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Old 07-17-2017, 10:08 AM   #19
SSGT Mustang
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Join Date: Mar 2005
Location: Jersey
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Default Re: Hollow stem valves

Quote:
Originally Posted by James L Miller View Post
I was watching a video with Billy Godbold and Scooter Brothers and they said they built a system for a restrictor plate NASCAR engine that had 70 pound spring pressure on the seat and something like 140 pounds over the nose. I'd like to know the rest of the details on that build.
The NASCAR guys use 6mm and 7mm hollow stem titanium valves, high rocker ratios, and perfect valve train geometry, which helps them run lower spring rates. Though I'm not sure that they are as low as 70 lbs on the seat.

Nevertheless, those low spring pressures and rocker ratios don't seem to work for drag racing.
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