Leyland P76 Owners 2005

Question about Pistons

The six is so much fun...not like those boring V8's.

04 July, 2005

Discussion

MICHAEL CLARKE wrote:
What fun! The six is so much fun...not like those boring V8's.
Take the valve clearances..adjustable through replacement of different sized shims..
I had no idea a P76 could have such boundless pleasures as to remove and replace overhead cams and cam carriers...
whilst doing ones best to keep track of shims the size of the old one cent piece....
not to mention grinding them down and watching the odd one fly off the grinding wheel and round the garage to who knows where...
Then replace everything all good to go, runs like a bag of s*&t...check clearances..number eight valve not closing...but but but....I spent an hour measuring, calculating, putting the pieces of the shim jigsaw together.......
Aha the penny drops...or rather the shim did when I was putting the cam carrier back on wedging in wrong place keeping valve open...off goes the cam carrier again...wheee shims a bit looser this time plopping around all over the place...awsome fun..luckily I had kept a written record of each shim, thickness, name rank and serial number...known aliasses and likely hangouts...shims in right place cam carrier back on...check clearances
again...
All back together....woopeeee she runs ...yes better than before still a bit of noise but the valve that origonaly had two thou clearance before I started is now closing properly.
Next project, replace the timing chain and check to see if the tensioner is working at all....cant wait!
The V8 owner misses out on all this fun.....how boring life must be!
(Thanks to Steve Lees at Ferntree Gully Leyland for donating a shim or two and his advice/encouragement.)
Mick

Reply

Hi Michael.
Not all V8 owners have it easy.
One of my cars runs a much modified 4.4 engine and it runs Roller
Rockers but I have stuck with the Hydraulic cam so the set up of the
Roller rockers is also time comsuming and knuckle busting. Ime sure
that Mick Lecoq and Warrewyk Willams will agree that this is one bit
of maintenance that we would rather forget as we run this idea on our
engines.
From my experience its best to stick with a mechanical cam and put up
with the rackett from under the bonnet with the rollers or don't run
them at all if using a hydraulic set up. These arent set up by cyl
firing order ie 18436572 but valve timing sequence of 1&6 at TDC
onwards to the last cyls 2 and 3. I have tried different clearnaces
but have ended up with no clearnace, but the pushrod being able to be
turn around, and the thing still is about as load as an XU1 holden
with a solid race cam. One day I will try some adjustable pushrods as
they might be a doodles too short but only if over a long period of
time affects the burning out of a valve etc. However when set up and
quiet the low down torque of these big valve heads and roller
rockers , makes the engine extremely flexible ie 3rd gear from 300 rpm
up up a steep slope with out protest from the driveline.
So you see not everbody has it easy when it comes to Leylands!
Cheers Nick
Reply to Nick from Darryl
Hi Nick,
Bit worried about your reply on the roller rockers with hydraulic
camshaft and lifters. I run 1.6 Chev SBC roller rockers with
posilocks on 7/16 ARP studs and modified SBC Manley flat guide
plates. I presume you have something similar.
You must have preload on the hydraulic lifter, adjusted with the
posilock. With the lifter sitting on top of the camshaft lobe you
finger tighten the posilock until until it nips up the pushrod
firmly. Then using a spanner on the posilock give it between a half
turn to three qarters of a turn adding preload to the hydraulic
lifter. Then lock the posilock.
If this was not done at the time the camshaft was bedded correctly it
may never quieten without a new camshaft and lifters.
I run 8.95 inch trend hardened 120 degree pushrods. These are the
correct length for my head setup, each situation may vary.
These are as quiet as the original items, and should need very little
or no adjustment as the motor wears.
Can thoroughly recommend this modification.
regards,
Darryl
Last updated
Dec, 2005
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