Head reface question
 

What's the max amount which can be taken off the cylinder heads on a 3.2 without running into clearance problems (or any problems!) and how much of a compression ratio increase can I get by doing this? (or is it a stupid question!?!?)

any takers?

Natahn,

If you provide me your e-mail, I can send you a compression ratio spread sheet. Send me a PM.

You'll need to know your current bore, stroke, head and piston dome volumes, assume a deck height of 1.25mm unless you know what it actually is. You can play around with the numbers and see what changes in head volume (CC) can do to CR. I don't know exactly how much milling will reduce head volume CC....a machine shop can probably figure it out if you provide them the CC's.

In general, it's not wise to flycut your heads to increase compression ratio - at least on a 911 engine. The best way is to use JE pistons, or to stretch the rods. These methods are a bit less destructive to your engine. Once you flycut - that's it -they're done...

-Wayne