Rocker Arms

[Travis Miller]

Originally Posted by Pat Cook

So, if we have a cam that is suppose to have .400 lift, but the closest rocker we can find figures out to 1. 46 ratio. it would be ok to have a cam ground with a.273 lobe to make up for the rocker ratio, but if we have a rocker that actually has a ratio of 1.56 you can not have a cam ground that has a .256 lobe lift to get the lift to check legal?

Just curious.....

If you are talking about an engine that has a spec of 1.5 rocker arm ratio, the first senerio would be okay. The second one would mean you have used a rocker arm that is sold as a 1.6 ratio and that would be illegal. While the total lift at the valve retainer would check correct, the ratio would be incorrect if it were to be checked.

The difference is you have used a rocker that has altered the rate of lift as the valve is opening and closing from the original rocker arm ratio spec but hid it by meeting the total valve lift spec once the cam reaches max lift.

Travis

(Disclaimer: Opinions expressed by me on this forum are exactly that, my opinions.)

[Tom keedle]

Originally Posted by Travis Miller

If you are talking about an engine that has a spec of 1.5 rocker arm ratio, the first senerio would be okay. The second one would mean you have used a rocker arm that is sold as a 1.6 ratio and that would be illegal. While the total lift at the valve retainer would check correct, the ratio would be incorrect if it were to be checked.

The difference is you have used a rocker that has altered the rate of lift as the valve is opening and closing from the original rocker arm ratio spec but hid it by meeting the total valve lift spec once the cam reaches max lift.

Travis

(Disclaimer: Opinions expressed by me on this forum are exactly that, my opinions.)

how would that be any different from a cam being ground different?

[Pat Cook]

Originally Posted by Travis Miller

If you are talking about an engine that has a spec of 1.5 rocker arm ratio, the first senerio would be okay. The second one would mean you have used a rocker arm that is sold as a 1.6 ratio and that would be illegal. While the total lift at the valve retainer would check correct, the ratio would be incorrect if it were to be checked.

The difference is you have used a rocker that has altered the rate of lift as the valve is opening and closing from the original rocker arm ratio spec but hid it by meeting the total valve lift spec once the cam reaches max lift.

Travis

(Disclaimer: Opinions expressed by me on this forum are exactly that, my opinions.)

I am no "engine master" by any means, but is there any real power by doing that? and isn't it the same thing as the way stocker cams are ground anyway? the dwell cam verse the rpm cam?

Is there any dyno proof? just curious.....