So you think you are running alot of valve spring pressure?

[Blazer406]

My brother works for a valvetrain design place... and he tests different spring/valve/pushrod combos from time to time for his own stuff on this spintron he has a small block Ford hooked to..... anyway... one of his combos he was experimenting with was a 2.10 SS intake valve... and a spring with 350# of spring pressure on the seat..... and 1000# of spring pressure over the nose!

This combo would only spin up to around 7500 RPM before valve bounce went nuts...

He has ended up with a titanium valve combo and a lighter spring.... got it turning 9100 RPM smooth as silk (on the SpinTron)......

His cam combo should have him shifting over 8000 so.... he's good...

 

[norbs]

How many minutes do the valve guides last at 1000 lbs psi though? Can he test that?

 

[Blazer406]

How many minutes do the valve guides last at 1000 lbs psi though? Can he test that?

I'll ask... I'll bet this isn't a multi-year race engine.... I'm sure it will need freshening in several fronts after one season....

 

[84gnct]

Modern Pro Stock Valve springs are 450 # on the seat and over 1200# over the nose. They get changed once they drop to 350#. They use Beryllium guides and seats. Valve sizes are over 2.5 fo the intake and 1.8 on the exhaust and a 2.300 installed height.
Non cryo valve springs last a pass or so, cryo treated Valve springs last about twice as long, depends on how good the shoe is on the shift lights and the burnout.