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FE Power Forums => FE Technical Forum => Topic started by: chilly460 on July 02, 2026, 07:32:50 AM

Title: Rocker shims
Post by: chilly460 on July 02, 2026, 07:32:50 AM

Worked on rocker geometry last night using stock non-adjustables with POP end stands.  Cam is .610" with the 1.73 ratio, which is know is pushing the bounds of the non-adjustables, but this is definitely a budget build. 

I get .592" observed lift, and same .125" sweep on the valve tip with both .060 and .075 shims.  Brent sells .050 and .080 one piece shims.  So, if you can't run a shim right on the number, is there any pro/con to running on the short side, versus the high side?  I will say shimming at .045 was better than .090, so I'm leaning towards shorter.  Also, I could get some shim material and come in right at .060, but didn't know if stacking shims is suggested, more "stuff" to wiggle when rockers start rocking is my thought there. 

Title: Re: Rocker shims
Post by: blykins on July 02, 2026, 07:42:50 AM

I've ran a lot more lift than that with factory non-adjustables, you'll be fine.

The shim thickness is marginal, it varies a hair, so it will swing a few thou each direction.

If your pattern is good with .060" or .075", you can order either a .050" or .080".  You will never notice the difference.  The .050" will probably be closer to .055".