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Exhaust valve back side radius
Posted: Sun Dec 09, 2018 4:24 pm
by dhidaka
What is the influence the backside radius of exhaust valves on flow/performance/HP-torque? Try 10* nail head and 20* tulip and 26* tulip. For example a 2-valve hemi with 60* exit turn and 45* seats. I assumed the default would be some sort of tulip, but the new PipeMax shows many really Hi-Po engines using 12* nail head.
Re: Exhaust valve back side radius
Posted: Sun Dec 09, 2018 4:48 pm
by Newold1
My favorite setup is a 35 degree back cut on a 24 degree tulip backside on the exhaust valve with a radius as the bottom cut of the the exhaust seat. No radius on the backside of the valve. Really seems to make great lower lift flows on the exhaust side.
I only sbc's, LS's and bbc's, so I won't comment on other heads.