This summer I installed a new set of Magnum Roller rocker on a stock 455 in my 442. I ran the car for 5 years with zero rocker problems.
After about 50 miles I had a valve tap so I pulled the cover and found a loose rocker. After another 30 miles the same valve was loose and I pulled the rocker and found the top of the pushrod was mushroomed.
I called Comp and they said it could be a bad pushrod and they sent me another one.
I now have less than 300 miles on them and I have five mushroomed pushrod tips.
I sent them back to Comp and the tech there said I have to check the pattern on all the pushrod to rocker arm and use different lenght pushrods to get it right.
Anybody ever heard of such a thing? I have been doing this a long time and I think I was just bulls***ted.
No where in there literature does it state that there might be a problem with this set up on a stock engine.
Thanks,
Joe

 

This is new to me but I'd like to hear others responses.

 

I am going through a similar problem on my 350. I have had the rockers adjusted 4 times and after about 30 miles they start to get noisy again. The issue I have is that the lifters are not maintaining pressure and the oil is bleeding down and not getting past the rocker. On one side 5 out of 8 lifters are bad. I now think the the lobes on the cam are going bad because the rocker travel is a lot less on some than the others. I used a comp cam and lifters and rockers. The engine will be torn down over the winter to see what is going on. I am a little upset that these parts are garbage and they were not cheap. I am not an engine builder and just know the basics. It still hurts. Good luck.

 

For starters, not really the best rocker to use BUT they should work! We prefer a "true" roller rocker!

With respect to the info Comp gave about checking the "pattern" on the valve tips, this is correct! This procedure is done on every build here!

You get the correct pattern by adjusting the lengths of the pushrods, usually done with an adjustable one. After the pattern has been established you order the pushrods! Basically speaking, the pushrods are the very LAST part ordered before the final ***'y.

Just on a side note here, you don't mention which "type" pushrods you are having issues with, but NEVER use a "welded-ball" pushrod, ever, on any roller rocker setup! This would be the "High-Energy" series from Comp.

Other vendors sell these as well under their own name/part number! Most are mfd by Elgin for just about everybody!

Thanks, Gary in N.Y.

P.S. The post above with the "cam/lobes going bad" sounds like another issue, not sure!

 

Are these installed on rocker studs? If so were they drilled for threads true to the mounting pad? Do they use poly locks? Spring installed height incorrect (coil bind)?

Other than the pushrods hitting the head I don't know. Just throwing out ideas.

 

This was sold as a complete kit which included roller tipped rockers, pushrods, screw in studs, pushrod guides and lock nuts. If the website stated I would have had to check the pattern and buy different pushrods why include the pushrods in the kit?
I would have stuck with the original ones.
I used the car for five years without pulling a valve cover so I know the problem is with the pushrod/rocker arm.
I am afraid to even use these and I might go back to the original set-up and shim the pedestals.
Thanks,
Joe

 

I had bought the same kit for my motor rep didn't tell me I had to much spring pressure to run them and this kit was more geared toward stock.kept adjusting rockers then found two dead lifters.so I called comp and snapped and asked to speak to a manger and once I told him how built my motor was he said I should have never even been sold the magnum kit.and to make things right he sent me the new full roller rockers new studs guide plates and push rods and polylocks made it better but not right had to take heads off and have them drilled and tapped for the bigger studs.in my opinion they should have paid for the extra expense but the new rockers work awesome adjusted and haven't readjusted all year.

 

Well over the winter we took off the heads to check the lifters and cam and everything was good. The push rods seemed a bit short so we changed them and adjusted everything one at a time then, with car running. They are all adjusted and not loose but the sewing machine sound persists. Pretty much everything I have seen seems to point to the fact that the Comp Roller Tips are just plain noisy. If that's the case then I can live with it. I just want to make sure I'm not hurting anything.

 

There was couple of guys here on CO that had problems with Comp cam pushrods that are included in the kit, including my self.
The same problem, after 300 miles 3 pushrods mushroomed. Ended up installing TrickFlow chrome moly pushrods. No problems after that.

 

your valves might be sinking in your head. on another note I have installed 3 sets of comp rockers, all have been noisy... check the rocker to retainer clearance. they say you should be able to slide a paper clip through there. on my currant junk I can not slide a clip through there and they tick... I need longer push rods

 

I'm perplexed why roller rockers would be noisy? Regardless of the manufacturer unless something is touching somewhere.
As far as the lifters collapsing some after sitting for awhile that is probably normal but to what extent I couldn't answer. I would imagine they should pump up almost immediately once oil pressure comes up. I'd go over those rockers with a fine tooth comb to check for any shiny spots where they may be rubbing somewhere. Retainer to rocker is a common spot.

 

I had the same problem with my 71 455. I couldn't stand the sewing machine sound, to me it sounded like a worn out engine. I tried tightening down the rockers to alleviate, and all I did was mushroom several pushrods. Off they came and they have been sitting in their box ever since. Not for me, unless someone can tell me how to alleviate the racket.

 

I have run many comp cams and had no problems with the cams themselves but I have had trouble with both the push rods and the rockers in my experience the pushrods have been the culprit also I quit using comp cams rockers and only use Harland Sharp they have a true Oldsmobile roller rocker and work perfect and I have been racing and driving them for many years Its a big expense but well worth it for peace of mind and longevity.