Adamsy87

Hey guys I am planning on a rebuild on my engine....This is the cam i am planning on running.

Crane Powermax cam: Duration @ .050 Int. - 222 deg Exh. - 230 deg Gross lift .509/.528

My question is has anybody ran this cam, and if so will the factory springs and rocker arms be suffecient?

Any help would be awesome!
Thanks, Adam

Ed Maher

No, that cam will not even come close to working with stock valvesprings, way too much lift.

Adamsy87

..ok thanks....

Has anybody ever tried using a factory rocker arm on a cam with this much lift? Or does that have anything to do with the lift? Any opinions?

Don Christensen

The slots in the rocker will cut into the studs because the rocker is travelling farther with the high lift cam. Buy either long-slot rockers or roller rockers. I am 51 years old, and have reached the point where anytime I build a performance engine, I use roller rockers and a stud girdle. You have to buy tall valve covers, but it is worth it because with valve train stabilized, nothing ever breaks and you can rev the snot out of it!!

Two other items:

Your pushrods won't last. When they bend, you will hear a tapping noise and think you have a bad lifter. It is a bent pushrod. Buy some chrome-moly steel pushrods.

The bottom of the valve retainer may hit the top of the valve seal and possibly even the top of the valve guide. This can cause your motor to "suck a valve", which is both loud and expensive. Check this by installing a retainer and keepers (but not a valve spring) on any valve. If the clearance between the bottom of the retainer and the top of the valve seal is less than .550", then pull the heads and have the valve guides cut down. Low profile valve seals ( for sale on eBay) can help a lot, but the guides have to be machined with a cutter (available from Comp Cams) and an electric drill.


Your are never too old to go fast - Good luck and have fun !!!!!!!!!