2015 V7 Breather Anti-Return Valve Operation???

[LeakyLogic]

I was studying the parts list diagram of the 2015 V7 Breather/Blow-By pipes trying to get a general understanding of how this particular model year works. If it's a vacuum valve that only opens when the engine is off to return oil to the sump, how does the crankcase breath then if the valve is only open when engine is not running? Since the part is described as an Anti-Return valve, I assume it prevents oil entering bottom end until there is no vacuum (engine off), but I've seen translation confusion in Moto Guzzi workshop manuals before. How does the crankcase breathe then? I understand the blow-by pipes allow the top-end to breathe? What is the proper functioning of the anti-return valve? How does this entire system work together? I seem to be missing some piece of the puzzle.

[John Warner]

Does it not just prevent reverse flow of Breather fumes (i.e. back into the Engine)?
If not, then what's the point of fitting it?
I'm guessing it's the same as a PCV (Positive Crankcase Ventilation) Valve on a car.
You don't want the water vapour and/or combustion by-products returning to the Engine, you want them to go to the Airbox, as planned.

[Vasco DG]

Nah. Engine breathes from two pipes on the rocker covers that go to the frame top tube. This acts as the condensor. Condensate returns to the sump via a hose from the lower part of the frame tube which also has the one way valve in. The upper pipe that comes off the frame tube takes the expelled gasses, hopefully bereft of too much oil vapour, off to the airbox for rebreathing through the engine.

Pete

[LeakyLogic]

Where does the pressure built up inside the crankcase go that is generated from the downward motion of the pistons if the valve at the sump is one way? The rocker cover breathers would only vent above the piston rings, but isn't there always some blow-by into the crankcase despite the best seated rings. This pressure inside the crankcase needs to be expelled to maintain seals and prevent sludge build up from the combustion gasses that blow by the rings into crankcase.

[LeakyLogic]

Thank you. Pushrods, that make sense.

[Vasco DG]

There are two bloody great oil return galleries down the side of the barrels gas vents up, oil trickles down. Have a poke about with a clean screwdriver next time you have the rocker covers off, you'll see.

Pete