Looking at getting the above for my 1.0L ecoboost 100PS, but on eBay there's a fair few different sizes, which size would I need to get or does if not matter?

anyone?

Its got to fit the breather outlet - it can fit straight on the outlet or via a short length of hose normally with a connector tube, you could measure the breather (outlet or hose) on your own cat to see what diameter filter you need

There are things you should know before considering fitting an oil breather filter -

Harmful gasses like carbon monoxide can come out of the breather, you must be careful this does not make its way into the passenger cabin (eg via the vents, or other ways) you may be better fitting an oil breather catchtank and feed it back into the inlet (where it already goes) rather than releasing the breather gasses (and oil mist/ droplets) into the atmosphere, or the crancase breather outlet treated like a second exhaust, going right under the car/ away from the passenger cabin

You must know what you are doing when fitting these things, the air inlet must be blocked but the breather left open - some racing induction kits do not have breather air inlets

Even racing cars may require oil breather catchtanks to pass scrutineering, (in order to be allowed to race) some tracks will not allow cars without catchtanks on track (even for a track day or RWUB drag race)

A breather filter can get really dirty/ oily, it can dirty the engine bay

Apart from the poisonous fumes, you can get the smell of burnt oil coming into the car, or buystanders/ pedestrians (including your fanily/ mates etc) can get the smell - it can smell like an old car with a worn engine that is burning oil

My best advice is to forget about the oil breather filter and choose a nice metal oil breather catchtank instead and fit it between the oil breater outlet and engine air intake

My question is why fit one in the first place?

My question is why fit one in the first place?

Why would you need one tho?

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They are used to vent the crankcase due to blow-by, if you have a highly tuned race engine you would expect more blow-by and a high crankcase pressure and high levels of oils fumes.

For old duffers like me who remember pre-emission days, engines had a road draft tube where all the muck from the engine would drip onto the road and the fumes into the atmosphere.

Now the fumes are burnt in the engine and all the liquid muck drops back into the engine. Not much point fitting one to a modern engine as you bypass the PCV system and possibly upset the engine management system.

As FOCA said above a catch tank is a better proposition but again you already have a system to catch the liquid muck.

Ok i get you, where as now a days its the little black filter inside the air filter box right? That gets oily some times

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Correct!

Cheers, do you have to clean it tho?

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Generally no, my last Mondeo was a bit wet with oil after 80,000 miles but it was not blocked.

Sweet cheers :)

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