My bottom end has recently been completely rebuilt with new bearings, bolts, etc, and the crank was polished and rebalanced. I am selecting a new cam and am wondering the max rpm range I can safely operate. Am I safe with 6500 rpm as the upper limit?
The edelbrock Preformer RPM cam has 6500 rpm as upper limit, and is not the wildest cam out there. I think there should be no problems. Valvetrain has more to say in rpm potential than the crank imo.
If your damper is a good one, you won't have any trouble. Cast cranks don't deflect much before they break (low ductility) and need a good damper (as well as balance) at high RPM. That said, 6500 should not be problem.
thanks for the info guys. I have a nice summit billet sfi approved harmonic balancer for the crank and 7/16 rocker studs with a stud girdle for the valve train. I guess I am ok. I can always advance the cam by 4 degrees to drop the peak rpm down by 400 revs if it ever becomes an issue.
I am not saying a stock crank can't be broke, but I have never heard of one breaking. The issue with 351w cranks is bearing speed. From what I have read that becomes a problem closer to 7500.