wallra

A) PCV INTAKE this is where vacuum pulls the air in to take pressure from engine B) intake vacuum positive suction for pcv E) connects engine breather to oil tank (engine pressure)

Gus

above is link to 1 way valve I used / has AN 10 fittings each side which perfectly in crank case vent hose.

Gus

Just realized the link is to an AN 6 fitting, you want the one way valve with AN 10 fitting.

revolve40

I took a stab at a catch can set up following Gus’ lead, but found that this exacerbated oil leaks at my right hand side valve cover. I’m sure it has something to do with the check valve. Seems to me this may be increasing crankcase pressure prior to it cracking the valve open back to the tank, which may be causing leaks.

Thoughts? Wondering if I can just run this set up but without the check valve.

Please excuse the filth and blue zip tie - black ones on the way but wanted to test things out.

I blocked off the two openings pre and post throttle butterfly, and ran those two lines from the tank to the catch can.

Gus

Is the check valve installed in the proper direction. The air flow should be out not in.
it sounds like the direction is in with the valve cover issue. On my car I had a small seep on the front seal, but when I installed the check valve the seep stopped. The one way check valve should create negative pressure within the engine.

revolve40

Yes - if you check my photo the arrow indicates flow, which is from the engine to the oil tank. I’m just concerned that the valve requires a lot of pressure to open, and that pressure builds up inside the crank case.

have you tried this set up without a check valve in the crank case hose?

Gus

The pressure needs to be on the weak side for the check valve. You should be able to blow it open with little pressure.
no have not tried with out check valve- but should function the same just no negative pressure buildup in crankcase.

revolve40

Given my issues with the previous approach, I went back to stock but with a catch can in line between the intake manifold behind the butterfly and the oil tank. We’ll see if this actually catches any oil.

kevin2012

Your oil catch can looks very professional. May I ask where did you get it and how much?
I had tried this setup before but still found oil in the intake (oil not over filled). Looking forward to hearing from you again for the result.
Cheers

revolve40

Thanks, Kevin - this can is from Radium Engineering. Unfortunately, like you, I still have oil in the intake. It must be getting in from the line from the tank to before the throttle body.

Wondering if I can run a second in-line catch can there… trouble is finding one with big enough fittings for that large hose without creating a bottle neck in the venting system. Any thoughts would be great!

abarthguy

More amazing is that you live in Tennesse and don't have air conditioning!!
Thanks for the deep dive into breather lines!

kos11-12

Hello there,
Did you resolved your issue ? Could it be a faulty return valve ?
Thanks

revolve40

The valve worked, but I suspect it required too much pressure to open, causing a buildup of crankcase pressure which exacerbated existing oil leaks - not sure if this is what was happening but makes sense in my mind. I ended up removing the valve and going to the in-line catch can set up mentioned above. I think I'm going to add another can between the tank and the inlet before the throttle body as I'm still getting oil in the intake.

I do think, however, that this issue is more directly tied to a tired motor with excessive blow-by vs. a fault in the breather design. I'm just trying to indirectly address my symptoms.

HiWind

@Gus last question - did you remove either of the restrictors in the 2 oil tank pipes which you vent to catch can??

Gus

No - basically all lines fittings going tank remain stock- only modifications were adapters to allow hose fittings