LS Rocker Arm Bearing/Trunion Comparison
05-02-2013, 12:28 PM
#81
After reading about these trunnion wear issues, I'm hoping it's just due to over exertion due to crazy big cam lift and stiff springs, but hard to say that's the root cause at this point. Could be a combination of factors, not just one big smoking gun.
I have PAC 1518 springs with stock LS6 cam in my '02 C5Z, so the loads on my rocker arms are way less (~320 lbs max @ 0.550" lift) than some of these guys who are having trunnion wear issues with somewhat radical setups. Still, I'd like to know if anyone with the trunnion kit in a stock LS6 has seen any failure or wear issues.
Last edited by ZeeOSix; 05-02-2013 at 12:35 PM.
05-02-2013, 12:46 PM
#82
That would be cool ... highly appreciate that. Didn't see what your cam/spring setup was specifically - I'm assuming something more than stock LS6.
After reading about these trunnion wear issues, I'm hoping it's just due to over exertion due to crazy big cam lift and stiff springs, but hard to say that's the root cause at this point. Could be a combination of factors, not just one big smoking gun.
I have PAC 1518 springs with stock LS6 cam in '02 C5Z, so the loads on my rocker arms are way less (~320 lbs max open valves) than some of these guys who are having trunnion wear issues. Still, I'd like to know if anyone with the trunnion kit in a stock LS6 has seen any failure or wear issues.
After reading about these trunnion wear issues, I'm hoping it's just due to over exertion due to crazy big cam lift and stiff springs, but hard to say that's the root cause at this point. Could be a combination of factors, not just one big smoking gun.
I have PAC 1518 springs with stock LS6 cam in '02 C5Z, so the loads on my rocker arms are way less (~320 lbs max open valves) than some of these guys who are having trunnion wear issues. Still, I'd like to know if anyone with the trunnion kit in a stock LS6 has seen any failure or wear issues.
05-02-2013, 12:51 PM
#83
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straight from the Comp Catalog
The LSK Series has been designed with enhanced characteristics from our latest professional drag racing profiles. These
have excellent ramp quickness. They are VERY hard on parts and not generally recommended in street applications!
have excellent ramp quickness. They are VERY hard on parts and not generally recommended in street applications!
Last edited by 96lt4c4; 05-02-2013 at 12:57 PM.
05-02-2013, 12:55 PM
#84
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When I said XER I meant LSK, went back and changed my post. Still an aggresive lobe not as much as LSK though.
Last edited by 96lt4c4; 05-02-2013 at 01:02 PM.
05-02-2013, 05:15 PM
#90
Has anyone point blank asked Comp Cams if they know of any batches of the trunnion kit not receiving correct materials and/or heat treatments? I'll have to look, not sure if there is a batch number on the trunnion kit box or not. Kind of like PAC had a bad batch of valve springs a while back and they narrowed it down to a few bad manufacturing batches.
DietCoke - about when (month & year) did you purchase the trunnion kit that went bad on you?
DietCoke - about when (month & year) did you purchase the trunnion kit that went bad on you?
05-02-2013, 06:02 PM
#91
Thanks ... I bought my kit in June 2011, so it was probably manufactured in Mar 2011. Guy at Comp Cams said there should be a date on the box when they were made, but no batch number.
I called Comp Cams and talked to their Tech Dept about the wear on the trunnions where roller bearings are. They said they have not had many issues reported back on their trunnion upgrade kit. They have no data to support any bad QA or bad batches ever being made. Of course, I hear stuff like this when things like this start to pop up, to later find out there was some kind of issue from the manufacturer. Guess time will tell.
Way too many factors could be involved in an issue like this, but overall it sounds like seeing wear like you have seen has not been reported to Comp Cams and is rare to be seen from car owners. Of course, who really looks unless there's a problem that makes you investigate more?
I called Comp Cams and talked to their Tech Dept about the wear on the trunnions where roller bearings are. They said they have not had many issues reported back on their trunnion upgrade kit. They have no data to support any bad QA or bad batches ever being made. Of course, I hear stuff like this when things like this start to pop up, to later find out there was some kind of issue from the manufacturer. Guess time will tell.
Way too many factors could be involved in an issue like this, but overall it sounds like seeing wear like you have seen has not been reported to Comp Cams and is rare to be seen from car owners. Of course, who really looks unless there's a problem that makes you investigate more?
02-11-2014, 08:28 PM
#92
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Comp trunion failure also Mine look exactly like this after 25,000 miles. Lunati .660" lift springs .651" on the intakes. I was running prc's for a while. I did have a couple valve stem seals come off the guide and get shredded. I attributed this trunion failure to contamination from that several months back. But now I am not so sure that was it. I guess I am going to replace them to get me going again but hate to just repeat this in 20,000. I hear livernios claims the stock bearings are superior.
02-11-2014, 09:26 PM
#94
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It would be good to hear from people who HAVE ACTUALLY CHECKED theirs to see if their trunions look like this. You can remove the rocker and check for play between the trunion and bearing. Mine started squeaking because the actual rocker was touching the trunion. Take a magnet and run it in the top of the heads where the oil returns are and see if it comes out furry. I'm sure there are lots of them out there right now with this issue. Not going to chase a warranty claim, but I am going to let comp know about it. Check your trunions that you think are bulletproof and post results.
02-11-2014, 10:46 PM
#96
02-14-2014, 01:31 AM
#98
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any surface where a bearing runs on has to be suitably hardened;
you can test it by seeing if you can leave a file mark on the undamaged portion of the trunion bearing surface.