break-in oil?

I bet we have zillions of posts on this, lol. I made the mistake of breaking in a flat tappet engine with Valvoline VR1 but it wasn't the racing VR1. I lost a cam lobe and two days labor. Bad Idea.

Next time around I used Valvoline VR1 Racing oil and the Hughes additive from Hughes Engines and had no problem. Once it was broken in I used plain Valvoline with no detrimental effects.

Yes, the diesel oils are losing their zinc phospate and sulfur additives although the old stuff can be found here in there in stock.