Quote:
Originally Posted by JMatt
Camshaft manufacturers were the first ones to notice the adverse effect of API SM on the wear of their products...
|
My old IHC Scout engine uses flat tappets, and I became aware of the deficiencies of the newer standards via the Scout forum which I frequent. After rebuilding that engine, I was warned that many folks were wiping their cam lobes because the new oils did not contain enough zinc and phosphorus to provide proper tappet lubrication during the cams break-in period... a very critical time. (Most modern (newer) engines use roller valve tappets, which are not too much of a problem for the cam.) GM's E.O.S supplement was mentioned as a fix. My IH engine does not have a cat, so no worries there. I used it, all was well. Maybe I'll add a drop of E.O.S to my SRT until my supply of Mobil1 0W-40 is gone.
Here is an interesting article which ties in with what you mention about the Porsche engines:
Oils: What oil should I use? Which oil is best for my Porsche or aircooled engine?
-Steve