From Scott Wheaton who has done extensive research and testing on oil's and ZDDP levels for several years now.
Shell Rotella lowered ZDDP levels in 2007 from 1500 ppm to 1050-1100 ppm. Chevron Delo ZDDP levels dropped from 1500 to 1300 ppm, 1200 ppm is the minimum for use with stock to mild flat tappet cams.
Regular Mobil One does not have enough ZDDP, Mobile One High Performance synthetic also has 1300 ppm like Delo 15-40.
Also as I mentioned don't use any synthetic for cam breakin or any engine breakin, flat tappet or roller. I have a roller cam so ZDDP levels are not a big concern for me but I do throw in a few ounces of GM EOS at oil change.
I'll post up some more from Scott soon, after I get it together and let Scott have a look. He kindly offered to review it before I post it here.
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Hank
70 Chevelle SS396(454), M20, 3.73
My Chevelle
Last edited by Hank70SS; 01-08-2010 at 01:47 PM.
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