greenturtle05

Need a little help. I need to know how much will i need to mill a set of vortec heads, on a 350 with flat top pistons,and stock head gasket for 10:1 compression?

skinny z

10:1 is possible without milling. With a true flat top piston that has a valve relief volume of about 6cc, the 64 cc (assumed) chamber will yield 9.89:1 also assuming a piston below deck of .025". That's using a .025" gasket. Put a .015" shim gasket in there and you get 10.14:1.

greenturtle05

whats the thickness of the stock head gasket? also i already have the heads milled .010. what should my compression be as of now? i was thinking about taking another .010 off when i get my springs installed.i cant remember the piston valve relief cc.

skinny z

You'll have a prety hard time figuring out if you have 10:1 if you don't find the data needed to do the calcualtions.
A .010" milling of the heads will shrink the chamber about 1 -2 cc's.
I couldn't tell you what the thickness of the stock head gasket would be. I'd only be guessing. You should also find out what the valve relief volume is. Without it, you'll never know what the CR might be.

greenturtle05

found the info on the pistons http://www.jegs.com/i/Sealed+Power/844/L2256F/10002/-1

cuisinartvette

Here you go, play with this and youll get closer.
(sounds bad, huh lol)

Youll find cc in pistons makes the biggest difference in the compression not the deck height but if they are already installed probably the most expensive/most work lol.

Youll need to know the exact CC in your combustion chamber that will help. I can show you a real easy and cheap way to do that if you like. You can also figure intake runner volume etc without having to spend 120 on a burette. Its pretty accurate, within 1 cc or less


http://www.rbracing-rsr.com/compstaticcalc.html


When choosing pistons read the mfrs footnotes if they dont show them ask
Some will rate the c.r. at 0 deck, some at .025 in the hole, etc.