DaleMX

iTrader: (4)

had a 3 angle valve job done to my head while they were off the engine. The shop also took .008 off to flatten them out. In the bill there is a detail on the shim kit ( .060 ) used. The springs are set at 90 lbs closed (1.81) and 240 lbs open (1.31). I did a compression check after installing the heads and saw that 3 cylinders have zero ( 0 ) compression. Just as a quick test I loosened up the rockers a bit and got 175 lbs of compression. My question is if I just shim up the rockers will that mess up the geometry? How can I calculate the exact amount to shim?
<img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

<small>[ September 30, 2002, 09:28 PM: Message edited by: DaleMX ]</small>

JWRENCH

Double check to make sure where your cam is at so your sure you don't have any lift involved. then I'd loosen them one at a time and narrow it down to one or the other (intake/exhaust), then I'd run the bad one up to the highest lift point and check the spring with a feeler gauge against a good one to see exactly where it's at as far as height. then go from there...

DaleMX

iTrader: (4)

The problem is that the 3 angle valve job has set the valve deeper into the head. That coupled with the 8 mill cut on the surface has brought the valve up so high that the pushrods are now too long. I think I'm going to shim up the bar that holds the rockers about .030 at first with some T6061 stock I've got laying around. I guess I really dont know how to set up height correctly to insure that the preload is correct. Trial and error I guess.

Tin Indian

You know what I would do. I would just change rods. Comp Cams manufactures LS1 rods in .050" incriments.

Comp Cams pushrods P/N 7950-16 (7.350” length) (thats .050” shorter than stock) is what I would put in it.

In fact, you can save a few bucks by buying the Thunder Racing rods. Same as the Comp Cams, but slightly cheaper.

<small>[ October 01, 2002, 12:16 AM: Message edited by: Kimchee and Rice ]</small>