Rocker arm ratio needed

[Directconnection]

What is the rocker arm ratio of the sohc? We have two mechanical race cams here at work and need to find out the specifics here so we can order springs...

[Warren Stramer]

Roller or slider? Roller=1.75, slider=aprox. 1.6, average across the slider face.

[Directconnection]

It's a mechanical slider. Has quite the flat nose, but using the 1.7 ratio... has .498 lift, while the other was around .422"

I just did a cheater head for the guy. 198 cfm at .550" lift with +1mm valves and the guy brings in a.422 cam replacing the .498 saying that is what he's going to run:o I guess there's a .420 lift cam rule... yet .430 is production.

Eagle rods, knife edged the crank and chamfered the CW, port the head and is now going to de-nut the thing baclk to the same level of performance, yet with a $5,000 bill.

Oh well...

So... with 1.6 ratio, I find it hard to believe he's going to install a .399" cam.

I guess we'll just measure the cam at the valve and see what we have.

[BadAssPerformance]

Roller or slider? Roller=1.75, slider=aprox. 1.6, average across the slider face.

I think this is in the NHRA spec book too...