I picked up a set of new Crane golds, but it seems like I've been stumbling across some bad news on not just the Cranes, but aluminum-bodied rockers altogether.

Do aluminum rockers deflect more than steel rockers? What is the BIG difference that would make someone pick a steel rocker over an aluminum?

Need a little help...if the majority says to use a steel rocker, then I need to send the Crane Golds back. Thanks in advance.

~Joe

 

Steel wont wear like aluminum (stress cycles) and eventually break.

 

I read about that too. It has to do with how the metal reacts to force. The steel stays rigid all the way to a certain point, then it starts to bend. The aluminum starts bending at a much lower level. So the aluminum is always flexing to a small extent, whereas the steel stays rigid.

I don't think the deflection would have anything to do with lift #s or valve float, etc, just the reliability of the rocker. The only pro to aluminum would have to be the lighter weight I would think.

Unless someone can say something else good about the aluminum rockers over steel I would always choose Comp's pro mags...

 

I guess the pros of Aluminum is that they are lighter... but the Steel pro-mags are lighter over the nose and stronger... I myself went with the pro-mags because they are rebuildable and warrantied forever if the bodies break.

 

I like aluminum for a hydraulic cam. With the relatively light springs used with a hydraulic cam, they are plenty stong enough. Longevity with these springs should be fine too. GM used them on the LT4, right? For a solid lifter cam and race level spring pressure I would go with a steel rocker though.

Rich Krause

 

steel is what i would go with. most of the mass is concentrated on the pivot point of the rocker

 

Pro mags all the way.

 

I'll be using one of the larger (236/242) XE grinds from Comp. Should I send the Crane Golds back and pick up the Pro Magnums, or will I be ok with them? I won't put many miles on the car once it is done, and will probably be a weekend/strip car.

Any more thoughts? Thanks.

 

ProMags are rebuildable by Comp, thats one of a few very good qualities about them

 

I wouldn't hesitate to use them. But if it will make you feel better, get the Pro-Mags. As I said previously, I have used both with no problems and would only say that if you are running a spring with >300-350lbs over the nose that you should stick with a steel rocker if you plan to get a lot of miles out of them. Of course, cars with >300-350lbs tend not to see many miles between rebuilds anyway

Rich

 

Comp Pro Mags are 8650 chromemoly steel, which is THREE times stronger than the 7075 aluminum used in Crane's. It's not even a contest.

If you're talking about stamped steel rockers, then you're absolutely right about them breaking.