Catch can on an na

[KarlBristol]

Is it worth installing an oil catch can on a rev1 na?
Will it affect the engine's life span and reliability at all?

[riot68]

I was reading a Jap car mag this morning and saw some for sale and wondered the same thing, although I have no idea what they do exactly haha. Interested to find out...

[MR2O12]

They stop air thats recycled from the exhaust back threw the intake. I was looking into this aswel and think it said somware the acis valves or throttle body one needs some oily air to lubracate could be nonsence

[Super_red]

They stop air thats recycled from the exhaust back threw the intake. I was looking into this aswel and think it said somware the acis valves or throttle body one needs some oily air to lubracate could be nonsence

They stop crank case air going into the inlet not exhaust. I doubt that anything in the inlet needs oil as it will be a brass bearing with a steal shaft or similar.

The only proper way to fit a catch can is to remove the air recirculation all together. Have the crank case breath into the can and then the can breath to fresh air. This stops hot air with oil vapour getting into your inlet. Oil vapour causes octane dilution and we all know hot air is bad for performance. You can leave the can out all together to be honets but its a fail safe to stop your oil ending up on the road should the worst happen.

[Pauln]

I recently changed the induction setup on my N/A and fitted a catch can at the same time.



So now it's just nice cold clean air being fed to the engine. The small flat spot I had also seems to have gone now

When fitting it I noticed that on tick over air actually seems to be being sucked into the catch can on a rev2. I've a feeling later models may have had a one way valve to stop this.

[riot68]

Is this an easy DIY job to do then? I'm still confused...

[Pauln]

It depends where you're starting from and what you call easy.

The blue catch can shown in my photo vents to air via the small mesh filter on top. The only other connection is the blue silicone pipe which connects to the "stock y joiner" that originally plugged into the rubber intake pipe. The two black rubber pipes the other side of the "stock y joiner" are original and simply feed gasses from the crankcase and rocker box into the new catch tank where hopefully any "liquid" oil will gather rather than being splashed around all over the engine. Whether you actually see any oil gather in the tank will I suspect depend on the state of your engine.

Originally the "stock y joiner" plugged into the stock rubber intake pipe and fed those warm "oily" gasses back into the combustion mixture.

If for some reason you want to keep that arrangement, you'd simply have to replace the mesh filter on the catch can with another pipe that simply plugged back into the original hole in the stock rubber intake pipe. So the gasses would be fed via the catch tank where hopefully oil would gather before the gasses were feed back into the combustion mixture.

But you have to ask yourself whether it's a good idea, as you really want to feed nice clean cold air into the combustion mixture, and not added warm "polluted" gasses from your engine.

So I've ditched all the original rubber intake pipework and air filter box, and used a stock 45deg aluminium pipe and two silicone joiners to replace it and to connect the new pipework to a Apexi filter positioned close to the left hand air vent to try to ensure the air is fairly cold. The Apexi filter all ready has a connector for the air temp sensor, so there were no holes to cut, just needed to make up a few brackets to support everything. With a different filter you may need to provide a hole for the sensor.

The hardest part for me was removing the stock filter and pipework, once that's gone you've loads of space to work in.

The catch tank should be mounted in a "cooler" part of the engine bay to try to help the oil content in the fumes condense and gather.

Hope that helps explain the setup.

[KarlBristol]

Is it possible to fit one of these to a stock air intake?

[Pauln]

Is it possible to fit one of these to a stock air intake?

I think later N/A models already have a small catch tank, but if you have one of the earlier ones that don't, it's just a case of inserting the catch tank between the existing vent pipework and the hole in the intake pipe into which it currently plugs.

[riot68]

Already Have a JSP intake system with a K&N filter on fitted so should be easy enough for me, just need to take a look and see if I can figure out which pipe you mean, where did you get yours from BTW, like the blue ...

Thinking I need to make up a bracket for my filter pipe too, let me how you go, was considering trying to make some kind of heat shield while I was at it as well...

[Pauln]

It's almost certainly the pipe that currently goes into the short red silicone pipe just before the intake, unfortunately your rear brace is in the way so I can't see exactly where that pipe goes.

But my guess is that it goes to a y piece with one branch going to a fitting on the firewall between the engine and boot and then back to the pipe on your photo that runs horizontally between your intake pipe and your nice shiny brace (I really must buy one). The other wider pipe on that y piece is quite short and bends to the right where it joins the crankcase. Unfortunately the brace is just in the wrong position on the photo making it difficult to check.

You'll obviously either need to block the hole in the blue silicone pipe afterwards, just make sure you use something that can't be sucked into the intake. Or better still replace it with a new length of pipe without a hole.

I bought the catch can s/h off one of the guys on here, it's a nice solid chunky one. The filter on the catch can came from fleabay, and as you can see the blue paintwork on the top was rubbish, and had all but worn away in a week or two on the car. I've just painted that black today and made an additional bracket to help support the catch can as it's fairly heavy and flexes a bit too much where I have it bolted at present.

I've not supported the metal pipework at all but have two brackets on the filter assembly which keep everything nice and solid. I've not gone the whole hog and fitted an additional heat shield around the filter. It's pretty close to the air vent, so I suspect a heat shield wouldn't make that much difference for the work involved. Though when the bits arrive my intention is to fit a scoop on that side which should also help to keep everything cool in that area. I think the main thing is to make sure the main filter and the catch can are in a cool airstream but clear of the rain runaway from the engine lid.

[riot68]

Ok great thanks for all the help, sounds easy enough, only other pic I have at the mo is this...



Not much better, will take some more when I get chance, still raining here today.

Guess all I need is some vac house with a 10mm internal?

[Pauln]

No problem. That should do it, but you may find it's a tight fit on the Y connector and needs to be eased a bit.

[riot68]

Ok, am gonna have a fiddle about when I get time and weather better, also got to find a can I like too...

[riot68]

Ok so planning on buying some stuff to fit, just need to know I'm getting the right stuff, so is the thing that will join to the hose that then attaches to the can, other opening on the can has a filter and vents to the air? Am I getting this right?. cheers...

[Pauln]

Yep that's exactly the same arrangement as I had on mine.

You just unplug that metal y piece in your top photo that goes into your red intake pipe and connect it to one input of the new catch can via a new length of rubber or silicone hose. You then fit a small air filter on the other input on the catch so the can is able to vent to air.

Catch cans seem to come with two or three inputs. Mine had three so I had to fit a rubber bung in the spare input.

Don't forget to either block off the hole you've left in your intake hose, or better still replace the hose with a new one that doesn't have a hole.

Job done.



Paul

[riot68]

Superb, just what I wanted to hear, will get some stuff ordered, do you.know what size inner diameter hose I need for the Y piece, is it 10mm?...

[Pauln]

Sorry, not off hand. I used a length of silicone hose that came with the catch can. But i remember the fitting on the catch can was smaller than that on the ypiece, so I had to stretch the hose to fit and use a bit of lubricant.

Paul

[riot68]

great, going to do some measuring up and go from there. thanks for all the help...

[MR2O12]

My car seems to have the standard catch tank neer were pauln put his. Are you ment to empty these? Why make a problem then make a soloution to it lol. I dont understand