Cometic .030 head gasket
Seasoned HDF Member
Joined: Dec 2005
Posts: 5,464
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If your piston is above the cylinder at TDC, there would still be a chance the valves would clear, but it is still too tight of a squish band for a street motor (assuming the .030 hg).
BTW - For about $40 iirc, Cometic will make you a set of MLS head gaskets in any thickness. My HQ kit came with .027" gaskets, and my pistons are down the hole .005".
Zach
Road Warrior
Joined: Apr 2008
Posts: 1,899
Likes: 8
From: Aurora, IL
Deck height and piston to valve clearance are really two different things all together. You could have a -.010 deck height and still have piston to valve clearance issues with a .040 head gasket depending on your piston and cam selection.
Piston to valve clearance should be checked either way.
If you bought all this from Fuel Moto as a package, I would talk to them about it. If it is a combo they put together often, they might tell you that you dont need to check the clearance. They might know that it has more than enough clearance.
A squish check is different that a valve clearance check. You should always do a squish check if you're building a high performance motor. Too tight squish can result in piston to head interference.
Checking valve clearance is something that need to be done when you're using cams with a lot of TDC lift, and when your'e running oversize valves in certain configurations. If in doubt, check it.
Two great pages on checking squish and checking piston to valve clearance can be found on the NRHS website. The instructions are easily understood, and they've got some good pictures, too. Highly recommended.
Checking Squish
Checking valve clearance
Checking valve clearance is something that need to be done when you're using cams with a lot of TDC lift, and when your'e running oversize valves in certain configurations. If in doubt, check it.
Two great pages on checking squish and checking piston to valve clearance can be found on the NRHS website. The instructions are easily understood, and they've got some good pictures, too. Highly recommended.
Checking Squish
Checking valve clearance
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