Comp trunion upgrade failure (Check yours)
12-31-2012, 08:28 PM
#41
All 16 are worn on one side, bottom 1/3 only. Some are worn on both sides on the bottom 1/3.
S10, the trunion IS the inner race, as it is designed (nothing stock is reused). It's all one big kit. This stuff has 4000 miles on it in a new engine with all new parts.
S10, the trunion IS the inner race, as it is designed (nothing stock is reused). It's all one big kit. This stuff has 4000 miles on it in a new engine with all new parts.
12-31-2012, 09:33 PM
#44
Edit: Valve tips/rocker tips would show wear LONG before such a large area supported by a bearing if too much pressure were the case. They all look new.
Last edited by DietCoke; 12-31-2012 at 10:28 PM.
12-31-2012, 11:17 PM
#46
The motor has had 600 miles total of Joe Gibbs break-in (chg 100,600), and 3400 miles of VR1 synthetic (chg 3600) (10w-30). Top end is receiving plenty of oil, not sure how it could possibly be starving the bearings in that location. Open to ideas.
01-01-2013, 12:44 AM
#50
It's on the lighter side of springs that will support the lift and rpm. Step up the oil pump? It will make as much oil pressure and volume as I shim it to, same as ANY other ls pump with a 9/10 gerotor. Basically an LS6 pump in a different housing
Last edited by DietCoke; 01-01-2013 at 12:49 AM.
01-01-2013, 05:22 AM
#51
There are some inlet and pick up tube things that can pick up the volume.
Switching to a shaft rocker could have the same problem.
What are the rough specs on the cam. mine is 250 ish .650 reved to 7500 with the lunati spring kit and they have held up great
Tim
Switching to a shaft rocker could have the same problem.
What are the rough specs on the cam. mine is 250 ish .650 reved to 7500 with the lunati spring kit and they have held up great
Tim
01-01-2013, 11:25 AM
#52
The Valvoline vr1 synthetic is not the same as the conventional bud. I asked AES if I can switch and they said HELL no!
Like I've said I believe it's a combo of your lift and spring pressures. IMHO. I'm gonna open my **** up this week maybe today.
Like I've said I believe it's a combo of your lift and spring pressures. IMHO. I'm gonna open my **** up this week maybe today.
01-01-2013, 08:39 PM
#55
I'd be inclined to find another set of (well inspected) trunnions, redo them with your bearings and see what happens. In fact, those actually look like the machining process didn't make it through all the way, as in either voids or off-center machining. Doesn't even look like needle bearing damage...
01-01-2013, 08:47 PM
#56
I have seen it before on a set lack of oil caused it. had a pinched o ring never lost oil pressure just had a lifter tick. Ended up tearing up the trunions. Kind of suprised when I found what the problem was.
Trunions looked the same as the ones pictured
Trunions looked the same as the ones pictured
01-01-2013, 10:37 PM
#57
I believe that is within the realm of possibility, the trunions themselves possibly not getting oil, except
1: Some of them look fine on one side (why?)
2: The valve tips and rocker tips are pristine, as are the pushrod sockets (oil is making its way up there)
3: There is a shitload of oil getting to the top end of the engine. I don't see what would or could preclude specific trunion bearings from getting oiled. The parts are even completely saturated on removal. Obviously under load things are different, but datalogs show a strong steady 65--->80psi (bypass relief) from wot hit leading up to redline.
I even entertained the notion briefly that the vacuum pump could be causing odd oiling issues on the pull side (Pulls 13.5 inches at redline), but both heads show identical wear in the trunions, so that isnt that case (and of course, only some are worn).
1: Some of them look fine on one side (why?)
2: The valve tips and rocker tips are pristine, as are the pushrod sockets (oil is making its way up there)
3: There is a shitload of oil getting to the top end of the engine. I don't see what would or could preclude specific trunion bearings from getting oiled. The parts are even completely saturated on removal. Obviously under load things are different, but datalogs show a strong steady 65--->80psi (bypass relief) from wot hit leading up to redline.
I even entertained the notion briefly that the vacuum pump could be causing odd oiling issues on the pull side (Pulls 13.5 inches at redline), but both heads show identical wear in the trunions, so that isnt that case (and of course, only some are worn).
Last edited by DietCoke; 01-01-2013 at 10:48 PM.
01-01-2013, 10:57 PM
#58
You might want to check on the zzdp quantities, I used to sell the ZZdp brand.. went to an oil seminar and found different, now use the Gibbs...my .02
01-02-2013, 11:15 AM
#59
Trunion set on mine CompCam was heat treated - did a quick verification. I'd expect heat treatment had the correct RC hardness. However, I don't know what method CompCam used for hardening.
Your trunion surface hardness appears to have failed.
If heat treatment was not correct on yours, or it was case harden and it was done improperly, it could have that kind of damage.
The question is: If trunions were case harden, with case hardening often done in batches - how many are affected?
Your trunion surface hardness appears to have failed.
If heat treatment was not correct on yours, or it was case harden and it was done improperly, it could have that kind of damage.
The question is: If trunions were case harden, with case hardening often done in batches - how many are affected?
