Running in with todays pistons

[Ian Williams]

The important point as I see things is to avoid letting the engine idle for long periods when you fist start it in the mistaken belief this will help the initial bed in, the rings need to be loaded or the bores will very likely glaze, excessive revs early on will also cause this. After a rebuild I like the take the car for a short gentle run immediately after the initial fire up, I then dump the engine oil, this is an unfiltered system remember and no matter how careful you have been dirt from the rebuild and swarf from the initial fire up will be circulating. The engine is then driven reasonably normally avoiding high revs but not excessively nursing it either, a few hills are good they really help load the rings. I change the oil very regularly during the break in period to keep it clean, oil is far cheaper than all the money you have just lavished on a rebuild! Running in oil may be a good idea but I have never used it.