Air/Oil separator (catch can) plumbing

[ke_25]

Motor is a 20v 4age turbo for reference, running the quad throttles.

I am getting an air/oil separator made (similar to this http://www.moroso.com/catalog/categoryd ... code=18549) and was just wondering about the return line.

I am doing away with the factory PCV and will be suing a 1-way valve built into the catch can. My question is, for the return line, does it matter where the return is located? I guess, like factory, it should be plumbed after the throttles so that there is a form of vacuum there?

Is this correct? Or will it be fine pre throttles? I tried to google and couldn't really find a sample with ITBs.

Cheers in advance.
Shaun

[gt4dude]

the way most people do it is to delete the pcv and run all breathers to the 1 catch can with a mini k&n, for motorsport you'll need atleast a 1L can

with that little gadget you have there it looks like its to be run inline with the stock sealed system, you cant just delete the pcv and have a return line at a vacuum source or the engine will idle high

if you really want to return, you'll need a plenum, or better yet, why not just have a drain hose back to the sump?

[ke_25]

It is street car, and i have been told that due to emissions laws you can have trouble getting cert with an atmosphere breathing catch can. Hense the return.

The idea is to allow the 'clean' air to recirculate back into the motor, without the oils residue that can occur if you dont run one. I do have a PCV valve as such, that what i am using the 1-way valve for. My question was does the catch can need to be plumbed into a vacuum source, or can i merely circulate it back into my plenum (before the quads).

[sergei]

PCV valve is not 1 way valve .

[cat007]

PCV valve is not 1 way valve .

?

[matt dunn]

PCV valve is not 1 way valve .

?

A PCV valve is more of a flow regulator than a one way valve,
if you take a PCV valve out and replace it with a one way valve,

expect the car to suck heaps of oil into the intake at idle,
and probably eventually suck all the oil seals inside out and make it leak like a sieve when parked up, like cars with dry sump setups do.

[gt4dude]

what i'd do is have a can made up with all of the valve cover ports leading to the top of the can, a drain port at the bottom going back to the sump, and the top port can be your mini k&n filter

for inspection, replace the mini k&n filter with a hose running back to the air intake by the main k&n filter.

and yeah the pcv is a funny little device, from what i understand the conditions it needs to open is high pressure from the bottom (crank case) and atmospheric pressure at the top (intake manifold with light throttle, light load, no boost, no vac)

so basically the pcv has to stop boost going in _AND_ vacuum sucking oil out

[ke_25]

i see. Interesting. This is exactly the information i was after!

So does anyone know anybody who does -an fitting PCV valves? Or at-least inline valves?

And if not. Will the factory valve be fine with added boost?

[gt4dude]

the valve is not necessary as you will no longer have a line going to the manifold

this is what im doin anyways

[cat007]

Would you put anything in this can to help condense the vapour? If so, what?

[gt4dude]

doesnt matter if its not going into the intake, if it was full time plumbed back into your intake you would have a separator plate between the feed and the vent and the bottom half would be packed with steelo