rod bearing = poop

jdub

Official SM Expert: Motor Oil, Lubricants & Fil
SM Expert
Feb 10, 2006
10,730
1
38
Valley of the Sun
If this crank has never been turned, the blue discoloration is from the factory induction hardening process used on the journals.

If you are correct about particles in the oil as the cause, it demonstrates why you want to use a good oil & air filter ;)
 

dan0311

New Member
Nov 28, 2008
15
0
0
broken arrow
did you check your clearances when you did the rebuild? i had rod knock and i got a new cranck with MATCHED rod and main bearings, not trying to undermine you by any means just asking. use plastigage, worked good for me. ALWAYS ALWAYS have the crank magnafluxed and polished at a machine shop when rod knock occurs, that way you can rest assure your crank has no cracks, and is in spec. also, if the machine shop turns or polishes the crank .005 (.010 overall diameter) it will take the coating of of it, so DONT go over about .003 of an inch.