Comp Trunnions after 12K Miles
04-24-2017, 04:49 PM
#41
Staging Lane
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I just swapped out the Comp trunnions for the CHE kit. The comp trunnions didn't show any wer (yet) but needles did fall out as a pressed the old bearings out.
05-03-2017, 01:58 PM
#42
I can't remember if my roller conversion was from comp or somewhere else, had it done back in '07 I think. I have about 15K miles on my motor, and checked the rockers a few days ago while I had the motor out anyway to change the clutch and look things over. All rockers but one had slop, one rocker was pretty locked up. I took one of the loose ones apart, and it looks like the outer race of the bearing is just falling apart. The rollers inside look like they can almost stack on each other! So, I'm probably going with new rockers and get the head freshened up.
05-28-2017, 09:42 PM
#46
I'm going to go ahead and throw some fuel on this fire. I have three sets of Straub kits on my cars, but in the process of upgrading an ls3, I decided I wanted to keep the stock units stock and just build a spare set. I asked a friend for a set of ls3 rockers, he had a set with the comp kit with around 5k miles on them from running a turbo 416. I was excited to take them apart from all I'd seen. Keep in mind, I already have 3 sets running Straubs bushings because I believe in the bushing.
What I found when I removed the comp kit? Nothing. I was seriously disappointed, because I was looking forward to justification. Nope, not even a bad scratch.
So where I'm going with this is, there has to be a threshold for where these comps go bad. Like, a certain spring pressure, or maybe cam lifts, I don't know. All I know is its not strictly the crappy metallurgy. And until we understand the problem, we're doomed to repeat it with the Straub kit.
Just my thoughts, but id like to see if anyone knows specifically what's causing this issue.
What I found when I removed the comp kit? Nothing. I was seriously disappointed, because I was looking forward to justification. Nope, not even a bad scratch.
So where I'm going with this is, there has to be a threshold for where these comps go bad. Like, a certain spring pressure, or maybe cam lifts, I don't know. All I know is its not strictly the crappy metallurgy. And until we understand the problem, we're doomed to repeat it with the Straub kit.
Just my thoughts, but id like to see if anyone knows specifically what's causing this issue.
05-28-2017, 09:49 PM
#47
A few reasons
1 some possibly werent the comp kit but the cheap chinese stuff
2 lack of break in additive in the oil or lube on the rocker trunions before dry firing and waiting for oil to be pumped up to the top
3 poor quality oil/lapse in changing oil
Those are a few ideas or reasons thst are hardly touched on. So many have turned this into an internet urban legend where every set fails. Ive said before not every set fails. Ive personally seen 3 checked that showed zero with well more than 20k miles. Others customers have checked again with zero issues.
1 some possibly werent the comp kit but the cheap chinese stuff
2 lack of break in additive in the oil or lube on the rocker trunions before dry firing and waiting for oil to be pumped up to the top
3 poor quality oil/lapse in changing oil
Those are a few ideas or reasons thst are hardly touched on. So many have turned this into an internet urban legend where every set fails. Ive said before not every set fails. Ive personally seen 3 checked that showed zero with well more than 20k miles. Others customers have checked again with zero issues.
05-28-2017, 10:56 PM
#48
When my car gets back on the road it will be a daily driver, and I don't plan to tear down the engine any time soon without due cause. If the trunions cause a problem, or I have the valve covers off and get curious, you all will be the first to know. And yes, I will be using break-in oil to start.
05-29-2017, 11:18 AM
#49
FormerVendor
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China Parts. HI All, MANY HERE sell China Parts then put that part in their "named" box.
This IS against US Law
The China Part can be easily identified.
One common case is the "First Gen" item fails, NOT recalled, then the Second Gen part, the same part, is an improved item.
This case is observed above, with POOR Heat treat in the first GEN item.
My case could be supported by measurement, a Rockwell of both GENS.
The saddest fact is a large company is MORE guilty of this practice.
