither was fuel economy markedly
affected or general valvetrain operation despite the large increase in the ratio.
With the ease of installation and relatively low cost for the conversion, the FIT 1.9:1 rockers
make for a decent upgrade, and with an equally decent exhaust and cold-air intake, your
Ecotec should be flying along much faster in no time.
While we did this modification to the naturally aspirated engine, installation in a supercharged V6 would be a similar job in terms of unbolting a few various ancillaries to make
removal of the rocker covers easy.
SC
CONTACT
146streetcommodores
Forced Induction Technologies on
(08) 9472 7050 or ww.v6supercharged.com.au