Wiped Cam Lobe? What are my options? (Page 7/7)
pmbrunelle MAY 12, 06:33 PM

quote
Originally posted by 82-T/A [At Work]:
Old post PM... but the CompCams ones you're referring to, is that THESE rocker arms?

https://www.fierostore.com/...0%20%20160&d=352&p=1

I have those too, and with my old engine, I started having issues. I was considering re-using these in my new 3.4, but now questioning if I should even bother. What kind of issues did you have? Were they seeing premature wear? Nothing re-adjusting the valve lash couldn't fix?


Thanks!



My experience is with the 1.52 ratio version of the 1.60 rocker arms you linked to (Comp Cams Magnum).

My rocker arm saga starts here:
https://www.fiero.nl/forum/...L/142133-5.html#p165
For full details, read until page 9 of my project thread.

Summary:
I destroyed two sets of Comp Cams Magnum rockers. (burned up, shredded pivot balls)
Comp Cams Magnum rockers appear to have a flawed oiling design.
Stamped Melling stock replacement rockers lasted me about 10000 km (much more reliable than Comp Cams).
It seems like the performance valve springs and installed height on the short side caused valve opening forces on the high side, which didn't help anything.
I'm running Scorpion roller rocker arms now, and all seems OK.

Don had problems with the 1.60 ratio version of the Comp Cams Magnum (same as what you linked to):
https://www.realfierotech.c...iewtopic.php?t=21767

********************************************************************************

In order of preference / perceived reliability:
1. Scorpion roller rocker
2. Stamped rocker arms such as Melling
3. Comp Cams Magnum

If your 3.4L longblock comes with stamped rocker arms, I think you might as well use them. If they don't suffice, then it might be worth the trouble to switch over to Scorpion.

I would avoid Comp Cams Magnum.

Edit to add: If you're installing a high-lift cam with stiffer valve springs, you might want to lean towards running the Scorpion rocker arms. Note that some supporting hardware is needed to install Scorpion rockers, besides the rocker arms themselves.

[This message has been edited by pmbrunelle (edited 05-12-2023).]

82-T/A [At Work] MAY 13, 12:17 PM

quote
Originally posted by pmbrunelle:


My experience is with the 1.52 ratio version of the 1.60 rocker arms you linked to (Comp Cams Magnum).

My rocker arm saga starts here:
https://www.fiero.nl/forum/...L/142133-5.html#p165
For full details, read until page 9 of my project thread.

Summary:
I destroyed two sets of Comp Cams Magnum rockers. (burned up, shredded pivot balls)
Comp Cams Magnum rockers appear to have a flawed oiling design.
Stamped Melling stock replacement rockers lasted me about 10000 km (much more reliable than Comp Cams).
It seems like the performance valve springs and installed height on the short side caused valve opening forces on the high side, which didn't help anything.
I'm running Scorpion roller rocker arms now, and all seems OK.

Don had problems with the 1.60 ratio version of the Comp Cams Magnum (same as what you linked to):
https://www.realfierotech.c...iewtopic.php?t=21767

********************************************************************************

In order of preference / perceived reliability:
1. Scorpion roller rocker
2. Stamped rocker arms such as Melling
3. Comp Cams Magnum

If your 3.4L longblock comes with stamped rocker arms, I think you might as well use them. If they don't suffice, then it might be worth the trouble to switch over to Scorpion.

I would avoid Comp Cams Magnum.

Edit to add: If you're installing a high-lift cam with stiffer valve springs, you might want to lean towards running the Scorpion rocker arms. Note that some supporting hardware is needed to install Scorpion rockers, besides the rocker arms themselves.





Thanks PM... I appreciate it. I'll look into this. The most telling thing I noticed was the fact that the oil passages on the Comp rocker arms are not angled towards the fulcrum... really poor design there. I wonder why they did that.
zkhennings MAY 19, 11:22 PM
Was going to guess O2 sensor or vacuum leak of some kind, also check grounds to motor, provides ground for all the sensors. Bad MAP or TPS also possible to cause these issues. Most other issues would cause WOT issues.