Don't think you need a 3-bolt cam?

[f5journal]

I've been reading every one of these cam failure threads and I am getting antzy. Some say the new oils without something in it, some have pointed at Comp Cam cores made during a certain period, the 3-bolt thing..........what ever the deal is, we are not seeing LS3 engines last with cams put in them. It seem to be a real crap shoot. I think PQ's went the longest but still barely 50K miles or there about. Most are done by 20K

[strych9]

Something here is amiss. I suspect the cam gear pin sheared due to the valve-to-piston contact, and not the other way around. hard to say.

I'm not a believer it the, "blame Mobil 1" camp for cam failures. Far too many performance shops still use it with no problems. The failures are isolated; if it were the oil causing it, they would all fail.

Sorry OP, that's some nasty stuff to deal with, there. Best of luck to you.

[10aSSee D]

My new cam is a comp as well.

[SNSSTR]

Originally Posted by strych9

Something here is amiss. I suspect the cam gear pin sheared due to the valve-to-piston contact, and not the other way around. hard to say.

I'm not a believer it the, "blame Mobil 1" camp for cam failures. Far too many performance shops still use it with no problems. The failures are isolated; if it were the oil causing it, they would all fail.

Sorry OP, that's some nasty stuff to deal with, there. Best of luck to you.

I agree something does seem amiss just hard to pinpoint exactly what the cause of everything was...What started the downhill spiral??

Don't know if I will ever know for sure.

[Fast6.3]

Any failures with other cams. Lunati crower crane I no almost every company uses comp cores that is a shame tho

[PQ]

Originally Posted by strych9

Something here is amiss. I suspect the cam gear pin sheared due to the valve-to-piston contact, and not the other way around. hard to say.

I'm not a believer it the, "blame Mobil 1" camp for cam failures. Far too many performance shops still use it with no problems. The failures are isolated; if it were the oil causing it, they would all fail.

Sorry OP, that's some nasty stuff to deal with, there. Best of luck to you.

Agreed. This looks like the cam is a victim and not the cause. Rarely is it ever clear in the circle of death of scenarios.

Originally Posted by f5journal

I've been reading every one of these cam failure threads and I am getting antzy. Some say the new oils without something in it, some have pointed at Comp Cam cores made during a certain period, the 3-bolt thing..........what ever the deal is, we are not seeing LS3 engines last with cams put in them. It seem to be a real crap shoot. I think PQ's went the longest but still barely 50K miles or there about. Most are done by 20K

Yes mine went about 45 to 50k after the cam. Comp cam installed by Vengeance.

I should ad that the cam came out of another members car. It had been in his car for a few months.

This one is definitely a different cause. I could put new bearings in mine and a new cam and two new lifters and run it if I wanted. this one is FUBAR.

Originally Posted by Rohdeo16

Well, it's an LS3, cam was put in at 12,000 miles and car now has 20,000 miles. Cam is 6 months old. Comp Cam specs are 219/235 .607/.619 113LSA. Not sure what material it was made out of.

The guy tearing it apart also said there was some valve float. Apparently the Lunati springs didn't hold. Also had trunion upgrade installed at the time of cam install.

I carried my cam around the fest last year and asked everyone. Lingenfelter, JRE, and everyone. They pretty much all said the same thing. Either the wrong springs were used (which is not the case), they were installed improperly, or the cam just simply failed. Wasn't hardened enough.

I'd guess yours was not a cam at fault. Anything is possible here but it's more likely that you somehow jumped timing. Did the chain or sprocket show any damage?

Originally Posted by Bo White

Yep, the pin is only there for indexing purposes only. The big bolt and high torque value is what keeps the sprocket stationary. Early on some single bolts failed because the pin was too long and wasn't allowing the bolt a true torque.

I remember those. I agree too. They engineer those to work. While I still feel better with a 3 bolt cam on a high torque build I'd be ok with a one bolt stock cam.

[PQ]

Originally Posted by Rohdeo16

Don't know if I will ever know for sure.

Rarely do we ever know for sure on catastrophic failure.

I'm still down as well. I know how it feels. Sorry to hear about it. Hopefully you will be up soon.

[SNSSTR]

Originally Posted by PQ

I'd guess yours was not a cam at fault. Anything is possible here but it's more likely that you somehow jumped timing. Did the chain or sprocket show any damage?

There was no visible damage to the cam gear or chain. Chain is going to be reused actually.

[DKT]

Just by glancing, couldn't this happen by the cam bolt backing out.

[PQ]

Originally Posted by Rohdeo16

There was no visible damage to the cam gear or chain. Chain is going to be reused actually.

Ok. Then that narrows it significantly I think. The cam spun. I don't really see any other explanation.

It was idling when this happened? Damn.

Well, like I said, rarely is it ever definitive. I'd think it would happen on a hard decel but that looks spun on accel.

[SNSSTR]

I guess it's possible but it was a new bolt, torqued to spec, with loctite. And from what I see on the cam, the pin sheared but looks like the bolt held the gear pretty tight against the cam for a period of time until finally the timing got thrown out enough to f stuff up.

[PQ]

Originally Posted by Jered@DKT

Just by glancing, couldn't this happen by the cam bolt backing out.

Decel and then a quick accel?

I'd think they'd engineer these better. This is nothing to play with. So easy just to go 3 bolt in the first place.

[PQ]

Originally Posted by Rohdeo16

I guess it's possible but it was a new bolt, torqued to spec, with loctite. And from what I see on the cam, the pin sheared but looks like the bolt held the gear pretty tight against the cam for a period of time until finally the timing got thrown out enough to f stuff up.

But the car would have run like shit before it finally hit.

I'm guessing of course.

[strych9]

Well, the pin is simply there for initial alignment; it's the bolt's job to hold things tight enough to keep anything from slipping. Something would have had to seize suddenly to break the clamping force of the bolt enough to allow the pin to shear. Or, the bolt simply stretched or loosened for whatever reason. Still, only speculative.

I had my three-bolt up and running and, out of paranoia, rechecked a couple of specs. I found out that the torque I applied to the cam bolts was incorrect, because the spec I used was incorrect. I had to take the front cover off a second time to correct it.

There were a few swear words incorporated during that second endeavor.