Piston to valve clearance whats safe?
Originally Posted by Chris@AP-Engineering
.100" on the intake and .120" on the exhaust are safe!
.050" on the intake and .070" on teh exhaust are minimum.
.050" on the intake and .070" on teh exhaust are minimum.
Shawn
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.
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.
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
Scott
