Cam Failure

[gradon]

I too had a feeling that the HV oil pump had a part in the failures--or at least it caught my attention. Unfortunately, it didn't stop me from buying one--I didn't want to pay $30 more more the stock one.

[oletshot]

I read about the HV pump causing cam failures. I understand the extra load it could put on the distributor gear, but I still don't see a lobe failure being caused by a HV pump. I don't see how they are connected. Anyway, I've read it enough to start worrying a little. I'm more worried about my lifters. They came with the clevite cam I bought. The cam was in a clevite box with clevite's name and part # printed on the box, but the lifters came in a small white cardboard box that had dividers to seperate the lifters but had no names or part #'s on it except for HT2011 hand written in marker. I'm wondering who and where these were made. They were supposed to clevite, but I'm not sure. To use some of the extra flow my HV pump will be pumping I put an oil squirter to the distributor gear (thanks John) and I will be pulling the lifters and grinding a flat on the side to provide extra oil to the cam right at the lobes (like crower camsaver lifters). Hopefully, this will drop the pressure to something close to stock. I also stayed with stock valve springs. Tirod if your care to explain how the HV pump causes lobe failures, I would be more than interested in your opinion.

[Flash]

I read about the HV pump causing cam failures. I understand the extra load it could put on the distributor gear, but I still don't see a lobe failure being caused by a HV pump. I don't see how they are connected. Anyway, I've read it enough to start worrying a little. I'm more worried about my lifters. They came with the clevite cam I bought. The cam was in a clevite box with clevite's name and part # printed on the box, but the lifters came in a small white cardboard box that had dividers to seperate the lifters but had no names or part #'s on it except for HT2011 hand written in marker. I'm wondering who and where these were made. They were supposed to clevite, but I'm not sure. To use some of the extra flow my HV pump will be pumping I put an oil squirter to the distributor gear (thanks John) and I will be pulling the lifters and grinding a flat on the side to provide extra oil to the cam right at the lobes (like crower camsaver lifters). Hopefully, this will drop the pressure to something close to stock. I also stayed with stock valve springs. Tirod if your care to explain how the HV pump causes lobe failures, I would be more than interested in your opinion.

I too believe that the HV pump is part of the cam lobe failures.............But i have NO CLUE why...............Can't even pull a good theory out of my butt on this one!!!!!!!!!

Does any one, have a reason Why, Theory or idea.........Like oletshot said, can see dist./cam gear ware.......not, lobe ware.


Flash

[gradon]

Instead of gear wear, is it the cam gear transmitting more heat due to additional pressure from the pump gear and to the adjacent lobes that is causing them to fail, or would the gear fail first?

[Flash]

Instead of gear wear, is it the cam gear transmitting more heat due to additional pressure from the pump gear and to the adjacent lobes that is causing them to fail, or would the gear fail first?

That's a good point, and my, be part of it.................All tho, not 100% of the time,........it seam like most of the time it's cylinder 5 or 6 that wipe a lobe out first............

Flash.

[1bolt]

So we know of a lot of camshaft failure scenarios - anyone have any stroker builds that have some miles on them, with no problems? If so what is the build (cam, oil pump type, piston/rod combo, valve spring combo, CR, quench, block/head work done, oil used or additive added, etc.), how many miles, how it was broken in, how the engine was used (light duty DD vs dedicated rock crawler vs high rev), etc. The more data the better. Maybe this will help eliminate some ??'s.

Well over 50k miles on mine, pretty close to 60k now. Melling HV oil pump, Clifford Cam, don't remember the lifter brand, probably crane "anti pump up", Mobil 1 since break in, 5W20 for the first 45 to 50k, M1 High Mileage (an SL rated oil with high ZDDP) then the last two changes or about 8k miles 10W40. Since I read so much weight of opinion on BITOG (bobistheoilguy.com) that our I6's show less iron wear with 40 wieghts...

By the way a bit off topic but since I started putting a spread sheet together with Oil additives levels and weights with coresponding wear metals based off of used oil analysis' from BITOG; I no longer believe there's significant reason to use the heavier 40 weights, the weight of opinion on BITOG seems to be good old fasioned popular opinion with nothing scientific to support it. But I'll know better when I finally correlate all the numbers.

Back on topic, my HV pump doesn't seem to have caused any problems. And I believe the ZDDP plus poorly made lifters is the culprit.

[Cheromaniac]

Instead of gear wear, is it the cam gear transmitting more heat due to additional pressure from the pump gear and to the adjacent lobes that is causing them to fail, or would the gear fail first?

That's a good point, and my, be part of it.................All tho, not 100% of the time,........it seam like most of the time it's cylinder 5 or 6 that wipe a lobe out first............

Flash.

Sure it was the no.6 in my case but any one of the other cylinders have been affected on other stroker cams over the years so I wouldn't attach any significance to that.
HV oil pumps can accelerate distributor gear wear if a heavy weight oil is used and the oil pressure is over 60psi. I have the Melling HV pump and I use 10W-40 SL-rated semi-synthetic. Oil pressure is 55-60psi cold, 50psi hot at 2000+rpm, 30psi hot at idle.