1969cutlazz

Can anyone tell me how long and what RPM I should run my rebuilt engine for to properly break it in? Its a 1969 Oldsmobile 350. Everything is new. Built pretty much to stock. New cam,lifters,crank, etc. Thanks, Eric

joe_padavano

Rule of thumb is once you get it started and timing close, run the engine at 2000-2500 RPM for about 20 minutes to break in the cam. Then drive for the first 500 miles relatively normally, but try to avoid long term constant RPM cruising. You want to vary the speed, including coasting, to load both sides of the rings.

firefrost gold

make sure you put in break in oil. I used joe gibbs break in oil. It was more money but I had no problems. I think comp cams sells some too.

815Cutlass1972

If your close to Route 20 you should drive on it. It has different speed limits, hills, and down grades, so your not stuck at constant RPM. I just picked-up my car with freshly re-built engine from the Western Suburbs, and drove on Route 20 back home, which was about 50 miles. Now time to change the oil and filter. I used Brad Penn break-in oil, and will use Brad Penn 10W-30.

1969cutlazz

Good idea. I drive RT20 to work everyday.

Bayou Olds

Make sure you have some zinc in the oil, either through additive or through the formula of the company's mix.

1969cutlazz

Yes, I use Rotella oil cause diesel motor oil has better wear additives. I add ZDDP zinc additive to it as well.