Yeah, as far as I've read it's only a problem on older flat-tappet cams. They took zinc out of motor oil for a variety of reasons, but the most well known is that it started ruining catalytic converters. But with flat tappet lifters, there is a point where the edge of the lifter slightly cuts into the lobe of the cam during initial break-in. This was largely prevented by the older zinc oil, so to rebuild older engines, you use zinc additive. That's just how I read it anyways.
To re-iterate, I had more than a pint of Lucas Break in (which is their zinc additive) in with my 10W-30 pre-primed in the engine, and I only ran it for a few seconds at a higher RPM, with the valves already adjusted and the timing mostly set (still have to fine tune once it's running) Now that it is mounted on my frame, I'll be hooking up all the bells and whistles and I will run it for 20-30 minutes at an RPM varied between 2500-3000. That's just how I was taught to break-in an engine by my Grandpa and Dad.
Is that wrong? All those guys saying I ruined my cam by not following correct procedure have me worried now.
