Question for Vern or SFDon about M30 break-in
Hi. I posted a question on the E28 board about the M30 engine and was told you were the guys to ask. I've just overhauled my '85 535i. I pulled the motor and did rings, bearings, valves, honed cylinders and cam. Everything was in good shape so kept old pistons. Did the first start up yesterday - started beautifully and ran well. So far have just let it idle for about 15 minutes, shut it off and did the final torque of the head while warm and drained the oil. I plan to do the first road test in a few days. I've read a lot of articles about engine break-in procedure and know about varying RPM, not lugging it, etc. I probably will tend to treat it on the gentle side - not a red-line shifter even when the engine is broken in. There is some thought that the break-in should be pretty aggressive and the revs taken up gradually and occasionally or else the rings won't seat properly. What are your opinions on this? Have I done the wrong thing already by letting it idle too much? Do you know how they break in the cars at the factory?