kvansic162 Posted April 28, 2010 Share Posted April 28, 2010 If I put a p90 head on N47 block using either a 1mm or 2mm head gasket, do you have to shim the towers? I do not plan on shaving the head. I want low compression for a turbo.Also any other tips on swapping the n47 head with the P90 head would be great. Thanks... Quote Link to comment Share on other sites More sharing options...
sbooth Posted May 14, 2010 Share Posted May 14, 2010 P90 cam centerline is same height as other heads although valve stem lengths may be different due to the "higher roof". Not sure about valve lengths, just thought I remember something of that nature. Shims for the cam towers are for when you mill the head to maintain that centerline height. You should use flattops of zeroish deckheight to keep compression 8.5ish with a 1mm headgasket. The 2mm headgasket will get you even lower. Round dish under a peanut shaped closed chamber is not ideal and will yield unnecessarily low compression ratios of 7.4 with a 1mm headgasket or less for the 2.I don't understand why the factory did the p90/dished combo except to make triple dog sure there was no detonation. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.