heavychevy357

After reading a few stories of guys having problems with the Comp Trunion upgrade I have decided to swap mine out for the he Straub Trunion Kit. I bought the car already modded. Heads are stock castings sent in to Texas Speed and they performed their 265cc CNC job, milled .030, BTR .660 springs. Well previous owner went with Comp Trunions. This setup has had about 5k miles so far and that's about the mileage I am seeing run into failures. So I am going to be switching them out. For now I am just going to post some pics of the Straub kit I received today and I'll update again in a few days when I dive into it.






Thanks,
Brenton

MTPZ06

Sub'd

Schred86

Nice move. I ditched my comp trunions after only 2,500ish miles. Show some of the worst wear marks if u can. I am curious to see how worn they are.

heavychevy357

I will definitely show the condition of the Comp Trunions. That was part of the reason I wanted to make this thread. To show off the Straub while seeing what the comp looks like and showing you guys.

heavychevy357

Well I have an update. Finished up my Trunion swap from Comps to Straub. This was a very nerve racking little project for me. This being my dream car I was pretty nervous about breaking things apart on her. I've had the Straub kit for a few weeks now but with my work schedule and family I haven't had time to dive into it until this weekend.

So.. first thing I will start off with. I DID run into a couple problems with the Straub kit. A problem with a couple bushings actually. For some strange reason when I pressed in the bushings it would make them too tight and the Trunion would bind up not allowing it to spin freely. Pressed it out and tried flipping it over with the other edge facing out; same result. So.. I tried pressing it on the other side of the Rocker body. Same result. Called up Chris @ Straub and he told me to use some emery cloth on the inside of the bushing. Did a few passes inside the bushing, wiped it off, oiled it and it worked! Not knocking the product, just noting that there was a problem with 2 of the bushings. After hitting them with the emery cloth they installed just fine.

Now.. on to the comps and the wear I noticed. On the inside of the Rocker body bore (where the bushing presses in) there were dark, wear marks on each and every Rocker(see pics below). Also not sure if the needle bearings came out due to the press(I assume so) or if they were starting to let go but some of the Comps needle bearings were falling out or the bushing.

I hope this this helps the guys who do a trunnion upgrade in the future. My thoughts.. stay away from the Comp Kit!! All the threads I read about them failing and then my own experience and personally seeing the wear after removing mine.. it's all true.

As a side note.. Use all of the assembly lube Straub provides in the kit. Lube every where haha!

Trunnion wear




Bushing wear


Rocker body wear


The Wear marks you see on the Rocker body are not actual grooves like it seems. Couldn't feel it with my finger. At least not yet. It would've eventually.

And here is a pic with the rockers torqued down post Straub kit installed!


Thanks for reading and I hope this helps out someone down the line.

-Brenton

PS: Shout out to Anthony (Aka Mordeth here on the forum), for helping me via text with this project. I asked him 100s of questions and he answered every one of them. Very helpful guy! So thanks man I truly appreciate it.

Mordeth

Glad you got her done Brenton and looks great! With the new TPMS sensors, new plugs and wires and new trunnions I think you can relax a bit and enjoy her! She is a hell of a machine you got there.

MTPZ06

What cam are you running? Still stock?

Mordeth

Pretty sure he is running a Katech K501 cam.

heavychevy357

Yes, Anthony is correct. I'm running the Katech K501 cam

heavychevy357

This is an older thread of mine but I wanted to update it. I have the heads off to rework them and took the rocker arms apart to do a visual check. Approx 10k miles were put on the stock rockers/Straub trunions. They didn’t fail per se but do show some considerable wear.

Little info on the heads. I bought the car already modded(H/C and bolt ons). The shop that performed the work for the PO was obviously shady to say the least(lots of tuning issues, poor parts combinations which I have been fixing along the way, etc)

Anywho little over a month ago I went to the drag strip to try for a personal best. Got three runs in.. each on was a new personal best, better than the previous. Went 10.66@130 mph with a 1.7 60’

So the next day I took it for a Sunday drive and something just seemed off. Little more valvetrain noise maybe? So decided to do a compression test. Checked out great. Leak down test checked out great. Wiggle test(on car) uh oh. Took the heads off and did wiggle test on the bench. Intake checked out in spec but the exhaust were out of spec(0.0049 one of the worst). Valve tips looked fine but the exhaust rocker arms were beat to ****.

On top of that the exhaust rocker arms were for an LS1! I posted a pic on Facebook of the rocker intention and someone pointed this out. I felt stupid for not realizing this. The intake rocker arms seem to be correct. The exhaust being LS1, etc means they are 1.7:1 instead of 1.8:1 (wow.. leaving some power on the table maybe?)

My point in saying that was I thought if the Straub trunions/bronze bushing showed wear it would be the exhaust rockers due to the geometry begin so screwed up. They literally sat halfway on the valve tip. Are approx 1/4” too short. Well I was wrong, both intake and exhaust bushings/trunions showed wear.

Not knocking Straub, just sharing my experience with their product. Kit looks amazing and they are great to work with if you have an issue. I think I’ll be trying CHE this go around though

on to the pics

matt95

Have you seen the Manton kit? No personal experience, just throwing another option out there.

Apocolipse

CHE has the oiling grooves for a bit better wear (this was about 5k miles)

MTPZ06

CHE also uses manganese-bronze material (same as their guide material) which is a bit more durable than the standard bronze variety.

Unreal

Any of the bronze ones are going to be a wear item, and just plan to replace them every 15-20k.

spartan8270

I’d look into running the new BTR roller bearing trunnion kit.

Unreal

Agreed. Those just came out and if you really want to go non-stock, they are a good choice. Or just OEM untouched ones.

MTPZ06

Or the COMP BSR Shaft Rocker Kit...completely different design than the comp kit you removed.