Zeeb

I'm in the middle of replacing the original valve springs on my newly acquired low miles LS6 (ZO6) with a set of new GM stockers, just for good measure due to the reported bad batch problems with the springs. No big deal for me to do this work. I also purchased a Comp Cams trunion upgrade kit, but I've since encountered some bad reports of early kit failures scattered about the Internet. Most of these discussions are quite old now. What is the latest thinking on the Comp kit? Still as controversial as it appears to have been in the past? My Vette will retain the stock cam and springs and may see a few hot laps from time to time - no racing or serious HPDE. Still, I'm sure to hit the rev limiter every now and then. I'm afraid that installing the kit may move reliability in the wrong direction based on these older posts. Question - given the stock lift and spring rates I plan to stick with, will the stock rockers be the safest bet? I can always return the unopened kit. Thanks much.

LoneStarFRC

Two words:

Straub Technologies

Is this one of those "old" posts/threads you speak of? It started in Feb of 2016.

http://ls1tech.com/forums/generation...nion-kits.html

I would not touch Comp trunion kit and yes, I'm speaking from personal experience.

Order from Straub directly, or one of their distributors.

vettenuts

What year is the car? GM did make a design change to the stock rockers, can't remember when but it was later in the C5 production. Eric D who was a retired GM engineer posted this information some time back, might turn up in a search.

Found it: Link

Not sure Eric D frequents the forum anymore.

Zeeb

Thanks. My car is a 2003 ZO6 built early in the year.

Zeeb

Just spoke with Chris Staub. Looks like I've been steered in the right direction. Thanks again.

neutron82

if you want your trunnions to look like this then get comp

LoneStarFRC

You're welcome..........

SaberD

Are the ones from BTR the same as the comp ones?

neutron82

as far as I know they are basically the same up to this point... I saw BT comment somewhere that they were changing the manufacturing of their kit so you might want to get in touch with him on the specifics of that, I don't know exactly what is being changed and when that change is supposed to take place... I was in contact with comp about what happened to mine and they kept in touch for a day or two and I haven't heard from them since

SaberD

https://www.corvetteforum.com/forums...r-vs-comp.html

Check post #4. interesting if this guy is right, and load of worries off my back as well.



http://ls1tech.com/forums/generation...on-inside.html

Also check post #7 here.

From what it seems, the BTR trunions haven't had had any complaints/failures.

I'm sending an email to BTR now to see what they have to say.

Zeeb

I'm done fretting about this. Going with a bushing kit and not looking back. Will keep an ear on my valve train and rest easy knowing that I'm immune from loose needles, of the GM or any other variety. Should the bushing solution turn out to have a fairly limited service life (unlikely I think for my weekender Vette), no big deal. Change em out on a Saturday morning. At least the risk of needle disaster is out of the picture. Summit will get their Comp kit back.

fmvette9

In the link provided in vettnuts post, is a picture of a stock rocker which is supposed to be of an improved design. If anyone has access to a pre 02 stock rocker and could compare it to the pictures, that would be great info.

SaberD

I got a reply from BTR saying they haven't seen the same kind of wear with their kits. I'm still going to pull one my next oil change and inspect it. If the wear issues are present, I think I'm going with the Harland Sharp trunion kit.

Zeeb

[QUOTE=SaberD;1592715678]I got a reply from BTR saying they haven't seen the same kind of wear with their kits. I'm still going to pull one my next oil change and inspect it. If the wear issues are present, I think I'm going with the Harland Sharp trunion kit.[/QUOTE

In case you are not aware, the bushed kits are in the same price range. Apparently in the recent past the only bushing option was quite expensive. I'm encouraged by the prospects for this being a safe solution. Bushings, when oiled and clearanced properly can really last. Think connecting rod small end on many hi-po applications.

SaberD

what material are the wrist pin bushings in an LS1 made of? You have an interesting point there, and those are not pressure fed either.

Zeeb

My experience to date is really with old school SBC, but the bushed rods I've purchased, in Eagle rotating assemblies, appear to have bronze bushings. Someone else can comment on LS1 rods - if they are even floating (I don't know). I'll stick by my comment about long lived bushings (if clearanced) .. and they can be splashed (vs. Pressure fed) and live a very long life.
What's a little bronze powder in your oil, if that would even happen (big if), vs. a fist full of hardened needles? That's how I see it. The presence of these kit failures in every GM based enthusiast forum (GTO, Camero, Vette...) has done it for me. My bushing kit is on order and Summit will get the Comp kit back and a $12.00 restocking fee.

Mike 92LX

UGHHHHH I have Comp cam kit in my 99Z28....I better change it fast.

Comp has really dropped the ball lately

Zeeb

From what I'm able to dig up, the failures on the Comp kit are generally not catastrophic. The Comp kit design (unlike the stock rockers which have an inner race) has the needle bearings riding directly on the trunnions, and for some reason the bearings tend to start galling and eroding the trunnion surface. Those posting with this problem have discovered the abnormal wear upon rocker disassembly. I don't think the modified rockers tend to fly apart in any way; however, the examples shown seem to be heading in that direction. I believe also, most of the posted failures associate with engines that have performance cams and higher spring rates. Perhaps that will help you make a decision on the Z28. Not an emergency, I would say. If GM had only gone a step beyond the press fit and tacked the bearing covers, or something of the sort, they would have produced the perfect rocker arm for stock to mild cams. Those GM rockers, if they stay together, are literally good for 200,000 mi. plus in a well maintained engine.

LoneStarFRC

Mike 92LX

I seen those rockers fail in stock motors too in regards to the needl bearings. I have an EPS Camshaft and dual springs. I don't drive it much but they need to be changed it seems. Lets not mention the Comp Cam failures are well. Many Vendors stopped using them