lazerus

Any good Crankcase vent system will have a vacuum pump to evac the gasses all the time, even when on boost.

tinkerbell

depends on your rocker cover type doesnt it.

a VTEC one only sucks in and has PCV valve in the IM.

a B18/B20 has the PCV valve on the rockercover...

the air goes into the crankcase and should get sucked by vacuum into the intake manifold - on it's journey through the crank case the air picks up oil vapours

it really is that simple.

t..

servion

So, (using a atock b18c as an example) if the air travels in through the valve cover and out to the IM via the oil spearation box, then if there's a valve cover breather and the oil-return hose (to the IM) is disconnected and venting to the atmosphere.... will there be a way for the air to pass through the entire PCV system?

There is no air being forced into the valve cover (due to the breather), and there is no vacuum drawing the air out of the separation box.... would this be a bad setup, or will the motor itself somehow direct the air from the valve cover to the separation box?

tinkerbell

with your engine running (preferrably cool), remove the oil cap and place you hand just above the opening.

is there pressure there? is it positive presure? ie blowing

or is it negative pressue? ie sucking

what if you try and seal the opening with your hand?

then think about what you are experienceing, where does it come from? what is happening inside the engine to cause it? how would it relate to a breather/PCV system...

t..

Mover

You don't need the vacuum. The excess pressure will vent out the tube on its own.