Pics and vid to follow once parts arrived

Parts needed:
Oil Catch can
3/4" ID 90deg silicon vacuum tube
1/2" ID Oil/Fuel Pipe roughly 1m long (depending on location of can)
Breather filter (Size dependant on your can)

I've been looking into this and have found this mod is only necessary on pre facelift engines.
At the front of the Rocker on pre facelift models there is a pipe that comes out and goes around the front and up the right hand side. This then joins up with a pipe that goes into the induction system.




On the facelift model, where the pipe would come out the rocker you will find it has been welded up. The pipe that comes out the induction is actually now one pipe without a joiner and goes under the induction. Some facelift models may even be fitted with the clips for the metal pipe on the rocker for some reason.


I have tried using a connecter to join the 2 induction pipes together but you get a kink in the pipe which isn't good.

So I then bought some vacuum tubing and tried that, however yet again due to the bend the pipe kinked. So now I have ordered a 3/4" ID 90deg bend to replace the pipes.


Next I chose to mount my catch can on the bracket that was left coming from the slam panel where I had removed the air box.


By removing the clips holding the metal pipe to the rocker cover(10mm bolts) you can remove the pipe and discard of it. Unless of course you wish to keep it on and take the pipe from the end of it.
Next you will need 1/2" ID pipe. Ideally you will need fuel/oil pipe otherwise over time the pipe will deteriorate and leak. However I'm inpatient, and as I don't want black pipe I will be fitting red silicone vacuum tubing. Nice and cheap to replace, however Samco do now produce coloured fuel and oil hose but at £60 a metre it's out of my reach for now so £4.50 a metre vacuum tube will do the job.
Take the tube from the rocker to the oil catch can. 1 metre of pipe should give you plenty to play with but measure it up yourself as your's may be different.



Finally on the other pipe connector of the oil catch can fit a breather filter. I am fitting a k&n as that is what was immediately available to me, but yet again there are cheaper versions on ebay that do the same job. As for the size of the filter it all depends on the size of the connector on your can.

Video!

Really good guide Paul... I have a slightly different catch tank so when I get round to fitting it I will do a guide and add it to this

Cool.nearly got the parts i need now.the 90 deg elbow here just waiting for the straight length now then i can finish it

Updated

Ok so I made a little change to the setup. The pipe from the rear rocker cover is now joined to the front rocker cover and oil catch can. I haven't noticed any negative effect to performance and now I only get clean air into the intake, which will also prevent the massive crappy oil build up on the throttle body. See pic:

Thank you so much, great guide and I'm sure I'll need to refer to it.


I'm not sure how to identify whether or not my car is pre facelift, except that I'm fairly sure I need to do this because I get my intake manifold lined with oil and I think it's enough to have hindered or stopped the VRIS system in the past.

That delightful kick in the back at 5000RPM, until just recently, wasn't always discernible at operating temperature and the torque before I put in a KL engine was sometimes but not always a bit poor at low RPM.

Hi All,
I know this post hasn't been added to in a few years but thought I would add my thoughts.

With the KF/KL there is a air feed from the inlet pipe (just in front of the throttle) and this is "metered" air as it is taken after the VAF or MAF.
This air is pulled into the engine through the top of both cam covers when the PCV valve is open due to vaccum in the inlet manifold thereby pulling the air through the engine and removing the blow by fumes and burning them in the engine.
As your engine wears the amount of fumes becomes much higher causing the PCV to clog and the inlet manifold to get very dirty inside.
The installation of the oil catch can must be part of this metered air feed system otherwise the ECU maps are incorrect.
I recommend the following set up which I did have on my KLZE before I rebuilt it and it did remove oil from the breather system very well.

1 - PCV Valve pipe to Oil catch can.
2 - Pipe from Oil catch can to inlet manifold where the PCV pipe went before.
3 - No breather on the catch can.

This set up ensures clear air back into the inlet manifold and if your engine is in poor condition check the can regularly to ensure it doesn't over flow .

If you go with the other system recommend the following.

1 - block off the air feed from the inlet manifold pipe.
2 - Take a pipe from the top of both cam covers and put them into a oil catch can with a air filter on top of the can.
3 - Remove the PCV and block the hole.
4 - Remove the PCV pipe and block the connection in the inlet manifold.

This system relies on pressure in the engine to push the air and fumes out, where as the first system pulls the fumes out.
This is a little different from Pauls system in that Paul still has the PCV system in play therefore unmetered air goes into the engine via the catch can and PCV which could result in a lean mix.
No oil will get in the can either.

Good Luck
Craig

Thanks for the info. On the later models there is no pipe coming from the front of the rocker cover. Could you post some photos up of your 2.5 setup please as I'm doing this at the moment. Thanks

Hi Paul,
I didn't refit the oil catch can system after I rebuilt the engine.(Didn't need it)

Real easy to do.
You will need a catch can.
Now catch cans often do not have any separation plate or filter element etc in them to ensure the gases have the oil removed from them. I have fitted a separation plate and filter in both cans I have brought.

As you can see in the photo there is a separation plate that runs from the top to the bottom and I have drilled lots of holes in the plate from about half way down.
The plate separates the inlet and outlet at the top otherwise the gases could be sucked straight out the outlet.
I have then used filter element I sourced from compressed air equipment supplier that they use on compressors etc. You could use steel wool pads also.
Buy a can with a drain on the bottom. Makes it easy to empty.
Ensure the inlet and outlet ports/connections are the same size as the PVC valve.
Most catch cans come with different sizes of connector or you can buy the right ones if not.
Buy some hose the right size and the right spec. (Can handle the gases and doesn't collapse when bent)
The can does not need an air filter.
Install
1/ Mount the catch can. (I had my one down by the radiator overflow bottle just in front of the gearbox.)
2/Remove the hose that runs from the PCV Valve to the Inlet manifold.


3/ Fit the first hose from the PVC Valve to the inlet on the can.
4/ Fit the second hose from the outlet of the can to the inlet manifold.
Done.
If your engines turbo, has hard use, or is showing its age expect to have to empty the can from time to time.
Where I had my can allowed me to empty it when I did a oil change. (From under the car.)

Paul also noted that there was no breather pipe on the front cam cover for his engine.
This was possibly removed by Mazda on later engines as possibly interfering with air flow.
It meant they had one inlet breather on the rear cam cover and the PCV valve on the front cover, thereby having air flow across the internals of the engine and out through the PCV.

There are other ways of having your breather system that maybe better suited to high pressure turbo set ups where there is much more blow by and the inlet is modded and you are running a aftermarket ECU.

Thanks