Rod bearings have you seen this?

[1KillerSS]

No everything looked spotless Pistons were clean and no cracked ringlands. Just two bearings on the back side of the engine.


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[BadAquaBluSS]

I'm by no means an expert, but I've talked to (Kevin) at AGP and he seems to think that I have bent connecting rods, I was using 15/40 Royal Purple when my engine damage occurred, my boost controller spiked at 22.5 psi on the stock motor. I'm thinking oil wasn't the issue. I went over to a friend of mine (Justin) Limitless Performance in Humble TX. So we can put it on the lift and listen to it, he gave me the bad news he thanks that the ticking noise I was getting is connecting rods, I'm thinking this is also where yours is coming from Kevin told me that the rods will kiss while rotating making the noise. I won't be able to tear my engine down until next month. I'm in the middle of buying a new house and don't want to have to move my car in pieces it's still drivable .

[UNRIVALED SS]

The miss you described is a good indicator.
This could have been a injector issue or a intake leak, either of which could cause a lean condition. remember those bearings are obviously beaten up on the power stroke side. So we know its some form of over pressure on the power stroke.
As for oil. I think your oil was ok but your your clearance was tight. Oil temps around 240-250 require the performance 20-50 stuff usually all things considered.

[1KillerSS]

It was well into operating temperature. Good information guys. Thank you for all your feedback.

Ordered everything but Pistons and rods today. I'll have them ordered tomorrow and will be On my way to a good reliable boost loving engine!


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[polizzio]

Many Pro Stock engines run synthetic 0-5W engine oil. NASCAR Cup engines use syn 10-30W, make 850 HP and operate under severe loads and temps for hours. I seriously doubt your usage of 20-50W syn oil contributed in any way to your premature or unusual bearing wear, but its way way overkill and unnecessary. Many hot rodders put in 20-50W thinking it has to be better, old school racing ideology.
Higher oil viscosity require more energy to pump/circulate than a lower viscosity. And today's full synthetics are superior lubricants.

Oil viscosity selection reading:

http://www.drivenracingoil.com/news/...des/viscosity/

[1KillerSS]

Originally Posted by UNRIVALED SS

The miss you described is a good indicator.
This could have been a injector issue or a intake leak, either of which could cause a lean condition. remember those bearings are obviously beaten up on the power stroke side. So we know its some form of over pressure on the power stroke.
As for oil. I think your oil was ok but your your clearance was tight. Oil temps around 240-250 require the performance 20-50 stuff usually all things considered.

Wouldn't there be evidence of a lean condition, when I took the engine apart? I know all it takes is a split second, if that, to create damage, but shouldn't there be something I can look at inside and say, "oh yea there it is"

I won't pretend to be knowledgeable about this, but anytime I have seen the internals of an engine. The "proof" of how it's tuned, or the health of the motor, has always been imprinted on the parts that you can't see when its all bolted together.

Once my engine was apart, the only physical evidence of anything that was undesirable, was a valve seal on cylinder number 5, and the two rod bearings on cylinder number 7 and 8 as shown and nothing else.

So I am asking, if I had experienced a lean condition strong enough to damage my bearings, wouldn't I see that footprint inside the cylinder? Should't there be something that we can all see and go, "hey that went lean"?

[JohnnyC]

There is no oil between the bearing and rod or cap. Usually out of round, lack of lube etc would cause wear on the face of the bearing where it would be running on the crank. The bearing still have the lock tabs on them by the look of it so it's not like they started spinning in the bore.

[polizzio]

Look at the common denominators in this, the rear cylinders only on each bank, and only damage to bearing on piston side of bearing. So I would say either mixture problems (lean condition detonation) or lubrication problems. LS engine lubrication is typically pretty solid by design, short of an oil pump failure.

Those two cylinders probably operate at the highest temps of the bunch, and your running pretty high boost. I'd tend to believe mild detonation in those rear cylinders under heavy loads/boost.......and time just took its toll. Maybe a fuel octane issue under high boost and the hottest operating cylinders = rod bearing damage on pressure side (piston).

Also another thought is your meth distribution per bank. Perhaps these two rear cylinders are getting inferior meth addition/distribution compared to the rest? Resulting in mild detonation/octane issues on these two cylinders only. Something is common only to the far rear cylinders....temp or mild detonation. And I'm strongly leaning towards the mild detonation issue under boost. What about codes? You didn't say anything about CEL or codes ever, yet you felt a mild miss.

Keep this in mind. You say tune is perfect but that data is collective per bank. The only way to really see what individual cylinders are doing is exhaust temperature recording/monitoring under high boost/severe loads. I would think it worthwhile after you have engine back together and properly broken in, to collect individual exhaust temps under load, on the chassis dyno with temporary exhaust probes on each header pipe. This data will really tell you what each individual cylinder is doing under heavy loads.
Or reading spark plugs after a dyno run. But reading plugs can be challenging. You have to make a hard pull, kill the engine, pull plugs and read em. EGTs tell all and easier.

[Unreal]

Are you sure that is even an issue? I find that staining hard to believe as far as making a knocking noise.

Check rods for straightness?

[polizzio]

Originally Posted by Unreal

Are you sure that is even an issue? I find that staining hard to believe as far as making a knocking noise.

Check rods for straightness?

Its not the staining on the rod shell OP's worried about. Its the wear/scoring in the bearing babbit.

[stevieturbo]

Originally Posted by polizzio

Its not the staining on the rod shell OP's worried about. Its the wear/scoring in the bearing babbit.

It is the marks on the rear side of the bearing and inside of rod he was concerned about.

I too find it hard to believe it has anything to do with any noises being made.

I've seen a hell of a lot worse run silently.

[polizzio]

Originally Posted by stevieturbo

It is the marks on the rear side of the bearing and inside of rod he was concerned about.

I too find it hard to believe it has anything to do with any noises being made.

I've seen a hell of a lot worse run silently.

And I agree with you....the bearing has not failed or spun, excessive bearing clearance. That would result in a knocking noise.
But his pics do exhibit some sort of an issue. a pounding force on the power stroke......mild detonation issues imo.

[1KillerSS]

Ill ask this one last time. wouldn't I see some sort of evidence with a lean condition. You can measure EGT's all day long, and read plugs. However I have done the next best, and the most extreme way of checking my tune, that is pulling my engine apart and looking at the pistons, and cylinder heads themselves, and they look perfect. If what you say was true then those cylinders would most certainly show it. I would tend to believe what Stevie and nick said, that I have a rod that is not quite straight somewhere.

Makes sense to me, I put the car into boost while it was down a cylinder and bent something. Next time im at t's garage ill look closer at the connecting rods. And to my knowledge ls3's have had plenty of failed oil pumps at least from what I have seen on C5. There were no codes to speak of.

[JohnnyC]

If there was a pounding force it would show on the face of the bearing as the pounding pushed the oil out. If the bore was out of round the bearing face would show abnormal wear patterns. Could be as simple as contamination between them on assembly, high heat, or even crankshaft end play.