Comp Cams Trunion upgrade potential problem
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
If you install these using a hydraulic press there shouldn't be any issues. I bought an extra set of stock rockers and pressed the old ones out and pressed the upgraded trunions in and didn't have a single problem with any of them.
If you beat them in with a hammer and some sockets and find some of them binding afterwards it wouldn't surprise me. But even with a very slight bind I wouldn't worry too about it. If you come to a point where they are too stiff to move with your fingers something is wrong.
If you beat them in with a hammer and some sockets and find some of them binding afterwards it wouldn't surprise me. But even with a very slight bind I wouldn't worry too about it. If you come to a point where they are too stiff to move with your fingers something is wrong.
I did mine over a friends house with a manual ( crank style ) mini press took 4hs ( was BSin between sets ) all mine came out fine. Are you guys cleaning out the housing after you punch the originals out? I found the factory set I had had some small traces of dirt. Nothing that would scar the housing but I'm sure some motors will see more dirt / grit / shrapnel than others I also real lightly greased the housing( just enough to catch any leftover stuff* use gloves or old lent free thick rag i got pricked with a piece of shrapnel it was hell getting it out ) then installed them.
Failure for running brand new stock rockers over my old stock rockers? Dont think so.
Honestly, it sounds like a nice option, but I'd be pissed to see there is some 'fitment/clearance' issue. I prefer to leave this work to real machinist since I'm not. So the best option IMO, for the average DIY is to send rockers to Harland for an upgrade.
BTW, you seem to know your **** crainholio, but in the last replies I've read, you sound like a dick. Its not because you have more knowledge you can act like an ***. Should be the other way around. But hiding behind a keyboard is ok, its internet.
Honestly, it sounds like a nice option, but I'd be pissed to see there is some 'fitment/clearance' issue. I prefer to leave this work to real machinist since I'm not. So the best option IMO, for the average DIY is to send rockers to Harland for an upgrade.
BTW, you seem to know your **** crainholio, but in the last replies I've read, you sound like a dick. Its not because you have more knowledge you can act like an ***. Should be the other way around. But hiding behind a keyboard is ok, its internet.
I suppose Canadian superstition is a tad different than ours. Here, it's bad luck to make a statement such as you had made and I was making light of it. Oops.
Shouldn't be a problem any further, as...
Shouldn't be a problem any further, as...
This message is hidden because Johnnystock is on your ignore list.
Last edited by 01ssreda4; May 27, 2011 at 10:47 PM.
^
..More a language thing, since I write n speak french usually. I knew I missed something and might not be what I think..my bad.
Last edited by 01ssreda4; May 27, 2011 at 10:48 PM.
Today I tried my trunion upgrades in some brand new rockers and experienced the same problem.
I have taken measurements of my components and I am requesting blueprint specifications from Comp Cams. I am going to work with them to try to get to the bottom of this situation.
My trunions measure .6255"
My bearning outer shells measure .8145"
I have to find out from Comp Cams if these match their blueprint specifications and what they recommend for "crush" (interference fit) between the rocker bore and the bearing outer shells.
I have taken measurements of my components and I am requesting blueprint specifications from Comp Cams. I am going to work with them to try to get to the bottom of this situation.
My trunions measure .6255"
My bearning outer shells measure .8145"
I have to find out from Comp Cams if these match their blueprint specifications and what they recommend for "crush" (interference fit) between the rocker bore and the bearing outer shells.
something doesnt make sense here. I have installed this upgrade in well over 50 sets of rockers and never had one single issue.
after pressing out all the stock bearings and cleaning the rockers this was my procedure.
1. press in the bearing on one side of every rocker in the set.
2. turn the rocker over and set the trunion into the rocker and bearing
3. press in the bearing on the other side.
4. take a plastic handled screw driver and GENTLY tap one side of the trunion ONE time to create a very SLIGHT space between the bearings for the trunion to move freely.
end of story.
very simple upgrade. and again, I have NEVER experienced any issues with how the bearings fit into the rocker.
after pressing out all the stock bearings and cleaning the rockers this was my procedure.
1. press in the bearing on one side of every rocker in the set.
2. turn the rocker over and set the trunion into the rocker and bearing
3. press in the bearing on the other side.
4. take a plastic handled screw driver and GENTLY tap one side of the trunion ONE time to create a very SLIGHT space between the bearings for the trunion to move freely.
end of story.
very simple upgrade. and again, I have NEVER experienced any issues with how the bearings fit into the rocker.
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Brett Foote something doesnt make sense here. I have installed this upgrade in well over 50 sets of rockers and never had one single issue.
after pressing out all the stock bearings and cleaning the rockers this was my procedure.
1. press in the bearing on one side of every rocker in the set.
2. turn the rocker over and set the trunion into the rocker and bearing
3. press in the bearing on the other side.
4. take a plastic handled screw driver and GENTLY tap one side of the trunion ONE time to create a very SLIGHT space between the bearings for the trunion to move freely.
end of story.
very simple upgrade. and again, I have NEVER experienced any issues with how the bearings fit into the rocker.
after pressing out all the stock bearings and cleaning the rockers this was my procedure.
1. press in the bearing on one side of every rocker in the set.
2. turn the rocker over and set the trunion into the rocker and bearing
3. press in the bearing on the other side.
4. take a plastic handled screw driver and GENTLY tap one side of the trunion ONE time to create a very SLIGHT space between the bearings for the trunion to move freely.
end of story.
very simple upgrade. and again, I have NEVER experienced any issues with how the bearings fit into the rocker.
If you would, mic one of your trunions and tell me the diameter.
