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deck milling


89IROC&RS
02-03-2004, 11:32 AM
hey guys, anyone know the max safe ammount you can mill off the deck of a stock GM small block chevy before hitting water jackets or upsetting the geometry of the heads and intake??

1992RS
02-03-2004, 09:44 PM
Well there's more than just worring about the watter jackets and heads and shit, it's also woring about puting a piston through your heads. I personaly would only get enough milled off to make it true agian. I think any machinist will tell you the same. I think I went .020 off the deck on the 383, but that's actualy a lot of you think about. But I'm not sure exactly, call a machine shop they should know.

89IROC&RS
02-03-2004, 09:51 PM
yeah, i was only lookin to take off like .010inches, im havin some trouble gettin a 10.4:1 compression out of my 302, and that hundredth of an inch is worth like 5cc's of combustion chamber volume. 10.4 is about the highest iron heads will run without detonation, so of course, im pushing 10.4:1 ;) trying to maximize quench and minimize combustion chamber surface area. im not really worried about pistons through my heads, id still have a good .035 or .025 inches down in the hole, with a .015in gasket, giving me .050 inches or .040inches total clearance between the piston crown and the head. which is pretty close to the smallest safe ammount of clearance most builders reccomend. what can i say, i like pushing the envelope :)

89IROC&RS
02-03-2004, 09:55 PM
oh and no im not building it yet, just crunchin numbers and shoppin part numbers, getting all my facts strait so i order the right parts. i still have to have my heads cc'd so i can get an accurate measure of what im working with, i have heard anywhere from 61cc to 64cc vortec heads, which im having heavily worked over, so i should probly have them done, and then cc'd, and then go from there, ah the joy of engine design, so many variables, so little time :)

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