Print

[scsja]

was looking on ebay and came across this:

http://www.ebay.co.uk/itm/Oil-Mini-Breather-Air-Filter-Fuel-Crankcase-Engine-Car-Bike-Select-Size-/330803496881?var=&hash=item4d056cc7b1

On the Smart Forfour where would this go?

[mozilla]

On top right of the Brab engine is the EGR recirc hose that connects to air intake near the 'B' stub. This little filter connects on the engine side and you would jave to block of the connection to the intake side of that hose. Its good mod for the car, no recirculation of warm oily air

Not sure if its a MOT legal mod

[scsja]

Ok just to confirm i understand this

the pipe from the engine to the air box has a thinner pipe coming of this to the back of the engine (my car forfour 1.5 petrol)

Now can i remove that pipe? where the thinner pipe went to the back of the engine that filter would go there?

What size would i need Diameter: 9 12 15 or 25mm

Thanks.

[mozilla]

Yes its that small pipe.
Not sure about size, you would have to go measure it

[Alex]

Hi, our cars are normally aspirated, I don't know if that hose is designed to vent atmospherically! On our cars, the vacuum in the intake sucks in those oil vapors. You would be better off with an oil catch can, because that is plumbed in line, and filters out the oil and just lets the fumes through, so it is still subjected to the vacuum of the intake manifold.

Although I suspect you want such a thing because your new intake system has no place to plumb in your breather hose.

[scsja]

Although I suspect you want such a thing because your new intake system has no place to plumb in your breather hose.

Yes that's correct. My idea is to put the breather filter in place of that pipe remove the original pipe altogether and place the air filter straight to the engine.

[Alex]

Then maybe somebody with more knowledge can tell you if it's OK to use a breather filter like that.

[CrazyG]

Alex is correct. The hose is not supposed to vent to the atmosphere.....as 'by law' the
oily fumes have to be re-circulated to be burnt, as part of the combustion process.
An oil catch tank is a good idea....for a race car, but even that vents to the atmosphere, so
once again it is a possible failure if 'found'.

However...before everyone posts up that they have seen others do it or even changed
theirs etc etc etc...I must stress that 'we' (the Admin Team) have a duty to inform or advise
anyone reading the forum of the possible legal/illegal nature of any mod put forward or shown
on here.
YES, we all know what you can/should and cannot/should not do.
The onus is on the individual to do as they feel fit, and if you want to fit this, then so be it.
After all, most MoT testers do not 'prowl' around your engine that deeply, BUT if he smells
hot oily fumes or vapour, then ther is a possibility that he might just have a closer look, and
if he finds it he will fail the car.
On the other hand, if you do find a way to recycle the vapours back into the engine when it
comes to 'that time of year'......

[Alex]

Well the filter filters out the oil, and retains it in some degree, although the vapors still go through it if they don't have time to condense, plus after a while it might end up dripping oil on your hot manifold, and even be a fire hazard.

The catch cans I've seen are like inline fuel filters, they retain the oil (they have a filter medium inside that filters out the droplets and gives the vapor time to condense) and only allow the air to pass into the intake.

Reading more about the PCV valve it would seem that it may be fine venting atmospherically, it only opens when there is Positive Crankcase pressure (positive crankcase pressure valve) but if it were me, I would try and find a way to retain the original setup.

[mozilla]

If the air intake causes a vacuum and causes a sucking effect of the crank case vapours , which are then burnt/deposited on the intake piping and throttle body this effect would be lost with the AEM filter. Its possible the stock recirc set up has a cleaning effect on the crankcase which would otherwise sludge up the crankshaft  My crazy theory!

[scsja]

The breather pipe from the main air intake pipe does that have a filter in it or is it just a hollow pipe?

[mozilla]

I havent checked but I'd guess hollow. As its sucks air which has already been filtered