Catch can, or free breathing?

[wrx_lou]

As title, just wanting a bit of advice as to which would be the most beneficial. Also is there any point to getting a can with a breather, or will sealed be fine.

And lastly, anyone know where to buy a good one from?

[EJ20T]

Word of warning, vented cans stink! if u go vented u need to remove all original parts of the breather system, and block the PCV valve

[Guest dynofiend]

On a side note, generally cars will run better with postitive crankcase ventilation as compared to an open to air system. Some PCV systems are pretty complex to increase performance and also reduce emissions at the same time.

Heres some intresting bedtime reading for anyone who wants to know more about it http://www.106rallye.co.uk/members/dynofiend/breathersystems.pdf

[wrx_lou]

so a sealed would most likely be better, and easier to install?

[Optical]

not sealed obviously, but returned to you intake

[nzkaosnz]

i thought oil vapour reduced effective octane level?

[BC5RA]

 nzkaosnz said:

i thought oil vapour reduced effective octane level?

It does; but the idea is to vent gases into a sealed catch can that is filled with fine steel wool to have the oil collect on.

Thereby rendering the air passing through much more clean.

[Guest dynofiend]

mmm, steel wool wouldnt be my first choice. A small chunk of that breaks off and itll get ingested straight into your engine. Best to use a combination of expansion, labrynth, and maybe passive centrifuge type design in your catch can setup. All very easy to do.

[Koom]

 dynofiend said:

mmm, steel wool wouldnt be my first choice. A small chunk of that breaks off and itll get ingested straight into your engine. Best to use a combination of expansion, labrynth, and maybe passive centrifuge type design in your catch can setup. All very easy to do.

Yes especially when the engine starts sucking air back through the breather system. Even the grimy yellow sludge in my breather gets sucked about 100mm down the hoses back towards the engine, so would hate to think how quickly small bits of steel wool would go back through there.

[BC5RA]

 dynofiend said:

mmm, steel wool wouldnt be my first choice. A small chunk of that breaks off and itll get ingested straight into your engine. Best to use a combination of expansion, labrynth, and maybe passive centrifuge type design in your catch can setup. All very easy to do.

Good advice, will empty mine and refill.

Cheers.

[kamineko]

mmm yellow sludge

my attempt, hand filed and tapped. collects condensation and oil, works fine.

[Guest dynofiend]

Spot on that Kamineko. Heres one I made a few years back. Cost about $15 for the parts, and was extremely lightweight too.

[DRFVDR]

on that note

Old fireextinguishers amke good catch cans

[Jammasta]

 dynofiend said:

Spot on that Kamineko. Heres one I made a few years back. Cost about $15 for the parts, and was extremely lightweight too.

Haha, is that one of those alloy drink bottles? Looks pretty decent.

[subieboy]

 DRFVDR said:

on that note

Old fireextinguishers amke good catch cans

Know where we can get some old ones (empty and de-pressurised of course)

[gtlegacy]

ok so is there an oil seperator built into the rear of crank case of the ej20 engine?

if not im keen to make 1 or even a catch can as a project

when installing it do i pick up my intake from the2x breathers in the heads and off the rear crank case (the one that connects to pcv valve i think under the throttle body)

onto the in of my seperator or catch tank and then run the out (clean air) from there into the pcv valve under the throttle body ? where does the line from the intake go from there ? tee it into the out and put on the pcv valve?

can somebody tell me if thats correct or not?

[Guest boostin]

There is an oil/air separator, its the kidney plate. Its pretty basic though.

[Guest]

as to where to get them Lou-Jap Race (Aucks and Chch) do polished ones with anodized fittings,Trade Me has them,Ebay has them etc etc

[nzkaosnz]

cheers.

May pay to check last date thread was replyed to to ensure not dragging up old stuff

[wrx_lou]

haha, yeah i've long since fitted one

thanks anyway though.