I'm building a catch tank for my PCV system to keep oil out of my intake, but I'm not venting to atmosphere. Since I'm recirculating, should the airflow route to the intake (so that it's metered) or to the manifold? I was thinking that it should probably go directly to the manifold since it's dirty air, full of combustion gases and stuff like that, but I'm not entirely sure. Anyone have some clarity?

 

I just went for it and installed it.

Diagrammed out for a friend of mine

Inline filter for an air compressor with the silica pellets removed (replaced with steel wool)

I've noticed that my engine is generally smoother with this attached for some reason. I'm not quite sure why.

 

Droplets inside the clear filter housing look like water??? (based on the way they bead up on the plastic)

When the oil collects inside the big PVC elbow, is there a means to drain back into crankcase?

Now you have a filter on the other vent (on the valvecover), so you can verify that it's pulling air in through that filter. Occasionally (especially at WOT) that flow would reverse.

 

yep, they're water. I'm not sure where that's coming from, but I don't have splashguards and I have a cold air intake, so I might be sucking a bit of water into the cylinders. Either that or it's coming in through the other breather filter. At least it's not green!
As far as the return to the crankcase, I'm waiting until I come up with a better mounting solution before I drill any holes in the oil pan. I'll probably end up threading a small needle or ball valve into the bottom-most section of the elbow and then draining from that into the same jugs that I change my oil into (maybe a section of hose on it to make the process easier?)
Would you recommend putting a check valve inline with the filter on the valve cover?

 

Well, it wouldn't be green because it's evaporated & condensed...

Seriously, any blowby past the rings will have water vapor (combustion product). Maybe it only condenses while that tube is still cool?

 

That would make sense, the filter case is made of glass so it probably drops in temperature fast enough to cause that.

 

You have a separate filter on the PCV air inlet. Normally, this takes filtered air from air intake to crankcase. W/o that connection, crankcase vapors will be discharged through the filter to atmosphere when crankcase pressure exceeds atmospheric pressure (under heavy throttle). This arrangement is unlikely to pass an emissions inspection.

good luck

 

It's okay if it can't pass emissions, there aren't inspections for anything in my county. But that is good to know, it's how I intended it to work.