ok people with oil catch tanks

what tank do you have?
where have you fitted it?
do you have a breather or do you vent it into the intake

 

Bump. Noone?

 

I run an air oil separator, so its maintenance free - fits onto oil filler pipe in place of normal cap.

http://i5.photobucket.com/albums/y18...ps1a9a369c.jpg

And so far appears to be doing the job

 

Obp one fitted to passenger side suspension turret.
Vta and needs emptying monthlyish.
The amount of moisture and crap it collects I wouldnt want it going back in intake.

 

OBP can fitted to N/S chassis rail, VTA and RTS

 

What exactly does that do ??

 

The job of a baffled catch can but is closed circuit, so oil returns to sump via oil filler neck, air redirects to inlet. Pcv is redirected to it with the inlet take off blocked

 

Puts all the crap back in the car..

 

what crap tho?

The crap you see in your catch can is due to temp difference and being vta allowing moisture to build which gives the crap you pour out of it. This is closed circuit so moisture cant get in

 

A closed system, if there is such a thing, is likely to do your engine internals no good at all.
Have a read here http://www.andyforrestperformance.co.uk/26001.html

 

ive read all about it, wasnt just bought on a whim. PCV valve remains - so its just an extension of the original OE breather system that separates the oil from the air

 

So it's not a closed system then? And if not atmospheric moisture can and will get in.

 

where does moisture get in in the original OE breather system?

 

You say you've 'read all about it' and yet you've missed a key feature of standard crankcase ventilation
Quote from Andy Forrest...
"The Subaru system has two main phases depending on manifold pressure/vacuum.
Under manifold vacuum conditions (probably 99% of the engines life) there is a non return valve under the throttle body, which allows the 'blow by' vapours to be drawn into the manifold. The vapours are replaced from the vents on the cam covers, supplied from the inlet duct. This provides the circulation of air through the engine, prevents condensation, oil contamination and internal corrosion."

 

yes i read that.

maybe i stated wrong in saying its 'closed loop' what im saying is that it doesn't VTA and that the oil does not catch (in the can) and as such does not get contaminated with moisture that mixes forms the milky substance everybody see's in their catch can.

 

But there will be fresh air drawn into the crankcase by virtue of 'the vents on the cam covers, supplied from the inlet duct.' Therefore you can't help but have some moisture content. The fact that you aren't seeing any mayonnaise is probably more likely to be because your engine is run at proper operating temperatures for long enough to evaporate any contaminating water vapour in the oil.

 

It dose seem a tad risky putting it back into the engine. However any moisture will quickly eveporate and get sucked through the intake and out the exhaust. Quite a tricky choice

 

whats tricky about the choice of putting crap in your engine or not???


id rather not

 

Important question. Where dose the air get into the cam covers and other vented areas ect?

this picture seems to agree with andy forsits statements

 

but the point being you are running a standard power wrx, personally i wouldnt bother with a catch can you will see no benefit just money wasted.

 

well there not exactly expensive so im not to worried

why is there no benefit? i want my intake to be nice and clean. the idle valve gets clogged with crappy oil?

im thinking the best setup would be:

vents are all connected to catch can, catch can then T off.

one side goes to PCV and allows air to be drawn into the intake off boost
another side gose to a one way valve to stop the vacuum drawing air in and then to a vent

maybe its an idea to bleed off a tiny amount off boost into the intake to keep it pressurized and open the one way valve
more research tells me that piston blow by pressurizes the inside off the engine so you dont need to pressureise it. it wount be long till you come off throttle anyway and the intake sucks it all up anyway

it seems to be a good idea to install a 1 way valve though
if you VTA then most off the time thats actualy being an intake. not a vent! this is potentaly draging moist air through the system

 

ok well there is a slight benefit obviously,but i meant more there is not an issue on a standard wrx with the idll valve etc getting dirty and even if it does its a simple fix to clean.

all you will be doing is creating a can to empty with no real benefit to the car. spend the money on something else, a good service would be more beneficial to the car.
a catch can is really not needed on a standard power wrx at all.

 

ok? whats the benafit to high powered cars?

 

mainly keeps the octane rating up, which is good on high powered cars to avoid knock, obviously on a standard car its not so important as its not running at the limit.

i fitted one when i fitted my fmic to avoid getting the new intercooler and pipe work coated in residue,obviously your car has been running for a few years so the oil residue is already there so unless your going to clean it all out then fit the can its pretty pointless and as its running ok now the residue is doing no harm anyway so why fit a can???

 

i will be remapping the car at some point though
and i plan on changing the top mount and pipework yeah

your not massivly convincing me to not get one. there only like 25 quid on ebay

 

and the £25 ones are crap, you need a baffled one really and also a fair bit of decent piping and clips.
a proper 3 port baffled set up with pipework is more like £100 plus.

im not trying to convince you, just posting an opinion that its a waste of money on a standard wrx.

it will do no harm and possibly even have a tiny benefit, but the cost involved and the hassle to empty it assuming you are not returning to sump is not worth it.

 

you can add baffles easily though and iv got to buy pipe work anyway
if it saves me having to clean the car out every year i think its worth it
thanks for your help though

 

Am I right in thinking what this does is redirect oil breathers into the sump,rather than into the air intake pipe? Meaning a cleaner intake pipe

 

Kind of. What the Air/Oil seperator does is route the breathers to the oil filler neck. The seperator uses the vacuum from the inlet to pull the fumes through but leaves the oil residue in the filler neck. So effectively yes, it does return to the sump via the filler neck.
Does that make sense?
Paul.

 

On a 2.5 that is oil thirsty and is used hard that regulary has the oil dropped out of it.
So a more track focused car, then there is a case for running a return to sump feed from the catch can.

On most set ups I would go for VTA. As it does collect crap