To me, the most important part is not the brand of oil. Any 'break-in' oil should have enough ZDDP to protect the cam and lifters. I think the problem comes when the engine is not set-up properly for an instant start or not pre-oiled. If the timing or fuel delivery isn't spot on, and the engine has to repeatedly be cranked without starting, there is a good chance that the damage may already be done. As has been said, the engine should immediately be run up to 2,000-2,500 rpm, the timing checked, and held there for 20-30 minutes. Of course, the cooling system has to be up to the job and a floor fan pointed into the radiator helps as well. Numerous articles have indicated that adding ZDDP on your own is probably not a good idea. I've broken in my last 2 engines, both with hydraulic flat tappet cams, with Comp Cams Break-in oil. After 200 miles I switched to Mobil 1 10-30w full synthetic, which I like because it keeps the inside of the engine so clean. The myth that synthetic oils cause leaks because they are more slippery was disproved long ago. JMO
