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

[X-TECH MAN]

Originally Posted by Billy Nees

I agree with you completely that with the advent of "CAD" camshafts there have been great strides in "Stocker" performance potential BUT it is still at a cost! No matter where you increase the opening and closing rates on the cam the valve MUST follow the ramp and the rate of opening or closing. It still comes down to a compromise. When and where ever you increase the speed of the valve event you have to have a spring rate that will allow it to follow the lobe. So you will STILL need better lifters, pushrods, springs etc. to get the job done. And you still have to spin the motor accordingly.

Might as well build a Super Stocker. Roller lifters cost less, roller rockers are less prone to breakage, Your going to sling the snot out of the engine with the rules the way they are so use better stronger parts and the heads and intakes are ported anyway and probably cost less from not having to hide what you do to them......lol.