i'm new to this forum and i don't claim to be an expert on oil changing and engine breaking in and i certainly didn't make this up about leaving oil in for the full breakin period! besides after further review this whole concept is a mute point! years ago when machining was in its infancy maybe this oil slurry concept maybe held more water than it does today. maching tolerences and techniques are far superior to yesterdays chiseling and grinding. parts made today are near perfect and the effect of what may or may not end up in the oil during the break in period , and the threads keep refering to "chips", it's more like extremely small particles; is on smoothing surfaces within the engine. yes, chips and chunks of metal will foul oil pumps etc. but we're not saying that! scre