destroyerSS

iTrader: (2)

what is safe and what is the minimum that is allowed? Thanks

SPANKY LS1

iTrader: (24)

I think that .080 intake and .100 exhaust is what most people consider acceptable clearance.

Shawn

Chris@AP-Engineering

iTrader: (-2)

.100" on the intake and .120" on the exhaust are safe!

.050" on the intake and .070" on teh exhaust are minimum.

SPANKY LS1

iTrader: (24)

Hey Chris, do good valve springs make .050 more acceptable than bad valvesprings? For example, if Comp 977s are used, can you get away with tighter P to V clearances than if Comp 987s or a lesser spring would, simply due to the fact that 977s are less likely to float?

Shawn

Chris@AP-Engineering

iTrader: (-2)

Spanky,
You are correct. If you have a good spring and can control the valve well, you can get away with very little P to V. Bad thing is the less clearance you run the more chance of hitting the piston, because springs do wear out. If you are going to shallow up your clearances then you need to keep a eye on your spring pressures as the springs get mileage on them.

Wolfee

iTrader: (3)

Just an FYI, I spoke with my engine builder ( Mcgunegills in Muncie IN) yesterday about high RPM valve float and he told me the BEST lifters by far that he's tried are the Cranes, he said they had very little variation at high RPM compared to low to moderate RPM. He is now building a spec engine for a circle track series that I used to run in and he is VERY reputable. I know that "normally" .090 on the exhaust is the very least you want to see with piston to valve clearance. Normally you only need to worry about the exhaust clearence. Seems to be a pretty diverse topic though, everyone has an opinion. Just thought I'd chime in here.
Scott

destroyerSS

iTrader: (2)

So if i end up with a .085 p/v with comp 977 springs i should be safe