Piston Valve clearence

**tarheelsoldier** · 07-13-2012, 01:30 PM

ok... odd question. but what is the normal valve allowance on a stock piston. AKA what is cut in the piston to allow what valve size? if I do a rebuild, will the stock pistons take a cutting to allow 2.02, 2.05, or 2.08 valves? I bought my car built and he didnt have any receipts or anything to tell me what is in it. So I am assuming stock pistons.

***Fastbird*** · 07-13-2012, 03:36 PM

Not necessary unless you cam is going over .600 lift. Even the GM847 at 234/242 .575/.595 clears with ported heads and 2.02 valves.

Posted from my Rooted and ICS'd Rezound

**dawdaw** · 07-13-2012, 05:40 PM

Originally Posted by tarheelsoldier

ok... odd question. but what is the normal valve allowance on a stock piston. AKA what is cut in the piston to allow what valve size? if I do a rebuild, will the stock pistons take a cutting to allow 2.02, 2.05, or 2.08 valves? I bought my car built and he didnt have any receipts or anything to tell me what is in it. So I am assuming stock pistons.

If if were you i would tear that short block apart and rebuild the whole motor... There's no sense in putting a pile of money in the top end and hoping your bottom end will hold up... Not saying that the stock bottom end can't handle it, but it's a big what if. Plus if you plan on putting spray/boost to it, those pistons will be toast in no time. My buddies 355 lt went 9's on a $400 forged gm crank, $250 dollar scat i beams, and a cheap set of $200 dollar speed pro forged pistons with a two bolt studded bottom end.... and the motor held up for over 4 years before he parted it out... just my .02

**tarheelsoldier** · 07-13-2012, 07:55 PM

I will be rebuilding the whole motor. Just can't decide how far of a rebuild i want to go right now. Limited funds is making a stock rebuild with a decent set of heads and cam sounds real nice right about now...