when do you need to cut valve reliefs in the piston
when do you need to cut valve reliefs in the piston iam building my setup soon and need to know at what size cam will i need to cut the pistons. I'll be running ls6 heads or 5.3 heads. Is there a cam lift to cut the reliefs.
thanks , i was looking to run around 580 lift, with some 5.3 heads, maybe around 11.1 com , its also a stock bottom end with flat top pistons. other stuff unknown now just getting a idea where iam going with it.
10 Second Club
Joined: Nov 2002
Posts: 1,471
Likes: 3
From: Berkeley, California
Maximum lift is not a deciding factor because it does not occur when the piston is near TDC. Max lift is only indirectly a factor because high-lift cams tend to have longer durations than lower lift cams. The most critical factors are the intake-valve-opening (IVO) and exhaust-valve-closing (EVC) points. Thunder Racing’s T-Rex cam’s IVO is 12 degrees BTDC and EVC is 13 degrees ATDC. These values can be considered the most extreme for safety with stock (unmilled) heads and no valve relief. As the others have said, there are many considerations and it is best to check whenever there is doubt.
Last edited by Gary Z; Jan 12, 2008 at 12:58 PM.
what iam think about doing, need to check cost first, but i think i might just have a custom cam made or i could check price on just getting the pistons cut now so i can run most cams
whatever you choose craygn, if your PTV is to close for comfort, you can always flycut the pistons in the car.
