I'm trying to have a head (N42) rebuilt. I want to have the old seats replaced and have a 3 angle job on the valves. The machine shop said he would need to have the specs to do the job properly. Mainly he was concerned with the valve height, how much should the valve portrude at the top of the head and where do you measure it from? Also the maximum amount the head could be shaved before having to use shims on the cam tower.

Can anybody help me here?

Thanks

from all the information that I have read .030" is the max that you should remove with out shimming the towers. My engine was set up this way and now has 38k on it and the new cam is looking fine . There is a member Phred he is the head guru , give him a post. :classic:

Thanks, the head I have has already been milled .010" and it looks like it's going to need atleast another .020" to get it cleaned up. I was going to try to find another head in better condition but in case I can't I wanted to be ready for this one.

Hi Ed,

I don't know the answer, though the 30 does sound like a familiar number..

You may want to call Riter Restoration in East Rochester. A sponsor and member of ZCCR, Barry Brown should have extensive knowledge you can tap. (585)385-4151

good luck, Jeremiah