happydude303

iTrader: (1)

im soon to be running in my new crank and bearings, ps the psitons and rings are the same as what was in it from 2 year ago they were all fine should i be ok with semi synt for 200 miles then changing to fully for rest and do i have to do i have to do the full 1000 miles job seen as the pistion are already run in

saiklon

Seems to me that running in is more of a personal preference and gut feeling than science so everyone seems to recommend something else. Based on what I know, plain bearings do not experience any metal to metal contact (unlike piston rings) so I don't really understand why they would need a run in period.

What I have had done on the last 2 engines that I had built was:
Crank engine to get oil pressure with the spark plugs out and cam sensor disconnected for the very first start up
Get engine up to temperature and change oil. This is to get rid of assembly lube and any dirt introduced during the build.
Drive 100km and change oil again. The idea behind this is to get rid of any remaining bits of dirt that might have remained in the oil from the first change.
Boost

I visually inspect the oil in the oil filter at each change for any metal particles. I get a few (about 5-10 very tiny flecks) the first oil change and none at the 2nd oil change.