PCV & Crankcase Vent Modifications

[2053.media]

Hello everyone, I’ve been slowly modifying my stock pcv/crankcase vent system because of some issues I was having. I started with a radium catch can for the vent that goes to the intake manifold. I also have a 2JR intake with the other crankcase vent routed there. The intake-side does not have a catch can since I’ve never really had much oil go through there in the first place. Do note that these two mods were done before I had any issues.

Everything was great until the car started burning oil on decel after high-boost pulls. So, I did some digging and asked a lot of people and concluded that it was something related to the pcv as I found a LOT of oil in the pcv line that goes to the intake manifold (even though I have a catch can…) My guess was that the pressure inside the motor had nowhere to go and ended up shooting through said line straight into the manifold. Also, I think boost might’ve been creeping up into the pcv line and into the catch can.

To test, I went and got a cheapo autozone oil cap breather replacement and wrapped a towel around it to prevent oil from spraying through. This worked and stopped the issue I’ve since gotten a baffled breather and a check valve for the pcv line that goes back to the intake manifold and the issue still hasn’t returned (thank god).

To figure out a more permanent fix I wanted to get some feedback on a possible pcv breather. This would involve turning the existing catch can into a catch can with a breather and completely deleting the side that goes to the intake manifold.

Basically, instead of

Valve cover vent -> Catch can -> intake manifold

it’ll be:

valve cover vent -> catch can -> atmosphere

What do you guys think?

 

[Mega ST]

I personally don't care for the VTO catch can as most of the fumes end up in the cabin after a pull. Tolerable on a dedicated race car, but an annoyance on a DD IMO. In my DSM days I recall running the vent line to a line attached to another catch can that ran to a vacuum source. I had to empty the 2nd can every once in a while to prevent smoke out of the exhaust. In another scenario I ran a line from the top of the catch can vent outlet to somewhere underneath the car with a vent filter there where fumes did not enter the car.