Big end wear, what's your opinion?

[Deleted User 62]

Pulling apart a longblock that had a rod knock, and I got as far as the offending big end. I am really no expert at diagnosing these things so tell me what you think about these bearing surfaces:

[Ross]

Silly BM question. How many suspected kms on the crank???

[Major Softie]

Well, you certainly have significant wear on the bearing shell, but your crank journal looks great. I would be tempted to just have it measured and buy the appropriate new bearing. Some think you always have to polish.

[Deleted User 62]

No idea on the mileage. Bought from kpmccord who used to post here. He said he built it from parts. This is the same engine with the R90S cylinders. Are there different big end bearing sizes? I thought it was one size fits all. And yes, it's the polishing I'm wondering about... I really would rather not tear the bottom end apart if I can avoid it.

[ME 109]

Pollish with a flat shoe lace with.............I forget the pollish name. I don't think it's from Poland.

Those shells have wear, but not excessive.
Might be difficult to measure accurately with the crank in the block, maybe just start with standard shells and use plastigauge to be sure..

Pollish as the major says, but only after flossing.

[Deleted User 62]

A shoe lace and jewelers rouge, perhaps?

[ME 109]

A shoe lace and jewelers rouge, perhaps?

Where's GSPD when ya need him!

[Bob Bennett]

I think it was "AUTOSOL" metal polish that GSPD used. (with the bootlace)

[Major Softie]

I think it was "AUTOSOL" metal polish that GSPD used. (with the bootlace)

Simichrome would be an equivalent.

[dougie]

Autosol, Simichrome, or Mother's Billet. All good.