Catch Cans – What’s inside yours and how often do you empty it?

[A_J_T]

Soo generally speaking im pretty happy with my catch can setup and how its funtioning.

I've emptied my crank case breather can twice in the last 3000-4000 or so km's as its just come up maybe 1/3rd of the way up the sight pipe on the side of the catch can. I've emptied the rocker cover can once.

Catch can setup is like this.

And what comes out is a mostly watery oily gunk, the crank case can is more oily "the one on the right".

Soo anyway, im fairly happy with whats coming out but am interested to see what others get and if its similar?

Edited October 15, 2015 by A_J_T

[Guest]

My crankcase and head breathers are teed to atmo pump bottle. Collects zero oil.

[A_J_T]

Yea, its mostly water i think. Possibly having a closed loop breather provokes moister and condensation build up. still not convinced its ideal

[lachlan]

u get that much in 2000 k ? is it ****ed ?

u need some more baffles ( or steel wool) in the line from the crank case so the oil stays there . failing that just run a drain from the catch can back to the sump . metal kidney plate would prolly help too

the oil is supposed to get hot enough to burn off the water and other impurities .

[Guest]

Water is condensation i found aluminum catch can shocking for it.

[pedro]

Get bugger all out of mine..

Check it every oil change and never more than a cup full..

Mixture of water and a little bit of oil looking like a bad mayo..

[Guest]

Take it on the track then see how much you get. Absolute nightmare, beginning to think maybe sr20 is the way to go.

[boon]

 ballsrburning said:

Take it on the track then see how much you get. Absolute nightmare, beginning to think maybe sr20 is the way to go.

Dry sump....

[pedro]

 ballsrburning said:

Take it on the track then see how much you get. Absolute nightmare, beginning to think maybe sr20 is the way to go.

No extra in catch can after track days...

[Munkvy]

I have done 3 track days and 2 sprints on my catch can setup and had less than a cup full of oil in it. However I run one large can that is teed off both rocker cover breathers and the crank breather all into the one big can which is mounted on the firewall, higher than the engine, idea being to make sure as much oil as possible runs back into the engine, rather than pooling in can.

[A_J_T]

on the left is the rocker cover content "only emptied once since last oil change" maybe 4000 odd kms

on the right is the crank case which i emptied out maybe 1000kms ago, not that much.

Also its mostly water, below pic shows oil and water separation better.

the main question is, is all that water actually coming from inside the rocker covers and what not or am i building up condensation in the cans.

The setup im running is purposely like it so it creates vacuum and draws all the fumes and what blow by there is out of the breathing areas during boost “exactly how Subaru designed it from the factory” only difference is it vents the air and not all the filth back to intake. Checked the intake and mani and it’s all dry as a bone and clean.

Car is fine, engine is fine im happy with the results not stressed just interested to know what others are getting with diferent setups and possibly looking at having a play around with different ideas.

[A_J_T]

 ballsrburning said:

Take it on the track then see how much you get. Absolute nightmare, beginning to think maybe sr20 is the way to go.

You get alot?

[slystiguy]

I am a little embarassed to say I haven't actually plumbed mine up yet haha I should really do that...

I've noticed drivers side tends to be a bit worse for build up

[Minaj]

On E85 depending how hard I drive it would fill up within couple of days.

[Guest]

 A_J_T said:

You get alot?

Yep on e85 it's bloody ridiculous, I'm now redesigning it all, to try and improve it. At Manfield I was doing 5 laps then having to slow down as it was filling and going into the intake.

[Optical]

 ballsrburning said:

Yep on e85 it's bloody ridiculous, I'm now redesigning it all, to try and improve it. At Manfield I was doing 5 laps then having to slow down as it was filling and going into the intake.

You will definitely need a recirculating breather setup for track work. Dual containment areas seems to work pretty well for most of us

[Guest]

 Optical said:

You will definitely need a recirculating breather setup for track work. Dual containment areas seems to work pretty well for most of us

Since Manfield we did plumb up a dual containment system, it was better but not perfect, got another couple of designs to try, but dual containment is going to continue. I am coming around to installing some sort of tap on the head breathers to block one off on certain tracks would prefer not to do this though.