Robust Trunion Upgrade. Data Speaks.
Thread Starter
Teching In
Joined: May 2017
Posts: 8
Likes: 0
Robust Trunion Upgrade. Data Speaks. Is there a robust trunion upgrade for the stock rocker running .600 lift with a dual spring?
There is a lot of discussion with no definitive answer (I read the 40pg straub thread). I am looking for pictures or data saying that the Straub, CHE, BTR, or Comp kit HAS (not I think it will) hold up on a car that will see city/ highway driving for 40,000+ miles. Show me pictures, give me numbers and prove these. Data doesn't lie.
What is the set it and forget it trunion upgrade?
There is a lot of discussion with no definitive answer (I read the 40pg straub thread). I am looking for pictures or data saying that the Straub, CHE, BTR, or Comp kit HAS (not I think it will) hold up on a car that will see city/ highway driving for 40,000+ miles. Show me pictures, give me numbers and prove these. Data doesn't lie.
What is the set it and forget it trunion upgrade?
Joined: Mar 2007
Posts: 1,141
Likes: 48
From: Saskatchewan, Canada - where arguing "DA" is for the slow and weak...
In a performance engine? None. Doesn't exist. The onus is on the owner to maintain his engine.
That being said the real answer is the OEM setup with compromises made to lift, duration, spring pressure, and engine operating speed. I pulled apart a set of 250,000km stock trunnions and there was next to no wear indicated in them - and this was a B4C LS1 so you know it has more run hours than the mileage indicates.
That being said the real answer is the OEM setup with compromises made to lift, duration, spring pressure, and engine operating speed. I pulled apart a set of 250,000km stock trunnions and there was next to no wear indicated in them - and this was a B4C LS1 so you know it has more run hours than the mileage indicates.
Joined: Mar 2007
Posts: 1,141
Likes: 48
From: Saskatchewan, Canada - where arguing "DA" is for the slow and weak...
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0
Brett Foote Joined: Mar 2007
Posts: 1,141
Likes: 48
From: Saskatchewan, Canada - where arguing "DA" is for the slow and weak...
BTR LS ROCKER ARM TRUNNION KIT FOR LS7 AND GEN V LT1/4
https://www.briantooleyracing.com/bt...ls7-30115.html
EDIT: Before I **** off on this well beaten subject. I do find it odd that no one has sourced an existing caged needle bearing with an inner race that fits over the stock rocker shaft. I mean it isn't like Comp and friends started making their own bearings, these parts are being sourced from somewhere. For example: http://www.schaeffler.com/remotemedi.../nrb_us_en.pdf
http://www.schaeffler.com/remotemedi.../prg_us_us.pdf
http://www.skf.com/ca/en/products/be...ngs/index.html
http://www.skf.com/ca/en/products/be...ngs/index.html
But, I suppose we are all guilty of letting others do the thinking and legwork for us - it is just easier that way.
https://books.google.ca/books?id=909...20race&f=false
Last edited by mOtOrHeAd MiKe; May 5, 2017 at 04:22 PM.
They use a cast in stand like the ls7 heads so valvetrain geometry is different.
There is a reason you cant use the "crane spring tool" on ls7 or gmpplsx cyl heads. the springs sit so far down it doesnt even compress them.
You cannot compare them PLUS they would only be a couple years old....so not nearly the wear and tear on them vs an 00 camaro.
There is a reason you cant use the "crane spring tool" on ls7 or gmpplsx cyl heads. the springs sit so far down it doesnt even compress them.
You cannot compare them PLUS they would only be a couple years old....so not nearly the wear and tear on them vs an 00 camaro.
Last edited by tech@WS6store; May 5, 2017 at 04:33 PM.
TECH Resident
Joined: Apr 2010
Posts: 926
Likes: 18
From: Central Texas
I got a trunion upgrade kit from Michigan Motor Sports, Good quality and easy install, comes with a plastic sleeve that holds the rollers in place until the trunion is pushed into the bearing. Worked slick..
It could be attributed to no assy lube used or the lube being too thin.
Possibly a good idea to have use a break in additive to help the surfaces break in just like old school lifters etc.
Just a thought, but im pretty sure alot were dry fired and just ran.
Possibly a good idea to have use a break in additive to help the surfaces break in just like old school lifters etc.
Just a thought, but im pretty sure alot were dry fired and just ran.
The stp i understand. The mobile not so much. For install id either use redline or Joe Gibbs in both the bearing and on the trunion. I DID originally type shaft...but MAN did that sound a bit too awkward for a car forum!
Anyway if it were already assembled would be the harder part. That would require the soaking you implied but id not soak it in any reg or synthetic oil. Id look at the joe Gibbs break in oil or the numerous break in additives out there now. Not rotella or vr1 though.
Just my .02
Anyway if it were already assembled would be the harder part. That would require the soaking you implied but id not soak it in any reg or synthetic oil. Id look at the joe Gibbs break in oil or the numerous break in additives out there now. Not rotella or vr1 though.
