ivai

I know that if you're doing the whole 9 yards and putting in new rings, main bearings and rod bearings, you start up the car, run it for about 10-15 minutes, turn it off and change oil.. then start up the car, run for ~1000 miles, then change oil.. or something along those lines.

I'm only planning on changing rod bearings (engine that gets 145-150psi compression numbers on all 4 cylinders when cold) what is my break-in procedure for them?

P.S. I'm changing the rod bearings because the engine has 130k miles on it and is out of the car.. Preventitive maintenance.

ivai

bump..

Daniel Dudley

Should be no break in, as I see it. Break in is more for rings, pistons, cams & lifters, possibly guides.

Good fitting bearings shouldn't wear in, they should just be in. Give it 500 miles, if you want to be cautious.

m42racer

Agreed. There is no no break in. As stated, if the clearances are checked and OK, you will be good to go. However, you may want to check after some running to see if the clearances you measured are indeed good by inspecting the bearings. Draining the Oil will show any bearing material that has been wiped off, but you may not see if any damage has been done from foreign objects travelling in the Oil. I know when engines are dyno'ed that the bearings are inspected afterwards to see if any damage has ocurred while been tested.

ivai

Thanks for the answers.