Water has gotten into crankcase and Oil

[ndutton]

My experience is a small diameter vent hose provides enough restriction that a metering valve is not necessary. One less part. I forget the size of my vent hose, something like 5/16" I think.

The tricky part is finding a place to discharge the spittle that is open to air. Usually a galley sink is the answer. Joe, your drawing has me concerned. The arrangement of discharging the spittle to a below the waterline thru hull works when the engine is running but will not allow air into the loop freely when a siphon tries to start (vacuum dynamic). That's the reason I mentioned the end of the vent hose needing an open air connection. Mine connects to the galley sink drain at a point above the waterline.

edit
Disclaimer: maybe "thru-hull" on the drawing doesn't mean what I thought it did.