Clearance Question????????

[Mark O'Neal]

Ok gentleman, I picked up some clay to measure the P2V clearance. Plan on doing it in the next day or two. The question I have now is the guy I bought the motor from gave me some new copper head gaskets for the motor and told me they were .040. I have never used that type of gasket. Is there anything I need to know like use them or not? Do they compress like a normal gasket?

What are you doing with the motor?

[splitdecision71]

10fore and 10aft. Checking I was at 12 degrees closest! To get it correct without the clay Bullshit!

Forgive me but can you elaborate on what your saying please? I have been a mechanic for a long time and put many engines together but they were stock engines that I didnt have to worry about. But I have never done my own race engine that is this precise. Thanks, James

The closest the valve gets to the piston is at about 5 before and 5 after split overlap. Since no cam company has had that number since Harold died...just use the clay method and skip the math.

Thank you! I picked up the clay this morning.

[splitdecision71]

Ok gentleman, I picked up some clay to measure the P2V clearance. Plan on doing it in the next day or two. The question I have now is the guy I bought the motor from gave me some new copper head gaskets for the motor and told me they were .040. I have never used that type of gasket. Is there anything I need to know like use them or not? Do they compress like a normal gasket?

What are you doing with the motor?

Drag Racing 1/8 mile

[splitdecision71]

Used clay this weekend for p2v clearance and I was good by a substantial amount just as I suspected. Went on and put the motor together. Super excited to see how this turns out. Hoping for 650 or better. Thank you all for the advice and more than that the piece of mind. Not to mention the money that I saved doing it right the first time. I will update in a few weeks with my results from the track.

[Dan Timberlake]

Some folks prefer checking piston to valve with very soft valve springs.

I always figured that method could not detect things like valve notch machining issues like valve angle, and valve centering, or piston dome to head clearance.
Clay's squishability certainly brings some uncertainties, but can provide some direct quantitative information about many kinds of clearance in the combustion chamber.