31-08-2012, 07:13 AM
Big end bearings aren't really something that need "running in" - they're essentially only for cold starts, once the engine is up to temperature and the oil is doing it's job properly, you're running on a film of oil, if you've got metal>metal contact, that bearing surface will be knackered in seconds! IMHO just change the oil a bit sooner - say run it for 500 miles, then just go straight for the good oil... Piston rings fair enough, they do take a good amount of bedding in, you get a good amount of leakage past the rings for the first few miles which does in the oil... But big end bearings shouldn't need it at all.
