Oil Starvation? Or Foreign debris? What do you guys think

 

I'll take foreign material for $500, Alex.

 

I would say low oil pressure if it was foreign material you would see the marks of the foreign material going all the way around the bearing . what does the crank and rod bearings look like and did it ever lose a head gasket ?

 

I'm with 4wd on this one. Oil was contaminated with something bad.

 

Lack of lubrication!

 

looks like grit/fine metal particles in the oil. You dont by chance run the fram "orange can of death" do you?

 

Some of the marks may be from disassembly but I will guess that excessive wear resulted in excessive bearing to shaft clearances that allowed wear debris or other contamination to get between the bearing surfaces where there should only be oil film. Things avalanche from there as more wear debris is generated. May be the photos but it seems there is a fair amount of varnish build up. I will assume this is a high mileage engine that has not always been well maintained or had other issues such as antifreeze in the oil.