Need more P/V clearance in a BB mopar

[GTX JOHN]

I am confused.......How can you tell piston to valve clearance BEFORE
you CC Heads and know how much they will be milled. It is not unusually
to mill BB Mopar heads .060 or more to get the correct specs.
Every thousand you mill them bring them closer to piston.
How can you measure accurately piston to valve prior to finishing the heads
that are actually being used on engine

What did I misread on this post?

[randy wilson]

Originally Posted by GTX JOHN

I am confused.......How can you tell piston to valve clearance BEFORE
you CC Heads and know how much they will be milled. It is not unusually
to mill BB Mopar heads .060 or more to get the correct specs.
Every thousand you mill them bring them closer to piston.
How can you measure accurately piston to valve prior to finishing the heads
that are actually being used on engine

What did I misread on this post?

If you angle mill, it does funny things, and can give you a slight larger valve to piston clearance. I’ve also seen it stay near exactly the same. But beings you have zero valve reliefs, I don’t know how that’ll work.

[GallopinGhost]

John,

Maybe I didn't explain very well what I'm doing. The whole purpose of this exercise is to figure out how much to machine the heads. I have a finished block with the crank, 1 rod/piston, cam, head gasket, and a spare assembled head, with valves and rockers, and an adjustable pushrod. I then take P/V measurements. Then measure the valve drop on my spare head, which is the travel of the valve to the head deck. Next I compare the valve drop on my new head at the shop to mine. If the new head had .010" more valve drop, I should have .010" more P/V clearance.

The steel shim gaskets are mopar performance and are available from mancini, for $20/set. Felpro 1009 is what I'll probably use though.

Not angle milling the heads.