Oil Catch Cans

[monsterenergy]

Thanks to Don for showing me some sites and giving me some ideas for modding!

Right - Oil Catch Cans... I fancy one because they seem like a good idea technically - and it's something else to look at in the engine bay!

Anyone recommend one, or advise against one? How easy are they to install?

I see Perrin do a silicone one available in red for £120 from JW Racing. Anyone think silicone would be as good as aluminium or alloy? I fancy red to match my manifold, K&N Typhoon and Perrin strut brace.

Otherwise there's a Cusco one from japanparts for £66 plus shipping etc.

Or Just-Subaru's one for about £65

Any other opinions much appreciated - thanks!

Edited April 30, 2012 by monsterenergy

[BalliSTIc]

Was looking into this myself... lots of controversy out there...

Cans seem to be OK if it's just for venting the heads... crank case seems to be a bit more of an issue. Sorry if the following is a teaching-granny-to-suck-eggs job but hopefully it's useful:

When cruising (ie manifold under vaccuum/ not boosting) there's a valve (PCV system - plenty info on google, not just scoobys) under the throttle body that sucks the gases out of the crank case. Under boost, the gases are sucked into the turbo inlet... in both cases that means the engine ingesting a (hopefully but no necessarily) small amount of oily air - clearly this aint great for knock resistance!

However, trying to vent the crank case is useful as it improves piston ring seal assuming sufficient suction/ vaccuum can be acheived... clearly a catch can is kinda passive so this ain't gonna work for the crank case. Better than nothing re oil catching perhaps, but far from perfect.

Air-Oil separators seem to be popular, especially those than plump onto the oil filler cap (Pro-R/ Tomioka, Prova, Grimmspeed etc) - they have a classy, stock look to them, but again they don't fully solve the crank venting issue. Crawford Performance's one seems well engineered but it's not really any better by the sounds of things.

What does work? Dry sump anyone?

Bottom line - catch can fine for heads... less so for crank case... and as ever, better solutions aint cheap!

[monsterenergy]

Ok - after all that I've gone for the Pro-R/Tamioka Air Oil Separator - I didn't even know Pro-R did these, so after looking at the design and also checking install instructions - I decided that was the one for me. Thanks for the advice!

Pro-R Tamioka AOS

An Air/Oil (AOS) Separator has one job, remove the oil from the engine ventilation system so the oil does not get sent through the intake system. The TR AOS has a unique design that allows you to maintain your PCV Valve while separating the oil out of the crankcase and head ventilation air!

Removing oil out of your intake system will result in a more efficient engine. An Air Oil Separator takes the place of an oil catch can or tank, resulting in you not having to empty your oil catch can. As well as being very subtle and not noticeable.

Another benefit to this unique design, is the compact and clean look. Making this ideal for someone who wants to keep it looking stock under the hood.

Edited May 1, 2012 by monsterenergy

[monsterenergy]

Right - I'm stuck! PLEASE HELP! lol

The installation diagrams that came with the Tamioka AOS are different from MY08 STi and I guess are for older engine.

Same as on link here Tamioka Install Link

I've looked online and have found installation instructions for a Prova AOS - and they seem to have really simplified the installation - and I can see how it might work:

Prova Install Link

Don - if you read this, have you a foto of how your Tamioka one is installed please? From the foto I've included on your engine below - I'm interested to know what's going on "round the back".

Or do you think I could follow the Prova instructions?

Much appreciated!

edit to add some fotos:

1.

2.

3.

The hose I'm pointing at in #1 foto attaches to the turbo inlet hose with the fitting marked with the white 'x' shown in foto #2.

Should I unplug this hose from the plastic fitting on the turbo hose?

Then use a rubber cap on the plastic fitting.

Then use the #1 hose to come up and T into the breather hose that I will run to the AOS?

Foto of Don's engine from Hatch Mods thread.

Edited May 5, 2012 by monsterenergy