When attempting to raise the compression ratio, what is the consensus on milling the head or decking the block? What are the pros/cons of each option?

I've always had my own opinion but I'd like the benefit of other's thinking on the matter.

Thanks
Mike


msimpson@millenicom.com

ok pops, you already know what im gona tell ya! deck it, deck it , deck it!

beardliz@msn.com

I've had good luck milling heads, just for convenience since I didn't pull the shortblocks out of the cars when I upped compression. So far I've done angle mills of 0.100" intake/0.200" plug side, and 0.080"/0.180" with no trouble. This gives you a little smaller diameter combustion chamber ("closes" it a little). In the future, I will probably do a combo of decking and milling to keep more material in the head lower deck, although I haven't seen any ill effects in 70k combined miles (50k, '68 Dart, 20k '64 Dart). Just make sure to calculate, then measure (after milling), the comb. chamber cc's and/or deck fill volume so you can calc. your compression ratio. The angle mill changes the angle of your header (and intake) a bit so you might have to think about that, but it is pretty slight.

Happy building,

Lou