Trunion "Upgrade" Failure
I assure you it is far far more than you can imagine. Whether rockers, springs, or lifters.
It is true that the delphi/ls7 lifters used to go back in, but i venture to say that is only due to cost. Had 1 or 2 other lifters been cheaper? Id expect them to be the norm. Will you see a gain in quite a few performance builds with a higher quality lifter? Without a doubt i say yes. Were they (ls7) a great lifter otherwise? Yes. The difference is the same in spring quality and other parts.
I should hopefully have some good options soon on some normally overlooked parts as well, but ill just leave this as a teaser.
I think it is much more than just an across the board issue.
Mr Urban has put these through their paces much more than anyone else really could but his attention to detail and not just using xx vanilla brand whatever.
I think valve weight and stability make alot of difference, based off of the records i have been keeping on nearly any reported failure.
Since the CHE bushing floats, i've wondered if it can rotate for more even wear, but i could see them doing the same thing as the other kits as well. So, i don't know.
Last edited by Johnny_M; Dec 10, 2019 at 07:54 PM. Reason: Add more information
I wonder if maybe this isn't a result of people using the newer low zinc oils? I was told to use higher zinc oil in my cammed LS1.
Last edited by wannafbody; Dec 10, 2019 at 10:24 PM.
The Best V8 Stories One Small Block at Time
https://www.briantooleyracing.com/bt...kit-tk002.html
Hopefully some time within the next couple of weeks I'll have time to take apart one of my trunnions (CHE) and we can see how they're holding up. They've got about 8000 hard miles on them with my Torquer V2.
Last edited by Bob570; Dec 11, 2019 at 11:23 AM.
bronze is a better option than steel since it is softer and particulates will potentially will do less damage in an engine. no needle bearings to vomit, as well. the downside, of course, is how fast they wear out.
lastly is just going with aftermarket roller rockers. more expensive and time consuming option to get correct, but better.
https://www.briantooleyracing.com/bt...kit-tk002.html
Hopefully some time within the next couple of weeks I'll have time to take apart one of my trunnions (CHE) and we can see how they're holding up. They've got about 8000 hard miles on them with my Torquer V2.
bronze is a better option than steel since it is softer and particulates will potentially will do less damage in an engine. no needle bearings to vomit, as well. the downside, of course, is how fast they wear out.
lastly is just going with aftermarket roller rockers. more expensive and time consuming option to get correct, but better.
https://www.briantooleyracing.com/bt...kit-tk002.html
Hopefully some time within the next couple of weeks I'll have time to take apart one of my trunnions (CHE) and we can see how they're holding up. They've got about 8000 hard miles on them with my Torquer V2.
Obviously from all the pics and theory and actual engineering, the bottom of the trunion takes the most load. Thats where the wear starts and usually is only localized there. I like the idea of using a break in assy lube, oil additive, or oil itself to help in combating this from the beginning. On any setup.
The entire trunion on our rocker kits are 5120. Having such a small shaft to take alot of the load on a rocker seems like a bad idea from that link, but maybe its ok. .
The comp metallurgy we found was lacking in many aspects.
For the differences between the 2 alloys here is a good representation article. Just so people dont get caught up in numbers and have no idea what is what. The needle bearing itself is still the issue. It will usually cause a wear pattern because it only rides in one place. Again use of a break in supplement is a good idea.
https://www.makeitfrom.com/compare/S...Chromium-Steel
The only difference there is the tsp. Its a 1.72. When you factor in actual rocker deflection, they come out to ~1.7 rar. Adding weight with any other rocker style over the valve doesnt help, especially if using a heavy valve already. It may not cause float or other situations but you can watch it hit an rpm wall on the dyno and wonder why. Most of the time youll just see it plateau but still carry some.
I have seen many higher ratio rocker arms also have issues with pushrod clearance/rubbing etc on the pushrod holes. So double check that as well.
I wonder what lift he was running?
Guess it's time to throw these out and go for a different design when the time comes.









