I have always loved to read any threads on oil for antiques on The Barn. Many have spoke many have differed. My policy has always been drive a little change a lot. I never let on to my wife what it costs to run my junk.
Lately I've gone on to Google to search the zinc question. What I found is that higher zinc levels rose during the fifties. Then, when Detroit began offering more power through radical valve lifts and compression in the sixties, a new level of zinc was being run to protect the accelerated cam ramp speed of muscle cars.
Naturally with -(as has been mentioned right here on The Barn)- catalytic converters, and the resort to factory roller cams. Zinc had to be reduced.
My readings of oil labs indicate that today's oils ( snowflake / star )have enough zinc to compare with pre and post war (that's us) oils. They are also blended with lube factors that were unheard of then.
My studies on The Barn find that the rebuilders, who have decades of experience keeping early V8s rolling, use valve spring pressures that are cam lobe friendly. -(unless you run a racer motor: Drags, Bonneville, etc high spring pressure is not desirable)
In conclusion I ask that it be considered that zinc is not oil. It is a form of
metal that was useful to prevent galling on our radical rides of yore. It kept a burnish on 'hot' high lift cams. The down side is that too much will actually break into the surface and create more wear.
Well, thanks for letting me ramble. (don't shoot the messenger) Thanks to The Barners that have educated me. Many names I could have, should have, would have, mentioned, (but my memory is becoming more far sighted) One that sticks, in my mind, the is the grin from 'Ol Ron 'Easy on the springs, the oils are good enough' or sumfin like dat
