Rocker Arms

[Travis Miller]

Originally Posted by BRUCE PARSONS

Typical NHRA tech.....a few can interpet the rules completely different than a few hundered racers. I can't wait to see what they'll use to check with!

Bruce, rocker arm ratio is very simple to check. One only needs to know two numbers. Cam lift read at the lifter and valve lift read at the retainer. Simple math gives the ratio.

Jeff, the racer that got DQ'd did not PO the techman. I was quite calm about the situation. When the cam came up way short, I asked him where the rest of his rocker arms were. Seems he had two on the engine and sixteen in the trunk. Two from the trunk made the cam read correct at the retainer but when I checked the cam at the lifter and did the math, it came up more than the listed 1.5 ratio. His engine builder told him over the phone that any rocker ratio was allowed as long as the cam checked at the retainer. His engine builder was wrong.

For the racers following this discussion, rocker arm ratio is a spec listed in the Engine Blueprint Specifications on NHRA.com. Up until now it was something we only checked if the rockers did not appear to be correct. Now it seems that some have shown their hand and we may have to look more closely.

It's amazing what an open forum will bring to light.

Travis

(Disclaimer: Opinions expressed by me on this forum are exactly that, my opinions. And I was only letting everyone know what the rules were. I did not realize what would be exposed.)