roller rocker arm broke

[washeduptoo]

We broke a roller rocker last night, replaced it and engine ran good. My question is what do you think caused this, a couple of months ago we broke a push rod on same cylinder that caused some valve damage etc, got it fixed. I'm just concerned since it was all new and it was the same cylinder. Thanks

[ford396]

I have seen this scenario twice in my racing experience. Both times I traced it to too much lash. Both times after failure I found my lash too loose on other rockers as well. This came after setting rockers cold and not rechecking due to being in a hurry. Yea I know this is not something to not take the time to do, but s**t happens. I hope this helps you in your situation. Sometimes the toughest thing to do is to determine cause of a failure.

[Graff Spee]

Under full lift, check for valve retainer to guide clearance. Check for coil bind. Did you crush the guide seal?

[let-r-eat]

What cylinder? The inner two on each bank/ especially passenger side imexperiences will hang valve up in the guide due to heat. Only takes a split second of creating lash, snap pushrod lifter or rocker.

All good ideas above as well.

[stockcar5]

what brand of rocker arm was it?

[Egoracing]

Screw in or press in studs?? Press in check the stud for height to make sure it is not coming out. Also check the threads on both, if the threads are pulled then the nut may not be able to hold on like it is supposed to and it will work loose.

[washeduptoo]

I'm not an engine person, my brothers are and after it broke push rod, engine builder did the work so I'm not sure what brand but they're different then the other engines we have. I'll get the information.
I'm pretty sure they were set cold and probably weren't checked after hot.
It was the #1 cylinder, the 1st one you come to and it broke right in the middle.
Its got 7/16 screw in studs I think. Will check height and threads.
I found it odd it was the same cylinder as the push rod and with 4 races old rocker. Thanks for the help.

[fast_crew]

As stock car mentioned what brand of rocker? Was it the Exhaust pushrod that broke and now the intake rocker? Or same valve even?

[washeduptoo]

It was a comp cam ss rocker and it split from the push rod end to the center where the stud is. It was the exhaust valve and the same one that the push rod broke on. Thanks

[fast_crew]

I would think the retainers have to be hitting the top of the guide or spring is coil bound at full lift, Those are some very tough rockers. They are guaranteed against breakage, so don't buy another out of pocket call and get a replacement.

[washeduptoo]

Thanks for the information, I think the engine builder is handling the problem with the rocker. Thanks to all for the help.

[parrot69777]

Comp Cams stainless rockers are junk and also the heaviest rocker arms there are. Had a new set of them on a 406 with a roller and broke 3 of them over the course of a season. Put on a new set of Lunati's aluminum rockers.....never had another problem.

[Graff Spee]

Before I started running shaft stuff, I had a set of Crower stainless rockers. They never gave trouble.

[stockcar5]

i've never had trouble with the comp stainless rockers. i run crowers now and they seems better built than comps.

[fast_crew]

Ran a set of comp steel rockers for 5-6 seasons in a circle track car, never a problem, even lived through a few broken rocker studs.. Now running 1.7 comp/1.5 crower steel rockers for 2 seasons and no problems.