Just my .02
Just as I figured. Wonder if we are seeing a rash of failures in Gen Vs from increased valvetrain demands too? The OEM stuff is really good when used within its designed limitations - if it ain't broke, keep upgrading it until it is.
BTR LS ROCKER ARM TRUNNION KIT FOR LS7 AND GEN V LT1/4
https://www.briantooleyracing.com/bt...ls7-30115.html
EDIT: Before I **** off on this well beaten subject. I do find it odd that no one has sourced an existing caged needle bearing with an inner race that fits over the stock rocker shaft. I mean it isn't like Comp and friends started making their own bearings, these parts are being sourced from somewhere. For example: http://www.schaeffler.com/remotemedi.../nrb_us_en.pdf
http://www.schaeffler.com/remotemedi.../prg_us_us.pdf
http://www.skf.com/ca/en/products/be...ngs/index.html
http://www.skf.com/ca/en/products/be...ngs/index.html
But, I suppose we are all guilty of letting others do the thinking and legwork for us - it is just easier that way.
https://books.google.ca/books?id=909...20race&f=false
BTR LS ROCKER ARM TRUNNION KIT FOR LS7 AND GEN V LT1/4
https://www.briantooleyracing.com/bt...ls7-30115.html
EDIT: Before I **** off on this well beaten subject. I do find it odd that no one has sourced an existing caged needle bearing with an inner race that fits over the stock rocker shaft. I mean it isn't like Comp and friends started making their own bearings, these parts are being sourced from somewhere. For example: http://www.schaeffler.com/remotemedi.../nrb_us_en.pdf
http://www.schaeffler.com/remotemedi.../prg_us_us.pdf
http://www.skf.com/ca/en/products/be...ngs/index.html
http://www.skf.com/ca/en/products/be...ngs/index.html
But, I suppose we are all guilty of letting others do the thinking and legwork for us - it is just easier that way.
https://books.google.ca/books?id=909...20race&f=false
TECH Senior Member
Joined: Jul 2009
Posts: 8,031
Likes: 661
I checked into that. The cost isn't really cost effective. What we did was take the trunion and manufacture it out of 52100. Then we heat treated the ends where the bearing rides and ground the surfaces. They have about 20k miles on them so far with no wear whatsoever. One of the larger manufactures (Comp) should be able to get a double race bearing made to their specifications pretty cheap for the volumes they buy. The companies I visit will make them with ease.
Is there a robust trunion upgrade for the stock rocker running .600 lift with a dual spring?
There is a lot of discussion with no definitive answer (I read the 40pg straub thread). I am looking for pictures or data saying that the Straub, CHE, BTR, or Comp kit HAS (not I think it will) hold up on a car that will see city/ highway driving for 40,000+ miles. Show me pictures, give me numbers and prove these. Data doesn't lie.
What is the set it and forget it trunion upgrade?
There is a lot of discussion with no definitive answer (I read the 40pg straub thread). I am looking for pictures or data saying that the Straub, CHE, BTR, or Comp kit HAS (not I think it will) hold up on a car that will see city/ highway driving for 40,000+ miles. Show me pictures, give me numbers and prove these. Data doesn't lie.
What is the set it and forget it trunion upgrade?
Stock rockers no issues have ran over 130,000 miles with .581 lift XE-R cam, Comp Cams 987 dual springs on TEA heads. Also 30,000 miles on same rockers when car was bolt on only. Total of 160,000 miles on stock rockers.
An aggressive camshaft profile will fail the OEM rocker before it will fail the bushing trunnion kit. For those that are going aggressive on cam profile you need to go to a full roller rocker and a lifter with a .750" wheel since 95% of all profiles are designed for a .750" wheel diameter.
To date we have a little over 40K miles on 1 set of the bushing trunnions in a period of 16 months in a driving school corvette. I have several customers with over 10K miles on trunnion kits. I have airboat engine builder customer with over 300 hours on 4 LS3 engines with sustained 4400 rpm trips for 3 to 5 hours at a haul.
Again, the bushing trunnions will give out at some point, BUT when they start to fail they will tell you and warn you with increased valve train noise. When a needle bearing from the OEM or aftermarket fails it can and will cause catastrophic engine failure where as the bronze bushing material will pass through the pump and be collected in the oil filter.
Our customers report that after the install of the bushing trunnion kit the LS valvetrain is the quietest it has ever been in his or her vehicle.
To date we have a little over 40K miles on 1 set of the bushing trunnions in a period of 16 months in a driving school corvette. I have several customers with over 10K miles on trunnion kits. I have airboat engine builder customer with over 300 hours on 4 LS3 engines with sustained 4400 rpm trips for 3 to 5 hours at a haul.
Again, the bushing trunnions will give out at some point, BUT when they start to fail they will tell you and warn you with increased valve train noise. When a needle bearing from the OEM or aftermarket fails it can and will cause catastrophic engine failure where as the bronze bushing material will pass through the pump and be collected in the oil filter.
Our customers report that after the install of the bushing trunnion kit the LS valvetrain is the quietest it has ever been in his or her vehicle.