zinc in oil?
From Comp Cams website:
Time marches on . . . and generally thats a good thing. But unfortunately, over time, some of the good stuff can get left behind. COMP Cams® Engine Break-In Oil Additive brings back the good stuff, delivering a specially engineered blend of extreme pressure break-in additives that have been removed from current off-the-shelf motor oils. Delivering added protection during the break-in process and beyond for all engine components, including the camshaft and lifters, COMP Cams® Engine Break-in Oil Additive is compatible with any petroleum, synthetic or blended motor oil.
COMP Cams® Engine Break-In Oil Additive extends the durability of internal engine components, protecting against premature camshaft, lifter and valve train failure. Best of all, COMP Cams® Engine Break-In Oil Additive has proven to deliver long term benefits with new or rebuilt engines through continued usage. Simply pour in a bottle for initial break-in, run the engine for approximately 1,000 miles, drain the system thoroughly and then refill with clean oil and another bottle of COMP Cams® Engine Break-In Oil Additive at each oil change
Ultimately, the zinc is a high pressure additive, that helps protect flat tappet lifters, especially during startup. The zinc is being removed, because it deteriorate (or coats, can't remember) the catalytic converter. OEM's have to warranty the converts almost forever (90,000 miles if I remember) so the OEM's are putting pressure on oil companies to reduce the stuff in oil that can kill converters. Most of the OEM are now roller lifters, or overhead camps, and do not need the protection of the zinc.
From Comp Cams website:
Time marches on . . . and generally thats a good thing. But unfortunately, over time, some of the good stuff can get left behind. COMP Cams® Engine Break-In Oil Additive brings back the good stuff, delivering a specially engineered blend of extreme pressure break-in additives that have been removed from current off-the-shelf motor oils. Delivering added protection during the break-in process and beyond for all engine components, including the camshaft and lifters, COMP Cams® Engine Break-in Oil Additive is compatible with any petroleum, synthetic or blended motor oil.
COMP Cams® Engine Break-In Oil Additive extends the durability of internal engine components, protecting against premature camshaft, lifter and valve train failure. Best of all, COMP Cams® Engine Break-In Oil Additive has proven to deliver long term benefits with new or rebuilt engines through continued usage. Simply pour in a bottle for initial break-in, run the engine for approximately 1,000 miles, drain the system thoroughly and then refill with clean oil and another bottle of COMP Cams® Engine Break-In Oil Additive at each oil change
Ultimately, the zinc is a high pressure additive, that helps protect flat tappet lifters, especially during startup. The zinc is being removed, because it deteriorate (or coats, can't remember) the catalytic converter. OEM's have to warranty the converts almost forever (90,000 miles if I remember) so the OEM's are putting pressure on oil companies to reduce the stuff in oil that can kill converters. Most of the OEM are now roller lifters, or overhead camps, and do not need the protection of the zinc.