Can some please explain to me how the PCV system works in particular the crancase vent.

I'm trying to sort out how to safely / correctly connect a catch can.

This is my understanding...
On the crancase vent there is a y - piece attached (may have some type of valve) One pipe goes to the PCV valve on the intake manifold - the other to the intake - pre turbo. During engine vacuum the PCV valve opens creating a vacuum in the pipe connected to the y- piece causing the y- piece valve to open and vent the crancase gases into the intake?? Is this correct.

Is it ok to connect the catch can to the crankcase vent (pipe going to inlet off y-piece) and to the rocker cover vents?? Thus combining both systems.

Alternatively can you scrap the PCV system all together and have the crankcase vent into the catch can all the time - will this cause any problems.

Why am i so confused - i received this image from Roger Clark Motorsport regarding the installation of there catch can. As you can see he has the vent for the crankcase connected on the wrong side of the y - piece "I THINK" Can someone pls verify.

http://i49.photobucket.com/albums/f2...tion2Large.jpg

Many Thanks

Anthony

See explanation in RED

Slightly off topic, but you bought a catch can from Roger Clark Motorsport in the UK??

If so, can we see a photo of it? If its anything like the rest of the stuff that comes out of that workshop, its awesome

off-topic and hijacked, what u want is something custom like this sucker. you don't want no mass produced oil-air seperator, be no different than those dodgy greddy spec china knock off jobs, worthless. okay, so its a little more expensive yes, but you not only get something that actually works, but looks a million bucks too (hopefully without costing it) and its a one off which no-one has got.

http://members.iinet.net.au/~asupply...136_3683_1.JPG

Thanks for all the replys.

Balistic - I'm considering purchasing a Roger Clarck MotorSport Unit, but 175pounds its expensive plus another 33pounds for a fitting kit. Over $500 Aus just for a catch can!!!!

BluWRX - Thanks for your explanation. I just received an email from RCM indicating they vent all crankcase gases to the catch can and block off the other opening on the y - piece.

If i connect the can this way i assume i just remove the PCV valve from the manifold and block with a bung ??

In terms of a "stinky" car as mentioned - if i vent the can back into the intake dont i get the best of both worlds - no PCV Valve and no smell.

WRXRW - On the custom catch can pictured have you removed the PCV valve from the system all together?? I also noted you are venting the gases to atmosphere - isn't this illegal on the streets??

Thanks

Anthony

Ramon's car isn't really street legal with a full, weld in roll cage amongst many other modifications.

Thats not the RW. But what do u class 'street legal' when modifying a car?

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www.racewars.com.au

Oh, is that lockharts car?

yeah that's not my bad boy oil-air, this is...

http://www.cheekei.net/gallery/displ...lbum=43&pos=26

it doesn't have to be so difficult, one crank and two cam vents, three hoses and plug up everything else, otherwise, as jmax rightly pointed out, you bypass the use of having a seperator in the first place. illegal vent to atmo, mmm, not sure, could be.

yeah ive heard venting blowby to atmo is illegal, something to do with it containing oil vapour

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MY93 Impreza GX 1.8L, 0hp, 0nm