Why did nhra change the cam and valve spring rule in 1985?

[art leong]

Originally Posted by Casey Miles

NHRA told the prostock teams "NO EXOTIC MATERIALS IN THE ENGINES" , why is it allowed in stock eliminator? Schubeck lifters are made from an exotic material the last time I looked. You can't buy them at any local auto parts store that I know of.
NHRA doesn't want to do their job on policing rules and for that matter what we pay for from them when we buy our memberships. NHRA is streamlining for their benefit not to have to enforce rules that should have been kept up with, like valve spring pressures. The cars in stock would not be running 1.0 under if the valve spring pressures where set to factory spec. for sure. The valve spring spec on my 302 engine was 96 lbs on the seat and 204 lbs open pressure, no way could you get the motor to 8k rpm. Now, they are changing gears at 8200 rpm.
My vote is to go back to enforcing an across the board valve spring pressure so that you have to use stock (buy in any auto parts store) lifters again.

Casey Miles
248H

An across the board number is no better than what you have now. Heavier valves need more spring pressure to control the valve. If you went back to using the specs that would be more equitable. But still not perfect.