This would lead me to believe that the trunion itself must be out of spec. I have tried a complete second set of bearings from Comp and a couple brand new rockers with the exact same result. That means the only thing that remains the same is the trunion diameter.
If you would, mic one of your trunions and tell me the diameter.
If you would, mic one of your trunions and tell me the diameter.
I can make a phone call and get a measurement for you on tuesday.
I bought 4 more rockers and the same 2 trunion upgrades feel like **** in those 4. I have been waiting for about a month now for a couple replacement trunions from supplier but no luck yet, WTF!!!!
What are you using for rockers now?
I too have run into this issue. Two of the 16 have tight stops in their movement which seem to loosen themselves a bit and then bind again upon further turning of the trunion. Old bearings were carefully removed and new ones pressed in with a vise with aluminum protector plates against the rocker and bearings to prevent any damage. No issues or tight spots were observed during installation and every bearing / trunion assembly was checked for operation before installation in the rocker.
Once installed in the rocker arm, it seems the inner trunion is "screwing" between the two outer bearings when turned, being less tight when in between the bearings and stiffening once against either bearing.
Very interested as to what Comp has to say, as I am very concerned with runing my engine with these rockers in this state.
Once installed in the rocker arm, it seems the inner trunion is "screwing" between the two outer bearings when turned, being less tight when in between the bearings and stiffening once against either bearing.
Very interested as to what Comp has to say, as I am very concerned with runing my engine with these rockers in this state.
Launching!
Joined: Jan 2010
Posts: 283
Likes: 0
From: N. Va
speedtigger...keep up the efforts man...I appreciate your work. I did heads/cam swap not too long ago and purchased Comps trunion upgrade for added "insurance". I never got around to installing them and just stuck the stock rockers with needle bearings back in. So far so good...no noise and everything's working great. I planned on installing Comp's upgrade here soon...but after reading all of this I'm not sure I want to deal with the hastle!
I will. I could just drop the coin on some Yella Terra, but this deal has piqued my curiosity.
I am certain now that it is a production tolerance issue. I just don't know if it is a rocker bore tolerance variation problem or a trunion kit tolerance variation.
Some guys have all 16 that they say are silky smooth, while other guys say some are and some aren't. Like many guys, I used the same process for all 16 only a portion that were silky smooth. So, I ordered a compete set of bearings, disassembled, cleaned and re-installed the other with the utmost care and attention to detail. Exact same results.
My conclusion is that there is insufficient tolerance. I am waiting for a call back from Comp Cams now to collaborate on the trunion kit specs.
I am certain now that it is a production tolerance issue. I just don't know if it is a rocker bore tolerance variation problem or a trunion kit tolerance variation.
Some guys have all 16 that they say are silky smooth, while other guys say some are and some aren't. Like many guys, I used the same process for all 16 only a portion that were silky smooth. So, I ordered a compete set of bearings, disassembled, cleaned and re-installed the other with the utmost care and attention to detail. Exact same results.
My conclusion is that there is insufficient tolerance. I am waiting for a call back from Comp Cams now to collaborate on the trunion kit specs.
Teching In
Joined: Aug 2007
Posts: 2
Likes: 0
From: minnesota
I put a set in last week and when I got them all installed in the rockers I checked them and several were so rough they hardly moved. Everything was installed properly. They had spots that would catch if you hung onto the shaft and rotated the rocker.
I finally took them back apart and found that the machine work was so bad that there were flat spots all over some of the shafts. Some were so bad you could see the flat spots with your eyes.
I finally took them back apart and found that the machine work was so bad that there were flat spots all over some of the shafts. Some were so bad you could see the flat spots with your eyes.
I put a set in last week and when I got them all installed in the rockers I checked them and several were so rough they hardly moved. Everything was installed properly. They had spots that would catch if you hung onto the shaft and rotated the rocker.
I finally took them back apart and found that the machine work was so bad that there were flat spots all over some of the shafts. Some were so bad you could see the flat spots with your eyes.
I finally took them back apart and found that the machine work was so bad that there were flat spots all over some of the shafts. Some were so bad you could see the flat spots with your eyes.
Comp Cams did not call me back with the specs, but when talking to the tech on the phone, he said the interference fit should be .002". That seemed like a lot to me. Since Comp did not call me back and they had closed for the day, I called the guys at Crower (they are out west and were still open). I asked them how much interference fit Crower runs on their roller rockers bearing shell. He said we run .001" on our steel rockers but a lot of the aluminum rockers run .002" interference fit to compensate for the expansion of the aluminum. This could possibly be causing the problem. Too much interference fit could be not only causing too little tolerance, but it might also cause the bearing shell to distort. To state the obvious, if the bearing shell is not perfectly round, that is a problem.
I am looking forward to getting these specs from Comp to confirm.
The phone call with Comp Cams today was bizarre. First, I have to say that after talking to two people yesterday, nobody called me back. When I called back today, I was told: "nobody called me back because they don't have any in rockers in stock to measure". I am not sure how being out of stock affected their phones, but that was the answer.
Once we established that they are "out of stock", I asked: "can't you just check the engineering specs?" to which he replied: "I don't know if we have anything like that". That one stunned me. I responded: "how can that be?" to which he said "I don't know if we have anything like that, but I will ask around and we will call you back".
We shall see if they call me back and what they say when they do.
Once we established that they are "out of stock", I asked: "can't you just check the engineering specs?" to which he replied: "I don't know if we have anything like that". That one stunned me. I responded: "how can that be?" to which he said "I don't know if we have anything like that, but I will ask around and we will call you back".
We shall see if they call me back and what they say when they do.