[Richard]

I was watching a program that concerned building high performance race engines. Part of the program showed them trying different tricks on the same engine, and putting the engine on the dyno each time.

This episode was testing different oils and different oil levels with regard to horsepower. That’s not material to the conversation except oil levels at full in this test produced less horsepower and LESS oil pressure. Seems the crank whipping around a few thousand times a minute will beat the oil into a froth if the oil level is too high. Of course that robs power, but what is relative to this conversation is the other thing that happens. It beats air into the oil, and forms an oil aerosol in the crankcase. In our case, that aerosol makes it’s way to the slobber tubes.

I see the same thing on my Series 60. Until @rheavn told me 36 quarts, not 40, I was adding an extra gallon each oil change. And seeing the front of my toad rustproofed each trip. As soon as I started with 36 qts., the toad oiling ceased. At 40qts the oil level was just barely over the full mark so the dipstick was no help in figuring out how much oil the engine actually wanted.