I know of a couple other forum guys that have installed the external breather systems and have routed the hoses up over the throttle body and do not use a catch can and have not had any oil drips. The theory is that gravity will drain the oil back into the motor.
I’m not to sure is that is a good ideal since the umbrella valve is also a check valve which does not allow reverse air flow into the motor. A common way to check the umbrella valve is to connect a hose to the breather bolt and you should be able to suck air out and not be able to blow in.
I been waiting to talk to them to see if they are trapping the oil at the breather bolt cavity which is acting as a catch can.
But then again, the umbrella valve should not let any oil through it and I have always wondered could the oil coming out of the breather be caused by the high suction of the air box sucking the oil out of the motor. I think this might be the case due to what I have seen captured in the catch cans shown on the internet. It looks more like a brown muck which looks more like condensed oil vapor rather oil droplets.
and my pondering continues
