G'day gents,

Just a few questions regarding the crankcase breather pipe... are they threaded into the block?? Mine seems to be quite a large pipe just vented to the ground and leaks on the extractors which I hate, If some one can post some pics of there catch can set ups and hose sizes that would be great! cheers guys.

A15 uses a Breather Pipe that sticks straight out. Some versions (vanette?) come out then curve up.




The pipe is a press fit into the block. Put vice-grips on it and tap the vice-grips until the pipe comes out.

Tap the new pipe into place. It is a taper fit, and needs no sealant.

Get a hose from the Rocker cover vent and another from the pipe out of the crank breather and make up on like thus for less than $10 like I did lol.





Then placed it here



Now I feel like IM turning into Jmac (it's a compliment John), technically you need to have almost twice as,much air filtration out as you have in to not build back pressure into the sump or rocker cover areas. I remember reading that somewhere so I run 2 small filters for my one line in (I don't have a crank breather).

It's also advised to run a pcv so condensation and air doesn't reenter the breathers before the catch can.

It should be noted that the catch cans should recirculate the air back into the inlet tract as per factory.

Also if your crank is pudding out heaps,of oil vapour you might want to investigate that further

Thanks guys really appreciate it, like you mentioned dd its got the curved pipe but turned to face downwards... I have no provisions to run back into the inlet manifold so need to run both into catch can im guessing. Would it be ok to just run the one filter ontop of catch can for both rocker cover and crankcase going into it?? Also do i need to take the carbies/inlet manifold off to get to it or can get it done from underneath??
Thanks for all the help guys!!

None of the breather pipes run back to the manifold. They are all connected via rubber hose.

Unless you are racing, just connect the stock PCV system:
* Rubber hose from breather tube to PCV valve on the manifold.
* Rubber hose from rocker cover to shell of the air cleaner

It is by far the simplest way.

Thanks for the reply dd, as far as I can see there is no pcv system in place mate, Im running twin 40mm webbers with sock filters so no air cleaner shell.
It just has the rocker cover breather venting to atmosphere(just a braided hose facing away and down) and the curved breather pipe facing down venting all over my extractors LOL

The pcv is into the manifold from the crank breather in stick form is a breather going into the manifold dd.
I forgot a series as was 5 years ago I had one.

But yes one filter out of catch can fine, just try make the outlet pipe bigger.

Quite common for Webber and aftermarket early Su manifolds don't have provisions for pcvs

As far as the law's concerned your car isn't roadworthy with the crank case venting to atmosphere like that.

The crank case breather connects on the engine side of the throttle plates and draws air through from the inlet on the rocker cover. It's usually fitted with a non-return valve (specifically the PCV valve) to prevent back flow if there's a backfire. The inlet on the rocker cover is either fitted with a filter or connected to the air cleaner. This system helps keep your oil and crank case dry as well as reducing emissions.

You can probably drill and tap some threads to fit some hose barbs into the manifold (ideally one per runner since you have 4 throttle plates). You'd need to plumb that up to the crank case breather. The carbs then need to be retuned for the extra air bleed, particularly the idle circuit. I'd imagine something that fits 1/4" fuel line to each runner would be about right. If it's too big you might need to fit some kind of throttle in the vacuum line that leads to the crank case.

At the very least connect the crank case pipe to something to stop the oil dripping out.

Hope that's helpful.

Thanks guys appreciate all the help!
Cheers.

do as dave says & reconnect the stock PCV system. I have a cannon & weber DCOE on my A15 & the catch can sucked (want to buy it, really shiny & pretty sittin on my shelf...). Not sure what manifold you have but figure out a way to reconnect the return line from the PCV off the breather pipe to the manifole. My cannon had a plug on it I used to port it into that, your dual mani should have something similar.

The catch can just made a mess in the long run & its beter to vent back to the motor so the vapor can be buent again anyways.