Outer Limits 4x4 Board

when fitting oil catch can to a 4.2td between the turbo and rocca cover, does the catch can need to be completely sealed or can it have an air filter fitted to it?

You have one pipe from the rocker cover and one from the intake with the catch can fully sealed. This is done for two reasons:
*It is illegal to vent it to the atmosphere.
*It will stop water/mud/dirt entering your engine through the oil or the intake.

It's best to have it sealed.
mud, dirt and water ingress are not desirable, also just incase some nasties happen you'll pump oil everywhere and risk a fire hazzard if it's vented.

Where do you put the return from the catch can ? Back into the sump ?

I am noticing a fair bit of oil building up around the silicon bends on the intake side of my turbo on my pootrol. I have a feeling it is coming from the rocker cover breather pipe that goes to the main cast intake pipe.

Can someone much wiser than myself give a decent howto on bunging in a catch can ?

JemmyBubbles wrote:Where do you put the return from the catch can ? Back into the sump ?

I am noticing a fair bit of oil building up around the silicon bends on the intake side of my turbo on my pootrol. I have a feeling it is coming from the rocker cover breather pipe that goes to the main cast intake pipe.

Can someone much wiser than myself give a decent howto on bunging in a catch can ?

You put the can on that pipe you are talking about. Between the rocker cover breather pipe and the main cast intake pipe.

The can is just emptied when it gets some oil build up inside, you don't put it back into your motor. If you are getting way too much oil in the can, something else needs to be looked at.

JemmyBubbles wrote:Where do you put the return from the catch can ? Back into the sump ?

Yes.
Unless you like emptying it yourself.

what i was trying to do was put the catch can in and have the intake for the endless air compressor coming from the catch can. i was also going to put a little filter on top. is this OK?

chips59 wrote:what i was trying to do was put the catch can in and have the intake for the endless air compressor coming from the catch can. i was also going to put a little filter on top. is this OK?

Why? You are then possibly sucking in oil contaminated air

SEAL your catch can, and have the intake for the ndless air in your airbox or use a seperate filter for that instead of the catch can. Did I mention it needs to be SEALED

HotFourOk wrote:

chips59 wrote:what i was trying to do was put the catch can in and have the intake for the endless air compressor coming from the catch can. i was also going to put a little filter on top. is this OK?

Why? You are then possibly sucking in oil contaminated air

SEAL your catch can, and have the intake for the ndless air in your airbox or use a seperate filter for that instead of the catch can. Did I mention it needs to be SEALED

he wants the oily air from the crank case to lube his compressor.

ok, lets look at it another way. can the tube coming from the rocca cover go to the catch can and the other end be blocked off?

KiwiBacon wrote:

JemmyBubbles wrote:Where do you put the return from the catch can ? Back into the sump ?

Yes.
Unless you like emptying it yourself.

I wouldnt recommend this at all. Echo the above comments on just emptying it every once in a while. If its filling too often there are obviously bigger issues. My last catch can had an indicator on it so that made things easier, only emptied it once over a few years!

My reasoning for not draining back to the sump is simple. The shit that accumulates in the catchcan is seriously dirty sludge, I wouldnt even call it oil anymore. Why would you want to drain that back into your motor!?!

Rb25sil80 wrote: I wouldnt recommend this at all. Echo the above comments on just emptying it every once in a while. If its filling too often there are obviously bigger issues. My last catch can had an indicator on it so that made things easier, only emptied it once over a few years!

My reasoning for not draining back to the sump is simple. The shit that accumulates in the catchcan is seriously dirty sludge, I wouldnt even call it oil anymore. Why would you want to drain that back into your motor!?!

My Isuzu 4BD1T has a factory catch can that drains back into the sump. Other engines have exactly the same setup, just built into the rocker cover instead of an externally mounted can.

It's not "sludge", it's simply oil mist carried by blowby gases out the rocker cover vent.
Given that the Isuzu's would do half a million km's between rebuilds like this, I don't see the problem.

chips59 wrote:ok, lets look at it another way. can the tube coming from the rocca cover go to the catch can and the other end be blocked off?

There will be pressure build up in the can, so if the intake hole is blocked off, you need a filter on the can to vent the extra pressure which usually flows back into the intake piping, which you don't want to do.

So I vent it into the passenger footwell

Just wondering if anyone knows where to buy a decent catch can? Have only seen the smallish ones at supercheap etc.

JemmyBubbles wrote:So I vent it into the passenger footwell

if you want to kill everyone in the cabin, go right ahead.

vent it back into your intake pre-turbo. THats what you are required to do by law, and its also the best spot to do it anyway.

Shadow wrote:

JemmyBubbles wrote:So I vent it into the passenger footwell

if you want to kill everyone in the cabin, go right ahead.

vent it back into your intake pre-turbo. THats what you are required to do by law, and its also the best spot to do it anyway.

Yes, I plan on killing everyone inside the cabin

JemmyBubbles wrote:

Shadow wrote:

JemmyBubbles wrote:So I vent it into the passenger footwell

if you want to kill everyone in the cabin, go right ahead.

vent it back into your intake pre-turbo. THats what you are required to do by law, and its also the best spot to do it anyway.

Yes, I plan on killing everyone inside the cabin

Well there are better ways to do that go get that hose on ya vacume cleaner and connect it to the exhaust seal the windows start the car.

foster_the_fat wrote:Just wondering if anyone knows where to buy a decent catch can? Have only seen the smallish ones at supercheap etc.

You don't need a big catch can... if you do something is wrong

I have a Suprecheap unit and it does the job very well, without breaking the bank. ~60 bucks
You can try Repco, Autobarn and any performance shop. Even eBay has a lot of variety. The baffled types help to seperate the oil from the air.. the supercheap ones are not baffled inside. The other units I saw were $180 and upwards, I couldn't justify that for my old chugger

You don't need a big catch can... if you do something is wrong

quite a few vechiles, exspecially older ones wil need a resonable size one as they get lots of blowby.

biggest thing is to make sure it flows well enough, otherwise it wil act like a restriction and pressurise the motor, not good.
check the internals, some of them drop the pipe sixe internally :( and some of the baffels ones have very por gas flow. a non-baffle one might be better.

Baffles suck.

Make one like a cyclone that throws the oil out onto the walls of the can. It's the best way to seperate oil from air without a big restriction.