con rod bearing defect?

[steveo3002]

ive taken apart an engine with no known history

just out of intrest what would be the reason for the pit on one bearing ? others appear okay i think and no marks on the crank

 

[steveo3002]

bit closer

 

[Chris Stevens]

Looks like a defect in the bearing. The crank looks as though its quite badly marked though, so I would measure it for ovality and if ok get it polished before rebuilding with new bearings.

 

[doubleboost]

Defect in the bearing
Light polish & copper lead bearings

 

[steveo3002]

Defect in the bearing
Light polish & copper lead bearings

do you think it was fitted like that or the chunk has chipped away over the years?

 

[rikrobson]

I suspect it may have been fitted like that. any materiel that left the site of the defect would have left traces of its departure.

 

[steveo3002]

thats what i was thinking

the others look normal for a used engine right? no signs of abnormal wear and they still had some life left?

 

[rikrobson]

the others look fine. but since its appart theres no poiny in not doing it properly

 

[rtbcomp]

I've seen pits in white metal bearings that would have looked perfect when fitted.

That was most likely caused by a manufacturing fault, either the shell was not tinned properly or there was a high spot that overheated.

 

[brightspark]

the pit would have been there since manufacture as there's no damage or scoring to any other part of the bearing

 

[roofman]

to be honest i cant see it doing any harm iff left...it would just be an oil filled gallery anyway.

 

[gordon stephenson]

Probably faulty manufacture, but looks a bit like bearing fatigue but would not have expected to find it in that position.

 

[steveo3002]

thanks all , id never seen damage like that before

have replaced them all and its running now , just was an unknown "good runner bruv" type purchase , guessing it wasnt overly worn out by the bearings and no sludge or sparkly bits in the sump

 

[the snooper]

I would also say manufacturing defect, if it had started to seize there would be damage on both shells full length and deposits fused to the crank journal