GavinT Posted August 12, 2020 Report Share Posted August 12, 2020 Need a little help interpreting the wear on these bearing. The engine was ‘refreshed’ approximately 3000 miles ago. Crank ground to .010 under. The journals on the crank appear to be ok. Could this wear result from oil starvation at the initial start up after the refresh and/or dirt contamination trapped between the surfaces during reassembly?. Quote Link to comment Share on other sites More sharing options...
Erikl Posted August 13, 2020 Report Share Posted August 13, 2020 Interesting, as I think about it - I have never seen a bearing that was not either a.) Brand new, or b.) removed because of low oil pressure resulting in some kind of damage. Is it possible that is what a normal healthy bearing looks like with some miles on it? Did the motor have low oil pressure? Quote Link to comment Share on other sites More sharing options...
CarBuff Posted August 13, 2020 Report Share Posted August 13, 2020 Our engine's bearings looked MUCH better (smoother) than that with 76,000 miles on them. They had not worn down to copper. Looking closer, is it possible that @gtookeys 'wear' is just running-in? Quote Atwell Haines '88 Esprit Succasunna, NJ USA Link to comment Share on other sites More sharing options...
drdoom Posted August 13, 2020 Report Share Posted August 13, 2020 I'll wager that we are seeing the result of particle contamination here, fear it could be the dreaded glass bead treatment carelessly used by uninformed engine builders. Key tip-off is the circumferential grooving and lack of heat related discolouration. Gavin, you are fortunate in having pulled the thing before many miles of running as beads embedded usually score the journals over time. If I'm correct you should tear down completely, thoroughly clean all oil bearing passageways and reassemble with new bearings. The cam carriers must be carefully scraped clean on the journal surfaces in such cases to ensure no particles there. Any news on the thrust flange front? Quote Link to comment Share on other sites More sharing options...
Guest Posted August 14, 2020 Report Share Posted August 14, 2020 I believe this is damage from the dried crumbled sealant that was used to seal the oil pan to the MBP. There was a considerable amount of sludge in the pan that was non metallic and was gritty. When picking at the sealant residue on the flange it breaks away from the flange really easy and crumbles really easy. Steve, I decided to buy this ‘ recently ‘, miles wise anyway, refreshed engine instead of repairing the original damaged block and crank but unfortunately it appears I have caught a bit of a cold with it. As long as the block, MBP and crank are good I think I will be ok. Quote Link to comment Share on other sites More sharing options...
Chillidoggy Posted August 14, 2020 Report Share Posted August 14, 2020 Looks like you've found your smoking gun. 1 Quote Margate Exotics. Link to comment Share on other sites More sharing options...
drdoom Posted August 14, 2020 Report Share Posted August 14, 2020 Looks like you may well be ok with the new lump Gavin, good solution for the situation with any luck. Quote Link to comment Share on other sites More sharing options...
Guest Posted August 14, 2020 Report Share Posted August 14, 2020 I hope so. I was hoping to just get away with a belt service but alas not. Fingers crossed nothing horrible presents it’s self during the strip down and cleaning process. Quote Link to comment Share on other sites More sharing options...
snowrx Posted August 14, 2020 Report Share Posted August 14, 2020 This is why there's such forum emphasis on using the right sealants in the right amounts. My crankcase had even more crud when I opened it up the first time: Quote Link to comment Share on other sites More sharing options...
ragingfool35 Posted August 14, 2020 Report Share Posted August 14, 2020 wow. for future reference there is this http://www.darkside.ca/tech/CL77-3-402.pdf Quote chris90SEjust because I don't CARE doesn't mean I don't UNDERDSTAND Link to comment Share on other sites More sharing options...
Guest Posted August 15, 2020 Report Share Posted August 15, 2020 Damn...looks like sand. Is that blast beed matter? Quote Link to comment Share on other sites More sharing options...
snowrx Posted August 15, 2020 Report Share Posted August 15, 2020 In my case, it's a lot of fine bearing material, with excess hardened gasket scraps. 60K+ miles of unknown engine history, mains down to the copper. Quote Link to comment Share on other sites More sharing options...
Guest Posted August 16, 2020 Report Share Posted August 16, 2020 That is scary! Quote Link to comment Share on other sites More sharing options...
Guest Posted August 18, 2020 Report Share Posted August 18, 2020 MBP came off today and the mains have similar wear to the big ends. Big red flag when removing the oil draw tube....it came out way too easily. Further investigation revealed no olive. Unbelievable. 1 Quote Link to comment Share on other sites More sharing options...
drdoom Posted August 18, 2020 Report Share Posted August 18, 2020 14 hours ago, gtookey said: MBP came off today and the mains have similar wear to the big ends. Big red flag when removing the oil draw tube....it came out way too easily. Further investigation revealed no olive. Unbelievable. All too typical. Quote Link to comment Share on other sites More sharing options...
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