Oil catch can for GTR

[Mik]

In an effort to keep avoide even more hoses running accross my engine bay, I'm thinking about only running one 3/4inch hose from the rocker covers (using the OEM joiner hose) to the catch can.

Will this flow enough? I'm guessing that it will, because from factory, all they have is one 19mm hose and another one going to the PCV valve which is pretty small and wouln't flow much anyway.

[Sydneykid]

  Mik said:

In an effort to keep avoide even more hoses running accross my engine bay, I'm thinking about only running one 3/4inch hose from the rocker covers (using the OEM joiner hose) to the catch can.

Will this flow enough? I'm guessing that it will, because from factory, all they have is one 19mm hose and another one going to the PCV valve which is pretty small and wouln't flow much anyway.

The PCV valve opens under vacuum (ie; when the throttle is closed) so there is PLENTY of sucking making up for small holes.

Back to the question at hand, as long as you run the cam covers linking hose there is no problem with only running one vent hose to the catch can.

[Beer Baron]

so you could have one hose from the cam covers going to the can, and one from the can venting? or returning the vapour to the inlet (pre-turbo, or post turbo - i've seen both)?

[blind_elk]

If you are venting it to the inlet plumbing, then the can needs to be sealed, otherwise the inlet simply pulls (un-metered) air through the can vent. And you probably want it returning PRE-turbo, otherwise you'll blow all the air back through the can under boost.

[Beer Baron]

yep, that's what I was thinking. non-vented can. run one (bridged) line from the cam covers to the can, run one from the can to the turbo inlet (post AFM, pre-turbo). the ones I've seen post turbo use a one way valve to prevent the boosted air blowing back through the can and pressurising the cam covers. doesn't seem worth the bother though.

[williamsf1]

This is my catch can set-up....

red arrow = pipe to turbo inlet blocked with bolt

yellow arrow = standard connection

blue arrow = 2 connections as seen one going to yellow arrow, the other to catch can

then there is the 2 pipes bought from pirtek going to catch can with K & N filter on catch can...

catch can is chock-a-block with stocking filled with stainless steel wire/mesh

I think this is right... I am sure SK will be able to advise

[JH32]

where did you get that can from ben ?

looks nice !

[williamsf1]

I had it made.... was a spun up bit of alloy from a guy down at the Gong... and then lesuire coast welders.... they made up the rest... with welded 20mm pipe attachments and filter...

I made up the brackets and the pipes etc....

all up about $180

SK knows the site for the alloy bit I have forgotten it sadly....

so is it hooked up right? I have left the PCV I think, but no nasty fumes going into the intercooler which is what I wanted.....

[Micko]

I've been running mine with only one pipe to the can as you are suggesting for ages - works fine;)

[calais25t]

Whats the point of a catch can?

[horn]

Looks like you will have an 'air leak' at idle with one hose hooked up to the pcv .

As the catch tank is vented.block off the pcv.

[bfi.inc]

Perhaps the distinction should be made between a catch can and an oil air seperator. Personally i only ever use a oil air seperator

[Boosting]

wow im so confused right now.

I was gonna do mine the same as williams but didnt know i need to block off the last one.

why is that

[Boosting]

and what size hose is that were can i get it from.

how much pressure usualy runs through those hoses.

sorry guys im not sure

[williamsf1]

ok I got my hose from pirtek at about $20 a metre it is generally used for air-compressor line, but seems to fine in this application also (having seen a few race cars running it, and it is hardly stressed with pressure etc etc....)

I'm wondering if someone (SK) can come and explain using my colour coded pic if my setup is correct? I can't see why having the factory pipe (yellow) is bad???

thanks

[Sydneykid]

  williamsf1 said:

This is my catch can set-up....  

red arrow = pipe to turbo inlet blocked with bolt

yellow arrow = standard connection

blue arrow = 2 connections as seen one going to yellow arrow, the other to catch can

then there is the 2 pipes bought from pirtek going to catch can with K & N filter on catch can...

catch can is chock-a-block with stocking filled with stainless steel wire/mesh

I think this is right... I am sure SK will be able to advise

My suggestions;

1. The catch can plumbing is OK.

2. (Red Arrow) Blocking off the breather to the inlet (between the AFM and the turbo) is OK. This stops any oil mist getting into the turbos, pipework and intercooler. This is a good thing as the oil mist condenses and acts as an insulator which stops the heat transfer out of the inlet air in the intercooler.

3. (Yellow Arrow) Keeping the PCV valve (and its plumbing) connected will mean that oil mist gets into the combustion process when the engine is not on boost. The main propblem with oil mist is that it promotes detonation on boost. So continuing to use the PCV valve means any oil mist on overrunn will get burnt as per the standard PCV process.

(A) You could simply block the PCV system off and remove the standard plumbing, that way all oil mist will go into the catch can.

(B) You could replace the filter on the catch can with a hose that connects to the PCV valve. That way any oil mist will get trapped by the stainles steel wool in the catch can and not get into the combustion process, ever. You would need to disconnect and remove the standard plumbing from the RHS cam cover to the PVC valve. This is a totally closed system (not open to ambient air), so it would be fully legal.

That's the 3 ways you can run a catch can, you currently have 50% plumb back, (A) is 100% open to atmosphere, (B) is 100% plumb back.

Hope that makes sense:cheers:

[williamsf1]

ahhhh guru!

well I don't want any detonation....

ok, so if I keep the pipe to the PCV and block it like I did to the turbo inlet that does pretty much the same thing....(bolt inside with hose clamp)

2moro's job!

yes I know still another week till I actually have to do some real work

[Boosting]

question if i do it the 50% plumb back way is it legal..

Im not sure and just fitted my catch can.

Dont want to give the police another reason to spank me

and if i dont block off the pvc to the intercooler pipes will the catch can still work.

or is it better.

Catch can has steal wool in it.

[Sydneykid]

  Boosting said:

question if i do it the 50% plumb back way is it legal..

Im not sure and just fitted my catch can.

Dont want to give the police another reason to spank me

and if i dont block off the pvc to the intercooler pipes will the catch can still work.

or is it better.

Catch can has steal wool in it.

Only 100% plumb back could be considered legal.

[super26]

  Sydneykid said:

The PCV valve opens under vacuum (ie; when the throttle is closed) so there is PLENTY of sucking making up for small holes.

Back to the question at hand, as long as you run the cam covers linking hose there is no problem with only running one vent hose to the catch can.

is it a good idea to block off the pcv valve when installing a catch can or jus leave it connected.