Forgive my ignorance, but is ZDDP AKA Zinc? I had heard more than a few engine builders suggest a straight weight 30, or a standard 10 w 30 that was high in zinc for break-in. I was told if I wanted to be really good, (read;anal), the best was to run 2-3 hours, change oil & filter, (to remove impurities during build and initial break-in), run about 10 hours, then change and run whatever high dollar synthetic oil I wanted.
I assume the high zinc content is for bearings?

How much hard earned cash did you just spend on your engines? How long do you want them to last before you dump more hard earned cash back into them? In between time, what are you going to demand of those engines? Why would anyone compromise a few bucks in the initial stages on anything less than the best oil you can get? Brad Penn is in my engines...first oil change will be at 3 hours. Then again at the end of the season...oil is something I wouldn't compromise on.

Taking a new engine to the dyno today. My machinist/dyno operator says that we will be using Amsoil 30W break in oil for initial startup. According to him, it will get the rings seated faster and new lifters love it.

Yes ZDDP is Zinc .Zinc dialkyldithiophosphate is the actual name but ZDDP is easier to spell.

Zinc is a multi functional additive, first it is a reserve boundary lubricant, when the oil film fail, it is zinc the helps keep the metal pieces apart.

Zinc is also an anti-oxidant which helps extend the drain interval of your engine.

Zinc is also a consumable, the numbers drop over time and this is just one of the reasons we change oil.

With the numbers (PPM) of zinc dropping in today's motor oils, coumpounder blenders are using zinc in combination with Moly.

Ken