Bad_AX

There is a company called RPM Engine and Machine in CA installing the Straub trunnion kit. They are going well beyond installation and precision grind the rocker tips to correct errors. They also hone the rocker bores to control tolerance between the bushing and shaft.




I think this procedure could go a long way to address the Fugly wipe patterns we see on LS7 rocker arm tips, and maybe some of the side load/deflection issues. I'll be sending my rockers to RPM.

rjacobs

Im not saying CHE does those things, but there were more things done to my rocker arms than simply them installing their bushing kit. The rocker tips had been cleaned up and I couldnt tell the wipe pattern from when I took them off. Beyond that, I dont know.

The other thing I like about the CHE kit over the Straub kit is they use spiral retaining rings vs. c-clips.

flyby763

Who did them for you?

rjacobs

did what?

The CHE bushings? CHE did as they are the only place you can get them done. They dont sell by themselves.

flyby763

WCCH has them listed as a service on their website, maybe they just send them to CHE though.

rjacobs

yes. They send them out. Anybody that "offers" them sends them to Claude.

Maybe the Straub kit is good for a lot less money, but until there are reports of guys running them for a while with no issues, I am completely happy with spending the money on CHE which seems to be a proven product. I believe the highest mileage I saw on the CHE was somebody with 40k miles and zero play, checked every 10k miles. I did a lot of research to see the long term on these before I did them.

MTPZ06

Had Kohle send mine to CHE when my car was in his shop...not sure if they were backed up, but it was anything but a quick turn around. Just an FYI...

Michael_D

Two things I did not like about the CHE rocker upgrade. 1) splash oiling, only. 2) their trunions do not register to the finished machine shoulders of the pedistals, so they walk a bit.

How does the Struab trunion mount?

C5Natie

I installed the CC trunion kit in April of 2013 and they seem to be running fine to this day in my LS3. The intake lobes of my cam have a .641 lift too with an aggressive ramp rate. I have seen no shiny metal flakes on my magnetic drain plug ever.

This makes me wonder if this is a more recent heat treatment issue with the trunions. Also I wonder what he lift specs were on the cams where the trunions were galled and also was the valvetrain geometry set correctly.

Must_Have_Z

When I had my heads redone, the builder advised me not to do a trunion upgrade no matter the manufacturer, as it's not needed...

tdeweese

My cam was large GT-21 LPE cam 243/259 with .700" lift. So for sure I was stressing the trunions, however the stock GM rockers I pulled off after 5000 miles with this cam were fine, I chose to go with the COMP upgrade due to hearing all the complaints about the stock rockers. I installed the COMPs with their installation jig and used dial indicator to ensure the axial movement was within the specified tolerance so I am certain the installation was correct. They were installed and only lasted 1200 miles and showed signs of delamination as shown in my picture. It certainly appears to be a heat treat issue. I since went back to stock GM rockers that proven to last very well with a .700" lift cam. Katech also said they have not experienced failures on rockers from LS7's 2009 and newer. I had to completely rebuild my motor due to these COMP trunions, but that's my story others may have favorable results, seems to be hit or miss.

Radical05

So my question is the numbers. Comp sold 1000 of these kits in 2015 let's say so how many people had issues 1,2,3,10? One person said 100% of the ones inspected were bad so was that 2 of 2 people making it 100%? If there were 10 out of 1000 that would not be a worry to me if there were maybe 100 or more out of 1000 then there is a trend.

Unreal

Pull one apart then report back.

Unreal

Every single person I know that actually popped them apart and looked had severe wear. Right now that is up to 5. Anyone that has taken the time to actually take one apart has replaced them after finding the wear.

I said the same thing, and I'm sure you can find post from me 2-3 months ago saying "I have 18k miles on mine, no issues, runs great" then I actually pulled one apart and it was holy crap, that is bad. Then I told a buddy here, and he did the same, his were trashed, then local shop started inspecting them on cars coming in, and finding them trashed with <5k.

Do what you want with that info.

