NEstyle

iTrader: (1)

Maybe because barely anyone ever actually takes them apart after running them? Not saying, just speculating.

Johnny_M

that is true. They won't make noise. Most don't cut their oil filter open when they change oil either. I seen the bronze glitter in the filter when I cut the filter open on an oil change.

Johnny_M

I talked to Kenny Duttweiller. ( for those who know, know)
I told him that the bronze trunnions wiped out and I have galling on the tips of my intake valve stems.
He got into details about the LS rockers and in a nutshell he said stock rockers with or without the trunnion upgrade will bind up with any cam over .600 lift.
That explains the trunnion failure....
He said any roller tip rocker will cure this issue. He suggested the Comp ultra pro magnum for my ls3 application. You can't beat the price on them.

Bspeck82

hard to argue with kenny
But with regards to rollers, imo I'd run the tsp steel bodied rockers. Less fatigue and lighter weight.

Urocmyiroc

I have the Straub kit, still in the package. it was going to go into my LS1 with TSP 2.5 243 heads milled 25 thousands and the bald eagles cam...
.600 / .600... are you guys saying that is a bad idea?

Johnny_M

After talking to Geoff Skinner and Kenny Duttweiller. Geoff is not a fan of bronze trunnions. Kenny said keep the lift below .600 for stock rockers. You can decide from there....

Urocmyiroc

Thanks, you may have just saved me some headache. And to think I just stumbled across this thread.

I just watched a 3 week old video on YT showing the bronze wearing.


I got talked into the bronze trunnions and already knew that bronze was too soft.

moving on... any issues with the TSP 1.72 rollers? Or are they good to go?

Johnny_M

I talked to TSP. They have been using them on their Test car for 2 years at 8500 rpm with no signs of wear. I believe they are holding the N.A. record with stock bottom end with that car but don't hold me to that...

wannafbody

iTrader: (2)

Brian Tooley seems to have indicated that .630 was the danger zone for stock rockers.

Johnny_M

I'm running a .624 lift cam on the intake and I have galling on the intake stems. .609 lift on the exhaust and no galling on the valve stems. All the bronze trunnions failed on the intake and exhaust rockers. The roller tip rockers have come down in price to the point that it's not worth the trunnion upgrade for stock rockers. The roller tip solves the scrubbing and locking up issue with the stock rockers above .600 lift

NEstyle

iTrader: (1)

Are you saying that with roller tip rockers you're going to run factory needle bearing fulcrums? Why would you want to do that? Or are you saying that a roller tip rocker will come with a bronze fulcrum? If that's the case, you still have no idea that the roller tip is going to prevent fulcrum wear.

Urocmyiroc

From my understanding, the TSP rockers have a upgraded trunnion that is encased steel with needle bearings that prevents them from coming out like that of the OEM bearings. The roller end, albeit adding about 3 grams of weight, prevent the pad of the rocker from galling the valve tip due to high cam lift. Even though I have read that .600 doesn’t exactly reach that galling threshold, I’m changing it as some added insurance since I have to get new pushrods anyway. Correct me if I’m wrong...

NEstyle

iTrader: (1)

I don't know... Straub has been saying for years that the bronze trunions will wear. There's a ton of pressure on that soft metal, the valves open and close 30+ times per second, and they are NOT oiled! How would they not wear? I'm not sure it has anything to do with lift. I just think guys are finally taking them apart after getting some miles on them and they're finding wear.

Johnny_M

I never said to run factory fulcrums. roller tip rockers don't come oem needle bearing trunions.
they come with the brands trunnions installed.
the roller tip helps to take load pressure off of the fulcrum.
will it stop bronze trunnion wear? I don't think it will. The bronze is a wear item, but so are roller bearing trunions. Which one lasts longer? My guess would be the bearing type.

00pooterSS

iTrader: (40)

Lol I don't know how you got any of that from what he said man.

I don't know how to translate what he said any other way than how he said it or I would give it a shot.

Johnny_M

higher pressure springs causes galling too.
as for the threshold for oem rockers. My guess is the environment they are run in. Some say .630 lift is max others .600
I'm going 7k at the dragstrip. I definitely have the results with .624 lift being over the threshold.

00pooterSS

iTrader: (40)

I've always heard it was right around 620 that the problems start

So I always figured why not just stick with 600 lift where you can, prefer to recommend ~ 610 max myself, or go roller tip.

Urocmyiroc

Makes sense, I got dual valve springs so the more reason I took your good advice and already bought the TSP 1.72 steel roller rockers.

NEstyle

iTrader: (1)

Thanks for clarifying, Urocmyiroc and Johnny_M.

00pooterSS

iTrader: (40)

See if that helps

The stock rocker can only go down so far before it starts to pull back across the tip of the valve. Picture the rocker arm going up and down in a small amount then picture it going much further. At a certain lift point the tip of the rocker starts to rotate down and back towards toward the pushrod/mounting bolt of the rocker and if rolls over the nose of the rocker and off of the smooth pad made onto it which does several bad things. It pulls back/across the tip of the valve pulling on the valve and affects valve and guide wear, it also wears the metal on the tip of the valve. Roller tip rockers solve this problem and also provide a more consistent lift at the valve throughout the rocker sweep. The OE rocker actually loses a bit of lift at the valve as is rolls over the nose.