Finally pulling the trigger on parts!
Thread Starter
Joined: Aug 2004
Posts: 11,258
Likes: 146
From: Pace, FL
Yella Terra. They haven't published it. However, when you search the forums, you'll see folks who have called and been given various numbers for the spring pressure. It's somewhere in the 420# open range.
All rockers are designed to work to a certain point before failure.
Here's one I found in a quick search: http://www.ls1gto.com/forums/showthread.php?t=438956
All rockers are designed to work to a certain point before failure.
Here's one I found in a quick search: http://www.ls1gto.com/forums/showthread.php?t=438956
Yella Terra. They haven't published it. However, when you search the forums, you'll see folks who have called and been given various numbers for the spring pressure. It's somewhere in the 420# open range.
All rockers are designed to work to a certain point before failure.
Here's one I found in a quick search: http://www.ls1gto.com/forums/showthread.php?t=438956
All rockers are designed to work to a certain point before failure.
Here's one I found in a quick search: http://www.ls1gto.com/forums/showthread.php?t=438956
Thread Starter
Joined: Aug 2004
Posts: 11,258
Likes: 146
From: Pace, FL
Jake, FYI: Per Tony Mamo, Gen III 6645 YT's are designed to withstand operation with 500# open spring pressures. I also emailed YT tech so we'll see if we get congruence. Makes me feel a little more confident as I'll be running them in my heads set up with 420# springs and a moderate cam (tick street heat stage 2). Guess we'll see how they do.
Thread Starter
Joined: Aug 2004
Posts: 11,258
Likes: 146
From: Pace, FL
Hmm. Was thinking about this as well before I pull the trigger on the transmission and converter...
RPM Level V 4L60E + FTI 3800 = 3144
Jake's Level 2 4L80E + FTI 3800 = 3029+core
Something tells me a built 4L80E would be much more reliable...
RPM Level V 4L60E + FTI 3800 = 3144
Jake's Level 2 4L80E + FTI 3800 = 3029+core
Something tells me a built 4L80E would be much more reliable...
Last edited by JakeFusion; Apr 4, 2013 at 01:10 PM.
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Teching In
Joined: Apr 2011
Posts: 43
Likes: 0
From: League City, Texas
Really nice build, sounds like you and I think exactly the same when building motors, spend a little more now for the peace of mind later. My build(about to go in the car, cant wait) is very very simular to yours only in a 408 with an ls3 style top end.
I will look forward in seeing how your build goes keep us posted.
I will look forward in seeing how your build goes keep us posted.
Last edited by mr slow; Apr 5, 2013 at 10:24 PM.
Thread Starter
Joined: Aug 2004
Posts: 11,258
Likes: 146
From: Pace, FL
So, instead of buying the Comp Trunion upgrade and hoping for the best with that, I've been kicking around the idea of the YT 6645 Ultralites.
I believe the factory rocker is great for my needs and will work well, but my setup wouldn't be too much for the YTs. 400lbs open pressure, endurance lobes, and lightweight valves. Just wondering if doing a roller rocker, even if it is a little bit heavier, would be beneficial to me. Obviously the geometry over .550" lift, wipe pattern, and side loading are all negatives against the stock rockers, but with PM guides, I don't see any of them being huge problems. The biggest negative is even with the upgraded trunions, they aren't bulletproof.
This leads me to the CHE Upgrade, which is $510 outright installed in core rockers or $640 in new GM rockers. This is far more expensive than the YTs. It makes the stock GM rockers pretty much bullet proof for my setup. But it doesn't alleviate any of the issues with the stock rockers.
The YT have caged bearings that are massive, are fairly lightweight (not as light as OEM tho), and can be setup for better wipe/geometry/full roller action for less friction. Their negative is they break, but I think that goes to the whole valvetrain is improperly setup. Plus that's supposedly fixed.
Any suggestions? Btw, if I do the Comp Trunion, I may end up buying a whole new set depending on how the tips look. So price wise, the YTs aren't much more expensive and are cheaper than the CHE upgraded OEM Rockers.
I believe the factory rocker is great for my needs and will work well, but my setup wouldn't be too much for the YTs. 400lbs open pressure, endurance lobes, and lightweight valves. Just wondering if doing a roller rocker, even if it is a little bit heavier, would be beneficial to me. Obviously the geometry over .550" lift, wipe pattern, and side loading are all negatives against the stock rockers, but with PM guides, I don't see any of them being huge problems. The biggest negative is even with the upgraded trunions, they aren't bulletproof.
