roller rocker arm installation instruction needed
Thread Starter
6th Gear
Joined: May 2004
Posts: 6
Likes: 0
From: jeddah
roller rocker arm installation instruction needed
I have installed a set of compcams roller rockers 1.52:1 ration to my c4 lt1 engine, i have tried 2 different preload settings , 1st was 1/2 turn after zero lash but it was noisy in high rpm , 2nd was 3/4 turn after zero lash but engine start uneven idle and tends to hisitate a bit, i need to know what would be the best way to adjust the roller rockers in my car and to get the max performance out of it, as GM service manual is saying that one complete turn after zero lash is the right seting? and i think it is a lot and might result in compresion lost . any thoughts :crazy:
Burning Brakes
Joined: Dec 2003
Posts: 770
Likes: 0
From: Madison Mississippi
Re: roller rocker arm installation instruction needed (khalid)
GM used 1 full turn on the lt-4's, on the lt-1 3/4 turn should be close enough to run perfect. I always suggest to adjust them while the engine is running. This way you don't have to be an expert and the results are always perfect. Do one side at a time running and back them off one at a time; until they clatter, then tighten them until they get quiet (zero-lash) then 3/4 turn. It took me a couple of tries myself to get it right too. Now, mine are quiet as stock. You can jam cardboard along the bottom of the head for a splashshield if you want to contain the mess. Good luck and enjoy the extra performance. :thumbs:
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: roller rocker arm installation instruction needed (khalid)
I wish I had a dollar for every time I've written this, but here goes again:
The REAL TRICK to properly adjust lifter preload is to make absolutely sure that the lifter is on the base circle (heel) of the camshaft lobe when the adjustment is made.
If the lifter is on the cam's ramp, the adjustment won't be correct.
You'll want to preload the lifter .030" (+/- .010").
There are several different ways to accomplish this; each guy seems to have his preference, as do I. All of them will work, if done correctly.
I even saw one post from a guy who recommended putting a dial indicator on each rocker.
Basically I've used the same procedure since Hector was Pup, having first used the "engine idling" method. The procedure I now use is the same one that the Big Boys running NHRA events use and is the one recommended in the catalogs of CompCams and Crane, etc.
I posted the method I prefer in the 'TOOLS' "Tech Tips" section in case you want to take a look.
Jake
[Modified by JAKE, 10:01 AM 5/13/2004]
The REAL TRICK to properly adjust lifter preload is to make absolutely sure that the lifter is on the base circle (heel) of the camshaft lobe when the adjustment is made.
If the lifter is on the cam's ramp, the adjustment won't be correct.
You'll want to preload the lifter .030" (+/- .010").
There are several different ways to accomplish this; each guy seems to have his preference, as do I. All of them will work, if done correctly.
I even saw one post from a guy who recommended putting a dial indicator on each rocker.
Basically I've used the same procedure since Hector was Pup, having first used the "engine idling" method. The procedure I now use is the same one that the Big Boys running NHRA events use and is the one recommended in the catalogs of CompCams and Crane, etc.
I posted the method I prefer in the 'TOOLS' "Tech Tips" section in case you want to take a look.
Jake
[Modified by JAKE, 10:01 AM 5/13/2004]
Safety Car
Joined: Dec 2002
Posts: 3,655
Likes: 24
From: Charleston SC
Re: roller rocker arm installation instruction needed (RUBYREDVETTECARD)
GM used 1 full turn on the lt-4's, on the lt-1performance. :thumbs:
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