ls1nova

So I'm having some issues with breaking rocker arms for some reason. I have a simple setup 502-AFR heads-Crane 741 cam- Comp Pro magnum roller rockers- Morel lifters.
What I did was copy the engine I built last year for my Velocity and put the pair of them in my 33 Powerplay. The new engine is the one that's giving me crap. So far I have broken 2 rocker arms. 1 was the first trip out (#7 intake) the 2nd was the this weekend (#8 exhaust). The bottom half of the rocker is breaking off.

I'm loosing faith quickly in the Comp Pro Magnums. Anyone else have any problems with these? I'm thinking I got a bad batch or something. My vavle geometry is perfect.

Thanks,
Frank

ls1nova

Here are some pics of the carnage.

ls1nova

I'm going to order a new set today. I no longer trust these. But I'm not sure what to get now. I thought these were supposed to be pretty tough.

Thunderstruck

What pushrod guide plates do you have? The guideplates need to be AFR or modified stock to make the U slot longer due to the intake valve geometry on the AFRs or the pushrod will hit the back side of the guide plate. Mine broke the guideplate so it is unlikely that the rocker arm would break but.....

I use Crane Golds no issues for 3 years with AFR 305's. One set is wide body stock from Merc and the other set is the "regular" Crane golds.

Have you been working with RMBuilder?

ls1nova

My guideplates are the ones that came from AFR. I didn't notice any scaring on my pushrod when I removed it either.
I haven't talked to Bob recently, but he was a big help with my setup last year.

Thanks for the suggestions!
Frank

Chris Sunkin

Improper pushrod length could be your issue.

ls1nova

The way I set my pushrod lenght was using an adjustable pushrod I put white metal marker compound on the valve and cycled and adjusted the length till I got the smallest wipe on top of the valve. The roller tip ended up pretty much in the center of the valve.

Jerry B

Any chance the valve springs are coil binding?

Budz Motorsports

Wow that rocker saw som heat. Make sure the pushrod is not clogged! Looks like someone was welding on the thing.
For some reason it was not getting any oil.

Chris Sunkin

Sounds like you're at least close enough on length. Coil bing- or right very close to it is the next bess guess. That would cause those stresses and the heat. Oiling issues can also contribute. I was looking at the broken side and completely missed the opposite where it's discolored. Are they all blue under the bearing?

Changing rockers won't do anything but change the color of broken rocker pieces in your collection. Those Comp rockers are about as tough as it gets.