Summit Racing oil

Rat Bastid said

Did that article say how much zinc was in that oil? I’ve seen pretty big losses of power with too much ZDDP but I’ve never seen any real damage from it. It had to be well over 2000 PPM I would guess. Of course, who knows how many PPM you end up with if you just dump an additive to the oil.

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Unfortunately not. Just that too much causes excessive consumption. I assume because they were using an additive rather than a proper oil ready to go.

How much is "too much" seems to depend on the oil. More detergent, and the oil can deal with more zddp since the detergent helps strip the excess. But the tipping point between good and excess does seem to be in that 2000ppm range. Actual damage seems like it would take time to occur. The zddp clogging up the hone finish in the bore leading to skirt and ring wear - but it's still a dry lube, so it's not like taking oil away.
Seems like it could lead to increased cylinder wall temps and loss of effective ring sealing could probably eventually cause problems from combustion gasses creeping by, but that's just a guess.