| The Zinc Files – By Hap Waldrop |
| No matter which expert you talk to about our classic cars or what forum you visit, the reduction of the additive Zinc in our motor oils is a flaming hot topic. In the last few years, the government has required motor oil manufacturers to reduce or otherwise eliminate Zinc in or motor oils, so the old Castrol GTX for example you may have swore on for many years may not be the same oil it used to be. Through research, the government found that Zinc reduced the overall life of the catalytic converters in our modern cars.
Now in our classic cars most of them are cam in the block, solid tappet or lifter engines and Zinc helps condition the metal of the cam lobes and solid lifters and makes for longer life. There’s tons of information on the internet about this topic and many sites that discuss this into great detail, however you need to pay close attention to the date of the information, something written two years ago, or even as little as six months ago could no longer apply, as to recommended zinc enriched oils, as new government regulations are changing as we speak. All of this is enough to totally confuse any classic car owner. Now don’t worry. The oil companies and our government are not going to let us classic car owners destroy our engines. There are products and additives that are available for us to use. You are going to get plenty of suggestions from your fellow classic car owners as to what oil or additive they recommend. Some is good advice, and some, well not so much so. And the chances are that the kid at the counter of the parts store has no idea what you are talking about. So you may ask, what’s a classic car owner to do? Oil and oil additives containing Zinc have the ZDDP label on them, and already some oil companies have recognized our concerns and are making zinc enriched oil for are older engines, so quite simply look for the ZDDP label on the oil or additive you purchase, if your oil doesn’t have it, look for a brand that does. Ok you may ask, what do you use? I’ve long been a big fan of Valvoline oils, so in my 1967 MGB GT I use Valvoline 20W50 ZR1 racing oil which does have Zinc and has the ZDDP label on the bottle considered, also now Castrol is making their old high zinc oil and again, and is a good choice, it is labeled as Castrol GTX Classic 20/50. Ok, now I’ll reveal more about my theory about zinc in motor oil. I and many other engine builders feel the zinc enriched oil is a necessity for newly rebuilt engines for breaking in new cams and solid lifters. After break in, I suggest you continue to use these oils, and they are perfect oil for our solid tappet/lifter engines.1200+ ppm (particles per million) is the number we are looking for. There are even more choices now, Lucas, Gibbs, Penn, and others. The best advice I can give you from personal experience is to break in your new engine on a crude/fossil (non-synthetic) based oil that is zinc enriched or add a zinc additive to your oil for break in, remember to look for the ZDDP label. Then continue to use that oil after that at your regular oil change intervals. Happy motoring |
