Hey Brunelle ( comp magnum rocker problem )

[Honest Don]

https://www.hotrod.com/articles/ctrp-07 ... omparison/


“On the dyno, the high spring pressures combined with the large amount of lobe lift burned up the fulcrum area of the rockers. We had to kill both runs quite quickly, and as a result, we have very little information regarding these rockers.” Sure, Jan.


A little bit of searching shows a number of SBCs burning these things up under a variety of conditions. I did read a post about circle track guys having luck saving them by changing out the rocker ball.

I have the 1.6s and just noticed a bit of clatter on startup. I’ll report back after I work up the time and motivation to open up the valvecovers.

[pmbrunelle]

“On the dyno, the high spring pressures combined with the large amount of lobe lift burned up the fulcrum area of the rockers. We had to kill both runs quite quickly, and as a result, we have very little information regarding these rockers.” Sure, Jan.

I didn't know about Sure, Jan:
https://www.youtube.com/watch?v=_JTSAKFDSVw

That was funny.

A little bit of searching shows a number of SBCs burning these things up under a variety of conditions. I did read a post about circle track guys having luck saving them by changing out the rocker ball.

When I initially selected those rockers, this is what went through my mind:
1. The Fiero Store sells them for Fieros, so they must be good for Fieros.
2. Lots of folks on Old Europe seem to have them without issues.
3. A guy I met locally had them on his Fiero.
4. The Comp Cams Magnum rockers superficially appear to be "good-quality", having straight sides vs. the waviness of the stamped stuff.
5. I did read about stories of failures on SBCs online.
6. I had my doubts, which I expressed in the middle of this post here: http://www.fiero.com/forum/Forum2/HTML/139574.html#p4

Well, I decided to disregard points 5 & 6, and focus on points 1 through 4.

This was about an $800 CAD mistake, counting two scrapped sets of Comp Cams rockers, top-end gaskets, rocker arm studs, extra oil+filter changes to flush out the bits of ground metal.

There are folks who do good projects on a shoestring; the way I practice the auto modification hobby, it turns out fairly* expensive...

*expensive is a relative term

[The Dark Side of Will]

Development is expensive. Learning is expensive.

You can put something cheap together cheap... and then what did you learn?

[Honest Don]

Well this is interesting. Notice what’s missing?

[Honest Don]

This was the worst rocker as far as HAZ signs. I’m glad you posted your issue!


I picked up and installed a set of Ooosuh made pivots from Melling. Maybe I’ll get lucky? Even if it stays quiet, I’ll open it up over winter and inspect.

[pmbrunelle]

Wow, your used parts look almost brand-new.

Especially the pivot balls; normally they're supposed to become uniformly shiny/polished as they wear in; yours haven't even progressed to the uniform amount of shininess from a normal amount of wear-in.

I don't think you needed to change your pivots, especially as they have proven themselves good in your engine. Maybe simply re-adjusting the lifters without changing anything would have done the trick?

Ideally, to demonstrate the effect of a parameter (such as smooth/grooved), it is best to do back-to-back tests on the same car. Unfortunately, I am too stingy to buy a 3rd set of Comp Cams rockers to try this out (for now). I also don't like the idea of potentially putting more steel filings into my engine's oil.

[Honest Don]

Almost new except.....where did the grooves go?


I imagine they’re either in the filter or on the magnet.

[pmbrunelle]

Yikes, since I saw ZERO groove vestiges, I assumed you were running (originally) smooth pivot balls!

The Melling balls you used are smooth? If so, well there's our back-to-back test on the same car.

[Honest Don]

Yep, testing in progress.

[Shaun41178(2)]

So they for sure had grooves and are now gone? Or they never have them?

[Honest Don]

So they for sure had grooves and are now gone? Or they never have them?

They had grooves for sure and now are gone. There’s a little bit of visible remnant on a few. They haven’t been on very long either.

[The Dark Side of Will]

So they for sure had grooves and are now gone? Or they never have them?

They had grooves for sure and now are gone. There’s a little bit of visible remnant on a few. They haven’t been on very long either.

Seeing what the originals looked like, you can kinda see a groove remnant facing the camera on the ball in the foreground:



That's pretty F@#$ing wild.

Get an oil filter magnet on that beast...

[Honest Don]

Oh yeah, I’m a proponent of magnets on anything with a timing chain.

Think about the guys that try to run these and still have the original (aluminum case) oil pump.

[FieroWanaBe1]

I'm willing to wager that the Melling balls faire better. MADE IN USA clear on the box. Melling being a true OEM at least will have the quality department resources to keep full traceability on its parts they buy and make.
I've seen a lot of references to COMP sourcing many components from china and overseas.

Edit: removed sleep deprived rant about bad experiences with overseas suppliers.

[Honest Don]

With the move and everything else going on, I haven't been able to open the car back up and inspect. It still runs and seems quiet under the covers though, so fingers-crossed and all that.

[pmbrunelle]

Well, my Ford Ranger developed an exhaust leak between the exhaust manifold and the head... I ended up pulling a head to deal with a broken exhaust manifold bolt.

Anyway, notice the little oil-deflecting tab on the stamped steel rocker arm.

Vulcan Rocker.JPG (353.77 KiB) Viewed 1606 times

[Honest Don]

Only way to know for sure would be to run it without the covers or cut the top from one and replace with something clear.

[ericjon262]

at one point, I remember seeing oil deflecting tabs like that being popular on SBC's, but mainly so that oil doesn't go everywhere while adjusting valves.