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Has anyone else had problems? This is my 3rd set in 30,000 miles...The bearings keep wearing grooves in the trunion...I am a 15 year machinist with a shop and tested them on my Rockwell tester. They came in at 50Rc, a little low..
They were definitely installed right. I have PSI springs. Mild Katech cam. I run good Brad Penn oil. And I now believe these MIGHT have been the culprit that toasted my motor 20k miles ago..
Just curious what other peoples experiences are. Thanks Derek
Trunion on left is first set trunion on right is second set
just ordered 3rd set. And all trunions look the same
The trunion upgrade was highly recommended by advanced induction for my heads cam setup two months ago. Actually had several different people recommend the upgrade instead of using aftermarket rockers.
I'm interested to see if others have had issues with the upgrade as well.
Could it be the springs? I know you mentioned a katech mild cam, but mild due to low duration, lift, lsa, etc? I know those numbers can be misleading. The lobe ramp rate may be aggressive, like an lsk or lsr too. Just some food for thought.
Also, i read that some of these good oils contain a lot of zinc zddp? But some don't do to well on shear pressure...something along those lines.
What lifters, and are you sure that you are running around .080" of valve lash pre-load with the valve bolts torqued to 22ftlbs?
Also, what valve springs are you running, since as pointed out, the cam lobes may be more aggressive that you think.
The only other thing that comes to mind is the mistake that AMF had when they first bought Harley Davidson, being that the bearing materiel and the bearing raceways for the wheels where both made out of like types of steel, which caused the bearings to galling seize and lock up, even though the bearing where correctly greased.
The trunions are 8620, so now it just a mater of finding out what metal the needle bearings are made out of (best guess, 52100 chrome steel). http://www.google.com/patents/US20140261269
In my first setup I had an lsr lobe with dual springs and stock valves... and the cam/trunions went to **** and ate the motor...I am not sure which one happened first or they both just had their own problems...So I rebuilt the motor with same style cam.. dual springs..SS valves..rebuilt trunions...lunati lifters and then the axles came out of 5 of the lifters...
So I called Jason at katech and he recommended this cam with milder ramp rates. And went with hollow valves.. PSI springs and comp cams short travel link bar lifters...
And rebuilt trunions...
Now 8,500 miles later I am still having just trunion issues...
And as for the trunion material, yes using dissimilar metals is a must and would imagine chromoly rollers are standard...I was looking at the stock bearings and the rollers are encased between two 60+rc bearing housings. They wear great but have failure issues of their own
OP............this is common place with heavy pressure valve components. The parts wear more frequently, however, this is very common with the CC upgrade kit. You can Google it and get many blogs about it.
Seen several comp upgrades fail. Typically snap rings breaking, but I've seen this too. Honestly I'm all for stock rockers. They just work. The failure rate is far lower than anything I've seen aftermarket that is <$1000. Only thing I would recommend over stock is a full out shaft setup (Crower, T&D, Jesel).
Well sir you make a very valid point
I have been toying with the idea..
I tried the google and hadnt found anything...I dont usually post on here
Thanks
I think this is one of those mods that is easy for vendors to push out of fear, and make an easy $200 on. You see a lot of people with them from vendors pushing them.
I think this is one of those mods that is easy for vendors to push out of fear, and make an easy $200 on. You see a lot of people with them from vendors pushing them.
i have a 230/234 612/598 114+2 cam and ported AI 243 HEADS. Would you recommend purchasing new oem ls2 rockers(currently have trunion upgrade installed w cam/heads 300 miles ago)? I have Brian tooley .660 springs. Not sure I want to spend 1000 for shaft mount on a car that maybe sees a doz 1/4 passes a year and rarely sees much WOT on the street unless it's the only reliable option. Thanks
Seen several comp upgrades fail. Typically snap rings breaking, but I've seen this too. Honestly I'm all for stock rockers. They just work. The failure rate is far lower than anything I've seen aftermarket that is <$1000. Only thing I would recommend over stock is a full out shaft setup (Crower, T&D, Jesel).
I agree the stock rockers are still the best. Searching other forums it seems this "upgrade" fails more than stock rockers.
Originally Posted by Unreal
I think this is one of those mods that is easy for vendors to push out of fear, and make an easy $200 on. You see a lot of people with them from vendors pushing them.
I did some more researching and found all the failures you spoke of...I have come to some conclusions of my own and am going to do some R&D...beins I dont want to spend big coin going back to stock and I already have the new set......I believe oil starvation is the problem...if you look at the stock trunions/bearing, oil can easily enter.
So I will make 2 very small oil slits(roughly.010") on the top of the trunions(both sides) about 30 degrees cw and ccw that goes down into the corner and protrudes into the race about .050" and angle it 45* to the bearings...being there is no load up there it shouldnt be anything but an upgrade...This will allow oil to pool and run on the race and rollers...
And after some research I am going to change oil...this is a great independant oil test I found...probably one of the best unbiased tests I have found on oil http://speedtalk.com/forum/viewtopic.php?t=30483
Thanks for the oil analysis link. Spent a lot of time on bob is the oil guy forum when I had my 99z28 a few years ago. German Castrol syn was the go to oil when you could find it. I've switched to red line street oil for the h/c. Good to see it's in the outstanding category while having a high(2000) zinc/phos level.
Using Comp Ultra Gold rollers here. The were on my previous build and moved to my new one They are pushed fairly hard and I have not had one issue with them. I would use them again if doing it over.
FAIL Comp cams trunion upgrade