All the snap ring grooves were filled with metal shavings, all trunions were worn at least as bad as this one. Now that this is an apparent issue, people are checking and finding more and more failures.

I'll think the question should be the other way around. Find me one example of someone with >5k miles without wear. So far that hasn't happened. Actually pulled apart and looked not just "my car runs fine after 5k miles".

MTPZ06

^^ Couldn't agree more with Unreal...show me some examples of comp trunions with no wear after X amount of miles. Until then...CHE, Straub, stock...or pony up for a roller rocker system.

MTPZ06

You've got a bada$$ build (posted in another thread) and no one is disputing that...and IIRC you have an '07; which is the year that there had been bad batches of stock rockers, so you did the obvious which is to upgrade the trunions like so many do (myself included on my '09 C6Z - CHE upgrade). But where there's smoke, there's fire. Its not a lot of money to swap the comps out for some CHE or Straub bushing kits. Believe me when I say, we're just trying to help.

Radical05

5 of 5 is not 100% sorry and I will check mine but until then there are no big stats other than a couple on the West coast unless someone can show me different. I have stats below and from the shop that did mine but again I will check to verify anyway it only takes 30 min to see one.

So 3 different sources I asked state different opinions on these trunions 2 different speed shops / engine builders and the source, so if they are so bad why are they being made and used? Summit racing has 50 5 star reviews and only 2 1 star reviews? I find this odd and does not add up so where are all the failure stats at???

Comp Cams;
Using a good oil, like Driven makes a huge difference, as well as changing the oil often. It really comes down to usage.
If the rocker arms are being used in a very high stress situation, such as high rpm, high spring pressure, competitive drag racing or road racing, then it would be best to look at a purpose built aftermarket rocker arm.
It is amazing what the factory rocker bodies with a trunion upgrade kit are capable of doing, but they will never compete with a $1300 serious set of shaft mounted rocker arms.

This is where your engine builder comes in. It is their job to advise you and use the best components in your engine that fits your budget.
It sounds like they have had good results with the kit as have many other engine builders. To run some numbers past you, we have sold between 5000 and 8000 sets(that's sets to do a whole engine or 16 rocker arms) per year since 2010. We are on track to sell about 6900 this year. I honestly feel the trunion "problem" has been a little blown out of proportion compared to the huge number of kits out there running in engines without trouble. I do question the agenda of other manufacturers and dealers on the internet, who may be trying to promote their competing product. But this is America and they are free to write whatever they want on the internet...

Thanks,
Matt
Matt Maxwell
Technical Consultant
EFI Specialist
Sales and Support

COMP Performance Group™
3406 Democrat Rd.
Memphis, TN 38118


We have not had any issues with the Comp trunnion kits and we recommend/ use them in house.
Ryan

From: Lingenfelter Performance Engineering Contact Form [mailto:sales@lingenfelter.com]
Sent: Monday, September 19, 2016 7:06 PM
To: Sales <Sales@lingenfelter.com>

zulatr

I purchased and installed the BTR version of the CC trunion kit.
Anyone have any feedback on whether this issue carries over to the other manufacturer?

BTW - when I saw the bushings, it made a lot of sense to me. The season is getting short here, I may pull a rocker and see what's up when I lay the car up for the winter.

MTPZ06

I'll speak my peace one last time and then I'm out.

Google "Comp trunion failure" and you'll find example after example after example, across multiple car forums that pertain to LS motors. More data than I needed to make an informed decision.

Google "CHE trunion failure" and you know what you find...examples of Comp trunion failures, not CHE.

outhouse

That is all we ask.


But do not expect us to stop advising others that comp trunions are crap with a high amount of failure rates blowing peoples motors up.


If those pieces of crap were honest with you they would have stated they recognized a problem and are trying to rectify their product ASAP.


But I did not see that in your little message from them. Nothing but excuses on their part with ZERO ownage of their problem.



Tell that to people replacing $20,000 LS7's.


How many failures before its acceptable?