The smaller quality companies, CHE is one, do not make this error.
Lance
This IS against US Law
The China Part can be easily identified.
One common case is the "First Gen" item fails, NOT recalled, then the Second Gen part, the same part, is an improved item.
This case is observed above, with POOR Heat treat in the first GEN item.
My case could be supported by measurement, a Rockwell of both GENS.
The saddest fact is a large company is MORE guilty of this practice.
The smaller quality companies, CHE is one, do not make this error.
Lance
05-29-2017, 11:55 AM
#50
Lance,
So you're saying CHE is selling inferior Chinese products as their own products? Possibly meaning their bushed rocker upgrade?
So you're saying CHE is selling inferior Chinese products as their own products? Possibly meaning their bushed rocker upgrade?
05-29-2017, 06:42 PM
#52
A few reasons
1 some possibly werent the comp kit but the cheap chinese stuff
2 lack of break in additive in the oil or lube on the rocker trunions before dry firing and waiting for oil to be pumped up to the top
3 poor quality oil/lapse in changing oil
Those are a few ideas or reasons thst are hardly touched on. So many have turned this into an internet urban legend where every set fails. Ive said before not every set fails. Ive personally seen 3 checked that showed zero with well more than 20k miles. Others customers have checked again with zero issues.
1 some possibly werent the comp kit but the cheap chinese stuff
2 lack of break in additive in the oil or lube on the rocker trunions before dry firing and waiting for oil to be pumped up to the top
3 poor quality oil/lapse in changing oil
Those are a few ideas or reasons thst are hardly touched on. So many have turned this into an internet urban legend where every set fails. Ive said before not every set fails. Ive personally seen 3 checked that showed zero with well more than 20k miles. Others customers have checked again with zero issues.
05-29-2017, 06:54 PM
#53
Stock rockers are built completely different. You cant compare them.
They are known on a few forums for failure. Im not sure our microcosm reaches to all around the world or even the country. People still use them and the cheap summit/chinese ones every day.
The 26918 springs were notorious for failure, then the scorpion rockers, then the yella terras, then the ls7 stock valves, then the ls7 sleeves, then...whats the next big thing that will blow over? Scorpions and yella terra are still used, 26918s are sold and so is everything else that had buzzworthy failure in the ls world.
Trying to pin down one or 2 actual causes is the main issue. Esp if comp uses these or this design in their other rockers like the promags or ultra gold etc.
They are known on a few forums for failure. Im not sure our microcosm reaches to all around the world or even the country. People still use them and the cheap summit/chinese ones every day.
The 26918 springs were notorious for failure, then the scorpion rockers, then the yella terras, then the ls7 stock valves, then the ls7 sleeves, then...whats the next big thing that will blow over? Scorpions and yella terra are still used, 26918s are sold and so is everything else that had buzzworthy failure in the ls world.
Trying to pin down one or 2 actual causes is the main issue. Esp if comp uses these or this design in their other rockers like the promags or ultra gold etc.
05-29-2017, 08:28 PM
#55
I sometimes feel that the reputation of Comp reunions failing is something that only goes as far as LS1Tech. It can be a bit of an echo chamber here at times, as with pretty much all forums, and I haven't heard anyone else complain about them in the real world.
That said, I still favor the bushings by design
That said, I still favor the bushings by design
05-30-2017, 07:11 PM
#56
Probably one of the big issues that is being overlooked in these discussions is who actually manufactured the trunions. I bet Comp does not even make them, and Summit definitely does not make theirs, and Straub doesn't make theirs. They are sent out to an outside machine shop. If we are all lucky, the shop is reputable and the same shop is used, but with Summit and Comp, that is probably not the case.
You should have seen the crappy part I got from McLeod last year. I have seen high school kids make nicer parts than this POS. I called and complained. They sent me another one. It looked better, but like the first one, it was about 28 HRc and should have been closer to 50 HRc. The lowest bidder gets the job in most of these scenarios.
