Does anyone have experience or real world results using a 1.8:1 intake rocker with a 1.7 exhaust rocker on a 351c or Boss 302?
Thanks, Chuck
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Yes, I've used 1.8 roller rockers.
My opinion is that you are better off changing the cam for the increased lift and not risk the additional strain 1.8 ratio causes.
Some of the circle track racers like to mix them usually shortening the exhaust side but I have no experience with that combination.
Those guys are always screwing with something to make more torque out of the turns?
I have broken rocker arms studs in the past and the only difference was they broke with the 1.8 ratio.
Incidentally, the 1.7 arm is Chevy and the geometry is wrong for the Cleveland. 1.72 is what you want.
My opinion is that you are better off changing the cam for the increased lift and not risk the additional strain 1.8 ratio causes.
Some of the circle track racers like to mix them usually shortening the exhaust side but I have no experience with that combination.
Those guys are always screwing with something to make more torque out of the turns?
I have broken rocker arms studs in the past and the only difference was they broke with the 1.8 ratio.
Incidentally, the 1.7 arm is Chevy and the geometry is wrong for the Cleveland. 1.72 is what you want.
T&D rocker arms are only available in whole sizes such as 1.6:1, 1.7:1, 1.8:1. You can't purchase a T&D 1.73:1 rocker arm, they don't make one. Even their Cleveland rocker arm is 1.7:1.
Mixing ratios is a useful tool in some situations. For instance, if I were installing a Crane HR216 roller cam I would use 1.8 rocker arms on the intake side, and 1.7 rocker arms on the exhaust side. In fact I have a set of eight 1.8:1 rocker arms on the shelf for that reason, but I haven't used them ... yet.
Mixing ratios is a useful tool in some situations. For instance, if I were installing a Crane HR216 roller cam I would use 1.8 rocker arms on the intake side, and 1.7 rocker arms on the exhaust side. In fact I have a set of eight 1.8:1 rocker arms on the shelf for that reason, but I haven't used them ... yet.
Thanks for the replies guys. I was thinking slowing the exhaust down, and less lift, might lead to some gains. A friend that has tried over 100 cams in Boss 302s and stroked Boss 302s swears that making the int lift about .600 and the exhaust about .560 leads to gains. Any thoughts on the matter?
Thanks
Chuck
Thanks
Chuck
Yes, that is exactly what I have seen done with 351c circle track cars. Seems like going to 1.6 on the exhaust increases torque.
quote:Originally posted by c9zx:
... A friend ... swears that making the int lift about .600 and the exhaust about .560 leads to gains ...
Chuck, I always encourage experimentation ... the split ratio rocker arms seems less expensive than grinding custom camshafts to test the theory. So go for it, please share with us the results of your experimentation.