Thats a good artical you have there Tom, it explaines a lot.
But what it doesn't take into consideration is the new extreme ramp camshafts that have come out in the last 7 to ten years. These are the cams that need as much zinc as you can throw at them. Older stock engines, high performance OEM's excluded, need only standard motor oil meeting todays standards. Try that oil in a hopped up engine with a fast ramp cam, you won't get very far before the cam is smooth. Increase the valve spring pressure over a stock, and you get the same results, smooth cam!
Stock engines all ready broke in need only clean oil. But, if you are starting one with a new cam or fresh rebuild or cleaning, you better have some added zinc. At only $15 a bottle for Comp Cams additive, thats pretty cheap insurance.
I won't start a new engine unless it has cam grease, break-in oil, zinc additive, and been primed a few minutes before starting. Crane Cams and Comp Cams both have excellent information on break-in and oils on there web sites. I have
talked with guys at Butler custom cams, and they say you can flatten a cam in the first 30 seconds of start up if the engine is not prepped right. The first few rotations are the most important, so rotating the engine by hand can start the proccess if you are not carefull.
All the High Performance cam companys will tell you not to use synthetic oil for break in, for one its to thin, and two, it doesn't have enough additive. A few of them will void the warrenty if you synthetic oils! As soon as the engine fires, it should be turned up to 1800 to 2000 rpm, no messing about tuning, get the rpm up. The reason is splash oiling of the cam lobes, thats the only way it gets oil, and at idle its not enough for a new cam even with zinc added.
Joe
Last edited by Joe H; 11/01/2011 4:20 AM.
