How to determine shim thickness for preload?
How to determine shim thickness for preload? 
05-16-2005, 04:25 PM
#2
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Do a search for a post by me entitled pushrod calculator.
The proper pre-load on the Comp Rs is a debateable, but a bit more than recommended seems to work really well.
Shimming will also affect your rocker/valve tip wipe area so be careful.
Ben
The proper pre-load on the Comp Rs is a debateable, but a bit more than recommended seems to work really well.
Shimming will also affect your rocker/valve tip wipe area so be careful.
Ben
05-28-2005, 05:43 PM
#3
TECH Resident
If you call the Comp tech guys they will tell you only .002-.004 preload with the engine hot. They think that is .008-.010 with a cold engine. That's about 1/4 turn on a shaft rocker. Nobody really knows how much these LS1 engines expand. I have Comp Rs and I have adjusted 2 times and they still make more noise than a solid lifter. Sounds like the valve train is falling apart.
05-28-2005, 05:59 PM
#4
Like Ben said, shims ARE NOT the proper way to adjust pre-load. However, shorter or longer push-rods are. It just depends on how much your heads are milled and if your running an aftermarket cam. You can use a shim for some minor tweaking, but I wouldn't use any more than .015-.020". Anything else will mess up your valve swipe.