This leads me to the CHE Upgrade, which is $510 outright installed in core rockers or $640 in new GM rockers. This is far more expensive than the YTs. It makes the stock GM rockers pretty much bullet proof for my setup. But it doesn't alleviate any of the issues with the stock rockers.
The YT have caged bearings that are massive, are fairly lightweight (not as light as OEM tho), and can be setup for better wipe/geometry/full roller action for less friction. Their negative is they break, but I think that goes to the whole valvetrain is improperly setup. Plus that's supposedly fixed.
Any suggestions? Btw, if I do the Comp Trunion, I may end up buying a whole new set depending on how the tips look. So price wise, the YTs aren't much more expensive and are cheaper than the CHE upgraded OEM Rockers.
The problem with making this decision (as you know) is that there isn't any one option that has no downside.
The comp trunions work for a lot of people, but all they fix are the bearings. Meh.
CHE's, same thing except 3x as expensive as the comps. Meh x3.
The YT's address the additional issues, but have a spotty past. But given their redesign, the fact that they're backed by a lifetime warranty against manufacturer defect / failure, and that they address sideloading, reduce valvetrain friction (free power), improve wiper pattern at lifts > 0.550"... they seem to be the winner of the 3 choices (for me at least).
As you alluded to though, the entire setup is critical...there is no magic lifter or magic rocker arm or magic springs that will do the job all on their own. Everything needs to work together.
The comp trunions work for a lot of people, but all they fix are the bearings. Meh.
CHE's, same thing except 3x as expensive as the comps. Meh x3.
The YT's address the additional issues, but have a spotty past. But given their redesign, the fact that they're backed by a lifetime warranty against manufacturer defect / failure, and that they address sideloading, reduce valvetrain friction (free power), improve wiper pattern at lifts > 0.550"... they seem to be the winner of the 3 choices (for me at least).
As you alluded to though, the entire setup is critical...there is no magic lifter or magic rocker arm or magic springs that will do the job all on their own. Everything needs to work together.
Go with stock steel rockers, I think you'll be fine with you combo..
Lunati offers new gm rockers with their own trunion upgrade pre-installed for about $270..
http://www.coloradospeed.com/lunati-...-pr-20404.html
Lunati offers new gm rockers with their own trunion upgrade pre-installed for about $270..
http://www.coloradospeed.com/lunati-...-pr-20404.html
Thread Starter
Joined: Aug 2004
Posts: 11,258
Likes: 146
From: Pace, FL
That's interesting on the Lunati. Seems everyone has their own version of the caged bearing now. Summit. TEA.
I'm guessing they are all sourcing from the same Chinese company and putting their name on it?
And yeah, the whole combo is critical. I might just pull the trigger on the YTs. The claim is they free up 7-9HP because of the friction loss (assuming you can control the added weight).
I'm guessing they are all sourcing from the same Chinese company and putting their name on it?
And yeah, the whole combo is critical. I might just pull the trigger on the YTs. The claim is they free up 7-9HP because of the friction loss (assuming you can control the added weight).
That's interesting on the Lunati. Seems everyone has their own version of the caged bearing now. Summit. TEA.
I'm guessing they are all sourcing from the same Chinese company and putting their name on it?
And yeah, the whole combo is critical. I might just pull the trigger on the YTs. The claim is they free up 7-9HP because of the friction loss (assuming you can control the added weight).
I'm guessing they are all sourcing from the same Chinese company and putting their name on it?
And yeah, the whole combo is critical. I might just pull the trigger on the YTs. The claim is they free up 7-9HP because of the friction loss (assuming you can control the added weight).
I think summit also makes some trunion upgrade made in the U.S and the clips look alot "beefier" then the comp trunion kit
Edit: here
http://www.summitracing.com/parts/sme-143002
Edit: here
http://www.summitracing.com/parts/sme-143002
Last edited by adamantium; Apr 7, 2013 at 12:42 AM.
FWIW I've never seen a stock rocker body break. I have 4 customers running in the 5.0-5.50 range in the 1/8th mile with hydraulic roller cams, BTR Platinum springs, Tool Steel Retainers and stock trunion upgraded rockers.
No need for roller rockers IMO unless you're going mechanical roller and/or cannot have your heads done with steel(powdered metal) guides.
No need for roller rockers IMO unless you're going mechanical roller and/or cannot have your heads done with steel(powdered metal) guides.