Comp trunion upgrade failure (Check yours)
FormerVendor
Joined: Dec 2005
Posts: 250
Likes: 1
My guess would be material incompatability causing metal transfer under high pressure. Hardness alone isn't everything.
If it's case hardened 8620 instead of 52100 and the bearing is made of the higher grade 52100 it won't like running together under pressure. If you are running restricted pushrods you may want to change them as the additional oil flow would keep temperatures down. It would be interesting to see if anyone else is running the same brand/ batch without issues. I prefer the CHE upgrade with the bronze bushing and get rid of the needles.
Keep an eye on them after you get it back together, because if they are case hardened 8620 you will be in trouble if you break through the case hardening. A couple articles explaining the difference below.
http://www.astbearings.com/bearing-materials.html
http://www.bearings.machinedesign.co...emech6_36.aspx
If it's case hardened 8620 instead of 52100 and the bearing is made of the higher grade 52100 it won't like running together under pressure. If you are running restricted pushrods you may want to change them as the additional oil flow would keep temperatures down. It would be interesting to see if anyone else is running the same brand/ batch without issues. I prefer the CHE upgrade with the bronze bushing and get rid of the needles.
Keep an eye on them after you get it back together, because if they are case hardened 8620 you will be in trouble if you break through the case hardening. A couple articles explaining the difference below.
http://www.astbearings.com/bearing-materials.html
http://www.bearings.machinedesign.co...emech6_36.aspx
FormerVendor
Joined: Dec 2005
Posts: 250
Likes: 1
That's good not restricting the oil flow. I wonder if they can tell you if they have them running with higher spring pressures. I didn't know they had their own brand so it may be fairly new. You say 480# open, so I'm guessing around 200# seat pressure for hydraulics?
Thread Starter
10 Second Club
iTrader: (18)
Joined: Mar 2004
Posts: 3,869
Likes: 60
From: Richmond Hill, GA
Far less. These are the advertised specs. Mine all tested between 480-484 lbs at .670 which is right where they should be
Specs:
Install Height: 1.810"
Closed Spring Pressure: 148lbs @ 1.810"
Open Spring Pressure: 450 lb. @ .600" lift
Open Spring Pressure: 490 lb. @ .675" lift
Maximum Spring Lift: .675"
Coil Bind 1.060"
Spring Rate: 483lbs/in
I've posted this thread in three different forums, and each is going in its own direction. The internet is a great thing for gearheads. Lots of experience to go around.
Specs:
Install Height: 1.810"
Closed Spring Pressure: 148lbs @ 1.810"
Open Spring Pressure: 450 lb. @ .600" lift
Open Spring Pressure: 490 lb. @ .675" lift
Maximum Spring Lift: .675"
Coil Bind 1.060"
Spring Rate: 483lbs/in
I've posted this thread in three different forums, and each is going in its own direction. The internet is a great thing for gearheads. Lots of experience to go around.
Maybe now you can understand why I hesitate to bandwagon all the "latest greatest" parts. Its not great until proven great as far as im concerned and guinea pigging **** usually comes with some bumps in the road. Big cams are just plain pain.... Ask me about my solid Isky flat tappet BBC sometime uffff ( but man that thing was faaaaaasht hehe )
Anyways what you need to do is go Farmer style and make some plexi valve covers and put er all back together and wring the **** out of it on the dyno and shoot hi speed video through the plexi to see what the oil is doing. The stock caged bearings do not have oiling issues so compare and investigate the differences ( even small notches/grooves can be the difference from lube flow and no flow ). With those two steps you should be able to figure out if its lubricant related. Id also Rockwell test the trunion shafts and the bearing needles and speak with a die maker/engineer who knows bearing race specs for each to verify there isnt a manufacturer issue. It could also be a finish issue where the shaft "race" if you will is not the correct finish for the bearings in these things. That outta get you close to answers on why this happened
Isnt R&D fun?
Anyways what you need to do is go Farmer style and make some plexi valve covers and put er all back together and wring the **** out of it on the dyno and shoot hi speed video through the plexi to see what the oil is doing. The stock caged bearings do not have oiling issues so compare and investigate the differences ( even small notches/grooves can be the difference from lube flow and no flow ). With those two steps you should be able to figure out if its lubricant related. Id also Rockwell test the trunion shafts and the bearing needles and speak with a die maker/engineer who knows bearing race specs for each to verify there isnt a manufacturer issue. It could also be a finish issue where the shaft "race" if you will is not the correct finish for the bearings in these things. That outta get you close to answers on why this happened
Isnt R&D fun?
Thread Starter
10 Second Club
iTrader: (18)
Joined: Mar 2004
Posts: 3,869
Likes: 60
From: Richmond Hill, GA
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TECH Junkie
Joined: Dec 2005
Posts: 3,092
Likes: 11
Saw this from the linked thread. "FWIW Randy did mention these rockers should be broken in with a break in oil."
