Milling heads; how much change in CR

[Gary B.]

Can anyone give me an estimate of how much my current 11:1 compression ratio would change by either a 10 thousands or a 15 thousands thickness taken off the heads on my L79 engine?

Thanks,

Gary

[Rob A.]

Re: Milling heads; how much change in CR

Most shops will insist on milling heads, saying that they are just going to "clean them" up so they won't leak. With the excellent head gasget material available today that is not a concern. If they are not warped, do not have them milled. There is no advantage to it, except for the engine shops to charge you.

[Rob A.]

Re: Milling heads; how much change in CR

Another problem with milling the heads is that it can change the fitting of the intake manifold, causing you to need it milled also for proper fit.

[Gary B.]

Re: Milling heads; how much change in CR

Rob,

I'm not considering milling my heads, I'm considering buying a set of heads that have already been milled.

Gary