Frod 21A vs 91

[KiWinUS]

I use 1600 grit wet & dry paper wrapped around stones on Sunnen pin hone with oil running. Finish looks almost like chrome.
Cheers
Tony

 

[JSeery]

...I've got a set of rods that were rebuilt years ago and the big end bore is finished in a fairly rough cross-hatch pattern. Rough enough that I've been afraid to use them in an engine...

Sounds like a typical finish for insert bearings. I would guess the machinist did not have experience with floating bearings.

 

[Hal Beatty]

Thanks guys, that's what I thought would be the case.
Guess that set of rods stays on the shelf... The machinist that did them was an old timer that was working in a "real" machine shop and should have known better. I think he disliked working on early flathead stuff and just wanted to get those rods done and out of his hair.