First, let me state I am 100% in favor of leaving zinc in oil and am a believer in it's load bearing properties. Also, I too deplore government's utter disregard for our wants and needs. However, let's be a bit realistic here. Not having zinc is not going to destroy your older engine. Think about it. What is the hp/ci of a 235 compared to just about any newer car? Much lower. How about the rpm range? Again, much lower. How about the bearing journal size? Aah, much wider and much larger in diameter. Now, I admit that there are only 4 main bearings, and larger diameter journals equates to faster bearing speeds, but this is on an engine in which "high rpm" means 5000. My dd 85 celica's redline is 6800, and that's an "old" car. I submit to you that the oil wedge size and bearing loads are much more conservative than in a new honda 4 cylinder, which will easily run for 400,000 miles with zinc-free oil. The real killer of old engines is oil contamination. Use a real oil filter (that's not painted orange), change your oil frequently, and get the carb/ignition systems operating optimally! Most old cars are quite rich, because rich is easy to start, easy to keep running, and easy to ignore. Get your mixtures correct, your oil will stop breaking down. Make sure your crankcase evac system is working properly to help pull out the contaminants that are volatile. They said taking the lead out of gas was going to kill our engines in the 80's, and I put another 100,000 miles on the 265 in my bone stock original 56 belair since then. It still runs and drives well with 240,000 on it, although it's starting to use oil. 23 mpg on the interstate. No zinc additives, no fancy oils, and once my mom went 10000 miles without changing the oil and it came out looking chunky like rotten milk.