FormerVendor
Joined: Dec 2005
Posts: 250
Likes: 1
Honestly we have been using them exclusively when stock rockers are used for at least 2- 3 years on street and track cars and I would have to contact the customers to check on mileage, but rest assured if there was an issue we would have heard about it. If bushings last in rod pin ends, lifter bushings, valve guides , etc. then a rocker arm shouldn't be an issue.
Actually a roller bearing isn't an ideal design in an application where there is rapid direction changes and no full rotation. They are more suited to an application where there is full rotation and constant direction.
Look at what Isky and now Crower have done with the EZ- roll bushing in lifters. I just tore down for refresh an engine and planned to send them to Isky for a rebuild since they had been in over 4 seasons of drag racing with 400# seat and 900# open springs, but after clean-up they showed virtually no bearing wear. Needless to say, I'm sold. They did have some issues one time where they tried a different matl/ supplier and had to replace some lifters, but luckily I didn't get any of those. I only read about it from a few guys that had issues and they replaced them.
Actually a roller bearing isn't an ideal design in an application where there is rapid direction changes and no full rotation. They are more suited to an application where there is full rotation and constant direction.
Look at what Isky and now Crower have done with the EZ- roll bushing in lifters. I just tore down for refresh an engine and planned to send them to Isky for a rebuild since they had been in over 4 seasons of drag racing with 400# seat and 900# open springs, but after clean-up they showed virtually no bearing wear. Needless to say, I'm sold. They did have some issues one time where they tried a different matl/ supplier and had to replace some lifters, but luckily I didn't get any of those. I only read about it from a few guys that had issues and they replaced them.
Good to know! We use impregnated bushing in blower shafts for our industrial pneumatic systems. Got a call out of the blue about ten years back from an outfit that wasnt sure what they had and wondered if we could fix it. I go down there and take a look and yup its a spenser impeller system which we work on. This particular blower was installed in 1915 and had never needed a service once so no one at the factory knew who to call ( family owned place ). THe motor had packed it in so we swapped it and fired it up and the thing was still butter smooth on the same bushings to this day. THats incredible lifespan imo
Of course there was that damn furnace blower in my old place that ate shafts and bushings up but I digress maybe the service man *cough cough* had too many cold pops while working on it I dunno
Of course there was that damn furnace blower in my old place that ate shafts and bushings up but I digress maybe the service man *cough cough* had too many cold pops while working on it I dunno
TECH Junkie
Joined: Dec 2005
Posts: 3,092
Likes: 11
"They are more suited to an application where there is full rotation and constant direction."
That may be part of the problem. With the factory valve train system they were probably well within the design limits. However once you start adding spring pressure and lift things may go South in a hurry once you reach a certain point. If it was a pressure oiling system to the bearings maybe they would last longer.
That may be part of the problem. With the factory valve train system they were probably well within the design limits. However once you start adding spring pressure and lift things may go South in a hurry once you reach a certain point. If it was a pressure oiling system to the bearings maybe they would last longer.
If it is an oiling issue, then there should be local indications of overheated discoloration, sometimes accompanying with squealing noise, before seizing or catastrophic failure due to the binding condition caused by abnormal distortion.
OP was relatively fortunate.
OP was relatively fortunate.
On the left
5500 miles no problems had a oiling issue in 1500 miles did this.
on the right
after oiling problem was fixed 7000 miles they look like this.
Same eveything nothing was changed other than fixing the oiling issue. the oil issue was intermitent lifters would tic for 30 seconds then go away for 15 min. Took forever to figure out what it was.
The oil was 5-30 lucas with zddp added. Going gibbs this year after testing it in my car.
Tim
5500 miles no problems had a oiling issue in 1500 miles did this.
on the right
after oiling problem was fixed 7000 miles they look like this.
Same eveything nothing was changed other than fixing the oiling issue. the oil issue was intermitent lifters would tic for 30 seconds then go away for 15 min. Took forever to figure out what it was.
The oil was 5-30 lucas with zddp added. Going gibbs this year after testing it in my car.
Tim
DietCoke, look familiar?
Not so bad -
The worst one
Mine have about 8,000 miles on them, and were installed brand new with a brand new SLP ported oil pump at the same time.
So whats going on here ?
Here is a video of my car when I first cammed it, and I was concerned about the oil up top. I was told it was fine, maybe not :/
Not so bad -
The worst one
Mine have about 8,000 miles on them, and were installed brand new with a brand new SLP ported oil pump at the same time.
So whats going on here ?
Here is a video of my car when I first cammed it, and I was concerned about the oil up top. I was told it was fine, maybe not :/
Last edited by Cwarta; Jan 6, 2013 at 03:13 PM.