View single post by Judson Manning
 Posted: 11-01-2009 02:24 pm
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Judson Manning

Joined: 03-14-2005
Location: Atlanta, Georgia USA
Posts: 406

The re-grinds have a smaller base-circle to get more lift (you can't really add material to the toe of the cam), no worries, it's common practice.

If you look inside the cam buckets, you'll see there is only so much material coming into contact with the valve shim.  Go too thin with the shims and the contact point for the bucket goes from the valve stem to the upper spring seat....which is not good.

Long-term solution is to pull the head and have the stems ground another .010"-.020".  Of course grinding the valve stem too much and the shim makes contact with the upper spring seat....again not good!

Another option is to use the old-style cam tower gaskets to get another .010"-.015" clearance.  Years ago I spoke with a club member who had some metal gaskets made just for this reason.  Not perfect, but less work and money than pulling the head.