Catasthrophic bearing failure

[AlphaVision]

I got rod bearing failure after the first 60 miles of driving. What frustrates me is how did it happen. I hope you guys can help me out finding the answer.

Rod Failure Images

I know I did wrong. I got carried away and boosted past 22 PSI before they broke. The upper rod bearings are smashed. The lower ones are good (in comparison). Crankshaft is lightly scratched. I drove her 4-5 miles to the garage after this happened.

You can see details for my build in my journal logs, but here is an outline:

- ACL Race bearings all the way.
- Manley rods with ARP bolts, torqued to 40 ft/lbs
- Balance shafts removed and rotated the bearings to tap the oil lines
- head oil port mod
- oil pressure was around 90 PSI in boost
- used 15w40 mineral oil

So please tell me what are your thoughts on this. I don't want to repeat this experience again.

 

[JacksonAuto]

What were your clearances? How do the mains look? If they're shot also I would suspect lack of oil. If the mains are okay then I would think you have a problem with your rod bearing clearances.

 

[AlphaVision]

The mains are ok. The rod bearings are the only one that have suffered damage. I don't know exact numbers. The only thing I remember is that the crankshaft didn't need a regrind.

UPDATE: The Oil Relief Valve was stuck at 1-2 mm open when removed the OFH. I guess it's to be blamed

 

[JacksonAuto]

I wouldn't blame the relief valve. If there was an oil supply problem there would be damage throughout the engine including the mains, cylinder head and bs bearings. You should find out what the rod bearing and side clearances were. Also check the big ends for concentricity.

 

[AlphaVision]

All right. I've learned my lesson. I will write the clearances down the next time.

How can I check the rod concentrity?

 

[ziggo0]

Looks like one of my motors when my oil filter backed off during a cruise.

 

[AlphaVision]

Well did you have any other damage than the bearings?

OK, found some tool to measure pistons "roundness"

Those are the pistons. I don't think they have seen any knock.

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[TSIfreek]

The pistons are fine. It all comes down to lack of oil to the rod bearings due to an oil supply fault threw the crank or rod bearing clearances to tight or the rod caps not being installed correctly. The mileage you put on the engine has nothing to do with the failure as to how much boost you were running you could have ran 0 boost and problem would have still happened.
Make sure next time the crank is cleaned inside and out as debis left inside the crank from a polishing will also cause this failure.

 

[AlphaVision]

All right. Thank you guys. Got a new crankshaft and will write down the clearances this time.