I didn't mean to imply that my can fills up after one drive -- it takes a few weeks. This is a problem, however, because I do plan to drive the car on the track, and I'm guessing that It'll puke a lot of oil during a long session. I don't want to find out the hard way that it blows too much.

Even if I didn't track the car, this setup would keep me from having to drain the catch can every week (I think).

Air / oil separators rely on the blowby passing over internal surfaces which causes the denser oil droplets to stick to those surfaces and drop to the bottom of the container. Here is a link to the M-20 website --> http://www.m-20turbos.com/content/pr...?link=breather. There are other brands and designs available, but they all use the same principle. Aircraft Spruce carries many of them.

 

i always vent my crankcase pressure from the bottom of the rotor housings

 

^^^ Huh?

 

This topic has been covered since the inception of this forum with countless attempts to solve this issue, some good and some ridiculous but none completely solve the issue.

I have the ultimate solution to the catch can issue. This method TOTALLY eliminates any oil pushed into the tank, period. This method can also be setup vented back to the engine as the OP wants.
Post #205 and on for install pics and explanation.
https://www.rx7club.com/forum/showth...iminate&page=5


The angled flange below the spark plugs provides an area to drill a hole and tap a fitting into to vent the pressure. Not exactly where I'd do it since on long right turns under boost, oil might still get pushed up.

 

Interesting!

 

I've never run a catch can and never have any issues. I drilled a hole in the oil filler cap, run high boost and never any oil blowing out of there. What am I missing here?

 

Drag racing doesn't involve turning, at least the last time I checked. I know you have open tracked your car once or so and it sounds like you didn't have a problem then either. There are several possibilities why; there might not have been the type of corner on the track that induces blowing oil (long right handers). There is minimal blowby due to running low boost and/or your motor is really tight and the third scenario, you were driving like a ***** through the corners

 

Of course it involves turning, how do you think you get back to the pits?

I think it was the third scenario!

 

I like RX-Heven's solution of venting from the front cover. Has anybody else done this? Results?

 

this is a picture of a vented can which allows you to x the pcv
and here is the closed system catch can from greddy(we all know this one)

 

You just have to make us look stupid dont ya!

 

I made a catch tank that fills the void from the original vacuum tank on the seq. setup. Made a few for some other guys on the forum as well. Works really well for me, the filter does get dust caked on the filter, but beyond that it works really well.

 

My catch-can setup uses the two 5/16"-ish crankcase vents plumbed into a januwine Harry's Hot Rod billet aluminum catch can that's mounted on the driver's side strut tower (bottom right corner of this picture). The one thing it doesn't have is a filter, yet.