Hollow stem valves

James L Miller · 07-15-2017, 10:58 PM

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.

SSGT Mustang · 07-17-2017, 10:08 AM

Quote:

Originally Posted by James L Miller

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.

07-15-2017, 10:58 PM	#1
James L Miller Member Join Date: Apr 2005 Posts: 494 Likes: 6 Liked 25 Times in 16 Posts	Re: Hollow stem valves 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. __________________ Mopar 2 Ya!