John, > I followed your postings on zinc and phosphoros additive for motor oil a > while back. I use the GM stuff myself. I am courious as to what years this > is necessary > to keep engine wear to a minimum. thru the 80's into the 90's? > thanks
Any year where the engine uses a cast iron billet camshaft and cast iron alloy lifters requires zinc and phosphorous for camshaft and lifter wear protection, including aftermarket cast iron billet performance cams. Any year where the engine is equipped with a hydraulic roller camshaft and hydraulic roller lifters doesn't matter, for ***all*** hydraulic roller camshafts are steel billet and the rollers on the hydraulic roller lifters are steel alloy compatible with the steel billet roller camshaft. Simply put, cast iron needs zinc and phosphorous and steel does not. But, zinc and phosphorous ***will*** promote improved ring to cylinder wall sealing in any engine, no matter what. Personally, I'd tell the EPA to go to Hell and use an oil that has healthy zinc and phosphorous additives in any engine, regardless. API SJ grade oils still have very healthy zinc and phosphorous content, while SL and SM grades had the content reduced greatly, respectively. SJ grade is listed for engines in 2001 and older. SL is for 2002 to 2004. SM is 2005 and later.That's the giveaway this issue is all about emission politics and not about science and engineering. So far, all the studies done to prove zinc and phosphorous will harm catalytic converters have been inconclusive. In a couple of engineering tests, there was evidence that zinc and phosphorous actually improved the catalytic converter efficiency. But the EPA wants those 2 additives gone, for it will mean older engines will eventually die, which is exactly what the EPA empire wants. Older engines and cars can't be banned by law, for the U.S. Constitution forbids it. The LBJ left liberals created the EPA to work on emotion, not science. No succeeding administration has been able to change it that much to require science, instead. A friend of mine works for the EPA. He has both a MS in mechanical engineering with honors and a MS in chemical engineering with honors. He'll state the above to anyone who will take the time to listen. My friend likes to tilt at windmills by working for the EPA to try to change it and give it some common sense. Milton Schick 1964 442 Cutlass [EMAIL PROTECTED]
