Something not everybody knows yet,,, A while back they took all the sulphur and zinc out of motor oil.
Racers hit the first issues, You would build a sprint engine, run a couple sessions and the cam would go flat.
Without the sulfur and zinc it was not correctly hardening the surfaces of the lifters and the cam during the
break in run. One we started using the Additive or the special oil for new engines the problems went away.
Its especially critical with high lift cams and the accompanying heavy duty valve springs.
Dave