Originally Posted by wmjoe1953

Yup. The lifters gotta spin and the won't spin at a speed under about 1000. That spin is what polishes the cam lobes with out cutting a groove. It's not actually the lifters that are failing. what causes a flat cam at break in is the lack of spin, since the cam is rough when new, except roller cams. That roughness has to get polished by the lifter , and that happens with the spin. It doesn't take 20 minutes though, it only takes about 5-10.