Short cam life with new oils

we've used schaeffer oil in all of our farm equipment. its great stuff.

Also amsoil has a high zinc content oil as well, about $10/qt

http://www.amsoil.com/storefront/zrf.aspx

we run amsoil in our R6 for formula car. I'll vouch for amsoil as well, they're a great company and a first class product

While I am still skeptical the oil is your main culprit here is another brand of oil you may want to check out.

I've been using Brad Penn Racing oil, seen excellent results with it so far on the Engine Dyno and it has a increased ZDDP levels, cheaper then Royal Purple too...

www.penngrade1.com