I will agree, that most people will never have a problem with oil during a break in. Once the new engine is broke in, it really doesn't matter what oil you use.
The main concern these days is the camshaft. Most new cams (Comp Cams for sure) use a much more radical lobe then they did only 10 years ago. They like to slam the vavle open as soon as possible, then drop it shut. You can get a lot of duration with out a lot of over lap doing it this way. The older cams have a much longer ramp on them which produces less stress and wear. Just look at the lift at .050" to .100" and you will see what they are doing. A stock camshaft will be just fine with stock valve springs. Its the radical race cams with high pressure springs that coming apart.
Our engine was a high performance street engine make around 500hp. We used the best products we could and yes, it had a radical cam lobe. Once the hard surface wears, even just a bit, it will eat the cam in just a few miles. The zinc protects and coats just as the lead in fuel did for valve seats.
On the Comp Cams web site, they now recommend Brad Penn Racing oil for all of there cams. Brad Penn is the old green Kendal oil from the 70's. Its still a high Zinc oil, just a Rottella is.
Joe