You should have seen the crappy part I got from McLeod last year. I have seen high school kids make nicer parts than this POS. I called and complained. They sent me another one. It looked better, but like the first one, it was about 28 HRc and should have been closer to 50 HRc. The lowest bidder gets the job in most of these scenarios.
05-30-2017, 09:19 PM
#57
11 Second Club
iTrader: (3)
Probably one of the big issues that is being overlooked in these discussions is who actually manufactured the trunions. I bet Comp does not even make them, and Summit definitely does not make theirs, and Straub doesn't make theirs. They are sent out to an outside machine shop. If we are all lucky, the shop is reputable and the same shop is used, but with Summit and Comp, that is probably not the case.
You should have seen the crappy part I got from McLeod last year. I have seen high school kids make nicer parts than this POS. I called and complained. They sent me another one. It looked better, but like the first one, it was about 28 HRc and should have been closer to 50 HRc. The lowest bidder gets the job in most of these scenarios.
You should have seen the crappy part I got from McLeod last year. I have seen high school kids make nicer parts than this POS. I called and complained. They sent me another one. It looked better, but like the first one, it was about 28 HRc and should have been closer to 50 HRc. The lowest bidder gets the job in most of these scenarios.
06-01-2017, 09:38 AM
#58
Staging Lane
Thread Starter
A few reasons
1 some possibly werent the comp kit but the cheap chinese stuff
2 lack of break in additive in the oil or lube on the rocker trunions before dry firing and waiting for oil to be pumped up to the top
3 poor quality oil/lapse in changing oil
Those are a few ideas or reasons thst are hardly touched on. So many have turned this into an internet urban legend where every set fails. Ive said before not every set fails. Ive personally seen 3 checked that showed zero with well more than 20k miles. Others customers have checked again with zero issues.
1 some possibly werent the comp kit but the cheap chinese stuff
2 lack of break in additive in the oil or lube on the rocker trunions before dry firing and waiting for oil to be pumped up to the top
3 poor quality oil/lapse in changing oil
Those are a few ideas or reasons thst are hardly touched on. So many have turned this into an internet urban legend where every set fails. Ive said before not every set fails. Ive personally seen 3 checked that showed zero with well more than 20k miles. Others customers have checked again with zero issues.
1) possible, they came from TSP but I can't be sure where they got them
2) motor was broken in on joe gibbs break-in oil. I also have an accusump accumulator so the motor has never has a dry start in it's life.
3) I have run LS30 and it has been changed more than regularly lol.
06-01-2017, 09:46 AM
#59
TECH Senior Member
^^^^^^ sounds airtight to me.......^^^^^^^
06-01-2017, 10:15 AM
#60
I sometimes feel that the reputation of Comp reunions failing is something that only goes as far as LS1Tech. It can be a bit of an echo chamber here at times, as with pretty much all forums, and I haven't heard anyone else complain about them in the real world.
That said, I still favor the bushings by design
That said, I still favor the bushings by design
Probably one of the big issues that is being overlooked in these discussions is who actually manufactured the trunions. I bet Comp does not even make them, and Summit definitely does not make theirs, and Straub doesn't make theirs. They are sent out to an outside machine shop. If we are all lucky, the shop is reputable and the same shop is used, but with Summit and Comp, that is probably not the case.
You should have seen the crappy part I got from McLeod last year. I have seen high school kids make nicer parts than this POS. I called and complained. They sent me another one. It looked better, but like the first one, it was about 28 HRc and should have been closer to 50 HRc. The lowest bidder gets the job in most of these scenarios.
You should have seen the crappy part I got from McLeod last year. I have seen high school kids make nicer parts than this POS. I called and complained. They sent me another one. It looked better, but like the first one, it was about 28 HRc and should have been closer to 50 HRc. The lowest bidder gets the job in most of these scenarios.
Last edited by 99 Black Bird T/A; 06-01-2017 at 10:28 AM.