I have a cracked valve shim. I see that there is adjustments by changing the shim to a thinner or thicker shim. Is there an easy way to figure out which size shim I need? Any info on this is greatly welcomed and appreciated.

 

Just curious, what was the symptom of the cracked shim?

 

You measure the gap between the base of the cam, ( point of cam facing 180 degrees away from the cam bucket ) then measure the shim.


EG.. the clearance is 20. the specified clearance is 15. so you need a shim that is 5 thicker than the original shim.


If the clearance is 15 and the spec is 20, you need a shim that is 5 thinner than the original shim.


The best way to measure the gap, is to take out the shims from the buckets and put them back in upside down, then measure the gap between the bucket and the back of the cam.


This way you negate any false reading from wear on the shim face from the valve stem.


How did you crack a shim?

 

Just pull the old/cracked one out and measure the edge where there is no wear.
Use a metric caliper or micrometer and get the same size or thicker/thinner if the clearance is incorrect as Andrew stated.

The exhaust cam is easy to remove for shim swap but the intake requires more work. You will need a tool to depress the 'bucket' or remove the cam. Intake cam removal is difficult because of the primary chain. The front timing cover will need to be removed.

bob gauff