Oil Catch Can installation?

[Davezj]

Just wondering if it is fine to vent the return pipe that comes out of the catch can to atmosphere or does it have to go into the pipe after the maf?

Also I dont supppose someone could elaborate on this perhaps with a pic/diagram? I cant get my head around how this part supposed to go together!

Dom has this slightly wrong as the PCV valve is attached to all cylinder inlets, not just the front 3 cylinders.
the PCV valve allows oil vapour to suckked into the engine only when the inlet manifold is under vacuum, e.g. at idle, at cruise, at low load on the engine.
it is perfectly acceptable to do this.
Is also acceptable to vent the crank case pressure and oil vapour directly through a filter into the engine bay, not through a catch can.
but it is more environmentally friendly and cleaner to burn the oil vapour in the engine via the PCV valve system and to collect the remaining oil vapour in a catch can and if an oil drain/return pipe is fitted then the condesnsed oil in the catch can will flow directly back to the sump so you do not loose any of it from the engine.
the pipe from the inlet pipework to the oil catch can, just aids in the collection of the oil vapour, as a small vacuum is created in the inlet pipe work and helps to suck the vapour into the catch can. but the crank case pressure is pushing the vapour into the catch can anyway, so venting the catch can with a filter if perfect OK as the oil vapour has been caught in the can anyway.

[Humpty's Revenge]

Putting an air filtered oil catch can will suck in un-metered air

[Davezj]

you maen through the PCV valve system through all the baffles in the rocker cover and the pipework and the condensation media in the catch can.
yes you could get some air in there, not much but it would be possible.
if that is an issue then you can fit a PCV valve (or any other one way valve) on the catch can so it only vents out.
or just connect the pipe to the inlet pipe work.

[swinks]

Oil catch can supposed to be fitted in-line into head breather pipe, not a pcv valve.

[swinks]

Dom has this slightly wrong as the PCV valve is attached to all cylinder inlets, not just the front 3 cylinders.

Yhmmm... pcv valve sits in-line between front head and intake plenum lower chamber. Can't see anything to do with rear head.
Correct statement should be that pcv valve regulates pressure between intake plenum (after throttle body) and cylinder heads (directly front head and partialy through a brearther pipe rear one).

[Davezj]

Yhmmm... pcv valve sits in-line between front head and intake plenum lower chamber. Can't see anything to do with rear head.
Correct statement should be that pcv valve regulates pressure between intake plenum (after throttle body) and cylinder heads (directly front head and partialy through a brearther pipe rear one).

i thought i would make this a little clearer as you expanation although correct was a little vauge and general.

my point in saying dom was slightly wrong in his assumption that the pcv valve only connected to the front 3 cylinders, is because the PCV valve connects into the tube that runs under the inlet manifold (which is part of the inlet manifold casting) and this tube is connected to all of the cylinder inlets, not just the front 3.

Yon can put it this way that blowby gasses (past piston rings) that pressurises cranck case and head area under the rocker cover on both front and back banks are disapated through the PCV valve system when the inlet manold is under vacuum and the rocker cover vent pipe to inlet pipework when the inlet manifold is under positive pressure.
the oil vapour is in the same area as the blowby gasses and gets carried along with them.

[babasvr4]

I built mine using 2" copper pipe, caps top and bottom and two 3/8 copper lengths on top, one in about 4 inches long and the return about 2 inches long. Used coarse s/s scourer to trap oily vapours
Some spare silicone to secure it to battery cowl and away we go!

[FLPGACITUA]

So, i know this is an old thread.. But, would it be a good idea to Tap into the hose that runs between the Front and Rear bank, Block the outlet that feeds into turbo inlet and have a filtered catch can for it to not pressurise and keep the air flow coming from the valve covers?

What about the PCV pipe that feeds into the manifold?
Would it be a good idea to have a second Solid catch can that simply taps into that Link? So, run a short as possible hose into a solid can catch-can that feeds back into the position it's meant to go?
OR, running the the PCV side into a Filter Catch can and Block the inlet? Or possibly just add a Filter to the inlet into the manifold side?
Am i just talking crap? I'll try to make a diagram.
Let's keep it simple. With diagrams if possible please