Catchcan plumbing question...

[Amaru]

Hi Riceline, in your picture you cut off the 4th connection, the one that goes to the PCV valve on the plenum.  It is on the cam cover juts down from the blue one in your picture.

If you open up the angle of the photo a bit so we can see the inlet plenum, then I can draw on your picture the choices you have for plumbing up a catch can.  Yes that's right you have CHOICES, there is not a wrong and a right.

Id be extremely interested in seeing this too, I assume itd be along the same lines for a GTR? Looking at putting one on, what would be the best way of doing it?

[Sydneykid]

Id be extremely interested in seeing this too, I assume itd be along the same lines for a GTR? Looking at putting one on, what would be the best way of doing it?

Exactly the same for a RB26DETT, or an RB20DET or an RB25DET or an RB31DET (in my case). But keep in mind there is no "best way", you choose whichever suites your requirements.

I call the choices ;

1. 100% plumb back

2. 50% plumb back

3. Zero% plumb back

Anyway, more when the picture is up.

[Ronin 09]

I'll take a pic and upload it tonight...

How's this:

http://www.skylinesaustralia.com/forums/at...achmentid=14761

[riceline]

Hey Sk

here are 2 pictures that you may be able to use. If you need any more or different angles.. Just ask and Ill run out with the Digi cam

Hope these help

[knore]

So what options do/dont u have if your catch can isnt vented?

I have a trust can which is basically hollow but looks cool.. not vented.. u know the one.

Whats the best option for say; 230rwkw or less, running either standard or hiflowed turbo, big intercooler, on 12psi constantly?

I think this suits alot of people...

Is this right?

[riceline]

I just put those pic's up so that SK could mod them mate..

Thats a standard hook up..

[knore]

I know, im waiting for sk to post some so in the meantime i posted my own

[knore]

bump, i really want sk's info in here, catch can threads never get finished

that and i have a cc sitting here waiting to go in

[riceline]

Come on SK come on... come on... come on SK come on....

[Sydneykid]

Sorry guys dead lap top, I'm working on it. :thumbdwn:

[Sydneykid]

Let's try this one, it's the open to atmosphere catch can;

The idea is to only have one connection from the cam covers as they are joined by the standard pipe. The PCV valve and the connection to the inlet before the turbo are blocked off. You can have a return (drain) to the sump form the catch can if you like. Don't T it into the turbo oil return as it is under a bit of pressure and the oil can run up into the catch can.

The other 2 options follow in separate posts.

[R31 POWER]

SK doing it that way wont cause any probs to idling?Don't laugh but is the blow-by metered by the air-flow meter,coz after all it is air that has been metered.What i'm trying to get at but slowly is blow-by the same as air from a bov that is being vented to the atmoshere?

[Sydneykid]

SK doing it that way wont cause any probs to idling?Don't laugh but is the blow-by metered by the air-flow meter,coz after all it is air that has been metered.What i'm trying to get at but slowly is blow-by the same as air from a bov that is being vented to the atmoshere?

Good question R31 POWER, but if your engine has enough blow by to cause idling problems, then it is not the blow by that you should be worried about. :spew:

[Sydneykid]

Sorry for the delay, virus on the laptop :type:

This one I call the 50% plumb back, because half of the time (no boost times) the air from the catch can is being sucked into the inlet manifold via the PCV valve;

It is not my favourite, because you can still get a bit of oily air into the engine, but since it doesn't go in under boost (the PCV valve is closed then) detonation isn't much of an issue. At least you don't get any oil into the intercooler and its pipework.

[Sydneykid]

The last is 100% plumb back, all of the air goes back into the engine. Some goes via the PCV valve, at times of no boost. When there is boost, it goes back via the inlet system, through the turbo, the intercooler and its pipework. :uh-huh:

The idea is the stainless steel wool, helped by the lower velocity in the catch can, catches the oil and removes it from the air before it goes back into the engine. This is the environmentalists favourite :alien: and is the easiest to get engineered.

[JasonO]

SK,

How would you plumb it, if emissions were not an issue, as in a 100% race engine. Metohd 1, 2 or 3 ?

[Sydneykid]

SK,

How would you plumb it, if emissions were not an issue, as in a 100% race engine. Metohd 1, 2 or 3 ?

On the race cars we run open to atmosphere. We do run 2 pipes to the catch can and remove the joiner (standard) pipe between the cam covers. It's not really necessary on a road or combo car though, the one pipe does the job OK.

Hope that helps

[JasonO]

So, would it be acceptable to plumb the PCV line to the catch tank, and leave the joiner as is, with the tank vented to atmosphere ?

[Sydneykid]

So, would it be acceptable to plumb the PCV line to the catch tank, and leave the joiner as is, with the tank vented to atmosphere ?

As long as you block off the unused plumbing and fittings. I gotta ask why though? :confused:

[knore]

Most catch cans only have 1 inlet 1 outlet, so for the ones where u need to attach 3+ hoses to it, do u just use a T piece etc?