Shim under Bucket setup
 

Hey all,

Just wondering, how does one go about setting lash on a SUB setup? A friend of mine posed that question to me and I really didn't know how to answer. :hustler:

re: the last bullet-
I never did mine with cams torqued. I did one valve assembly at a time with the cam laid in position. Just got the shim close but over and wet ground to fit by sticking it on the end of a valve and using a standard machinist's wet stone grinder. This process was per the engine builder and I never had a problem.

This is excellent information, thanks guys. Is there any suggested range to keep it within?

Am I to assume you did not have your valve springs in place during this process?

I had my cylinder head assembled. The other cylinder's valve springs would have lifted the camshaft off the head if I did not have the caps torqued down.

If stock cam, go to the tightest side of the factory valve lash spec on the 99 or later head. The exhaust side is a tad looser than the intake side.

I actually went a tad tighter than factory spec to get a little more lift and duration. It has been a while since I had a stock cam with my SUBs, so I do not recall exactly what it was. I had gotten this advice from the folks at Mazda Motorsports. You need to be real confident that the measurements are right.

If aftermarket cam, go by what is stated on the cam spec sheet.

Yes- springs are in, bucket/shims are not, except for the bucket/shim assembly being checked.

1. Remove all the shims/buckets
2. Install shim/bucket assembly
3. Check/set lash
4. Remove and install next assembly
5. Rinse and repeat

Removing all the other shims/bucket assemblies allow you to roll the cam into the position you need it to check that valve assembly without interference from the others.

Of coarse, it all makes sense now.

I guess either way will work. I think on a bench your method might be better, but if doing the operation with the motor in the car, my method would at least keep you from bending over so many times.