KVROD

Hey All,
I am in the process of changing heads and entire valvetrain on my 2000 LS1. I have read several different sources that reference the use of shims to get the correct wipe pattern on the valve, then determine the correct pushrod length. It is my understanding that the rocker bolt is an 8MM so I have gone in search of shims. Mcmaster Carr uses inside and outside diameter and thickness for their shims. Obviously the ID should be 8MM right? What is the OD, I measured the Harland Sharpe rocker arm mounting base and it looks to be about 16MM but Mcmaster Carr has no such. I guess I am less than because this seems like something that should be a no brainer but I can not find any reference anywhere as to the shim size to use and I dont mean thickness as that has to be determined, I mean ID and OD of the shim. Please help a morron.

LS1MCSS

iTrader: (18)

Not sure if Scorpion shims will work, but they do sell them. Scorpion offers shims in .020” thickness, part number
SCPRS.020

wildcamaro

iTrader: (15)

Why don't you shim the spring base? Are you trying to get correct seat pressure or just trying to get proper valve train geometry with roller rockers? (I don't think rollers are worth the headache personally with the minimal gains and constant tuning of them even though I have seen them used successfully, it's just not for me)

KVROD

I thought the rocker shims would be easy to find. Shimming the springs will not effect the wipe pattern as the height of the valve will not be affected, only the spring would be affected using spring shims, correct?

Darkman

iTrader: (2)

You are correct. You might try McMaster-Carr for shims.

wildcamaro

iTrader: (15)

Ok I see what ur sayin your right...

vettenuts

iTrader: (4)

Are these stock rockers or aftermarket? I used some McMaster shims for my Yella Terra rockers. For stock, Ford makes shims that will work under the OEM rocker stand. So, it depends on your setup. Also, careful on the need for shims, sometimes the stock rockers need to be lowered with an aftermarket cam and then the rocker stand must be machined. The aftermarket stands are better for this requirement.

KVROD

I am using Harland Sharp non adjustable rockers on CNC LS6 heads. I have not torn things down yet and am just trying to be proactive so when I do go to assemble things I dont have to hunt down shims. I am also installing a Comp Cam 54-424-11 cam. I must be slow, everyone references McMaster Carr but I don't find shims for the ID and OD required, forgeting about thickness. I am assuming I need an 8mm Id as that is the size of the rocker bolt and I measured the OD of the Harland Sharpe mount(for lack of better term) and I can not find anything even close in the metric or regular shim listing. Do you remember what siz ID and OD shim you used from McMaster Carr? Thanks for the input.

KVROD

I gave Scorpion a call. Sounds like their shims should work great. They are 8mm .020 thick and come in a pack of 36 so they can be stacked if necessary. Thanks for the lead, I appreciate it.

vettenuts

iTrader: (4)

I used washers to figure out how thick of a shim I needed. Then I ordered the shims. They were SAE shims but very close to the metric dimensions. Here is a link to how I set up my rockers, the last paragraph provides the dimensions you can use to look up the parts in McMaster.

Link to write-up