Preheating engines: Airplane engines versus auto engines

On Dec 22, 6:43 am, Mike Spera wrote:
When we bring the airplanes in after operating in cold
weather, oil and water emulsion will be found on the floor under the
breather tube the next morning.

I suspect that the puddles have more to do with the fact that breather
outlets tend to be on the top of the engine and are connected to a 3
foot tube running straight down than any gasses purging out of the
crankcase at shutdown (or what the temperature was outside). The tube
walls are coated with a water/oil mix from flight and slowly this drips
down to cause the puddle.

An interesting test would be to remove the breather tubes completely
after flight and see if anything accumulates.

Good Luck,
Mike

That's what I meant. It's not any gases coming out after
shutdown; it's the thickened oil, containing water, that hangs in that
cold breather tube and drips out slowly overnight in the heated
hangar. The water in the emulksion came from combustion blowby.

Dan