Air filter replacement - S2
Discussion
Hi, just bought myself a nice new Pipercross air filter to fit to my S2. I was looking through some old streams on Pistonheads heads and found the statement below from back in 2010. Is this still a good idea, and where do I get the parts from as all the links seem to be old and out of date?
“If you buy a new filter, dont go poking a hole in it to fit a manky pipe fitting pumping oily mist into your intake ahead of your AFM's rolleyes remove the pipe from the oil filler cap altogether and fit a small filter to the oil breather/filler cap instead, leaving your new and expensive new filter intact”
Any pictures of this as a completed job would be great.
Cheers
“If you buy a new filter, dont go poking a hole in it to fit a manky pipe fitting pumping oily mist into your intake ahead of your AFM's rolleyes remove the pipe from the oil filler cap altogether and fit a small filter to the oil breather/filler cap instead, leaving your new and expensive new filter intact”
Any pictures of this as a completed job would be great.
Cheers
Fez887 said:
..... fit a small filter to the oil breather/filler cap instead, leaving your new and expensive new filter intact. Any pictures of this as a completed job would be great.
I fitted a new Pipercross air filter a few months back, and an inexpensive breather filter. Around a fiver on Ebay and a five minute job to fit.
Have a look here
www.ebay.co.uk/itm/Universal-AIR-BREATHER-FILTER-R...
They come in different colours and sizes, 13mm is the correct fit and the hose clamp comes with it.
www.ebay.co.uk/itm/Universal-AIR-BREATHER-FILTER-R...
They come in different colours and sizes, 13mm is the correct fit and the hose clamp comes with it.
You won't be the first to do it, but it's not a good idea to use those small filters as a breather outlet. They aren't designed for that, and they don't work at all well.
They're designed for the inlet filter of a PCV system, filtering fresh air as it is drawn into the crank case.
The air coming out of the breather is far from clean and can hold a lot of oil mist, which is caught by these filters and eventually clogs them.
If you want to get rid of the recirculating breather system, the better way to do it is to take an oil-proof hose to a catch tank/separator with a vented outlet. This could be as simple as an empty beer tin cable-tied to a chassis upright.
They're designed for the inlet filter of a PCV system, filtering fresh air as it is drawn into the crank case.
The air coming out of the breather is far from clean and can hold a lot of oil mist, which is caught by these filters and eventually clogs them.
If you want to get rid of the recirculating breather system, the better way to do it is to take an oil-proof hose to a catch tank/separator with a vented outlet. This could be as simple as an empty beer tin cable-tied to a chassis upright.
For a standard engine in normal use, that's a reasonable option. Better would be to set up a PCV system so that the dirty air bypasses the throttle and air flow meter, but that's only practical if the intake manifold has the necessary connections.
For a high performance engine or one driven hard, a catch tank breather system enables better performance although it is worse for the environment.
For a high performance engine or one driven hard, a catch tank breather system enables better performance although it is worse for the environment.
GreenV8S said:
If you fit an air filter to the breather outlet and it becomes blocked (as it might well) then the crank case can pressurise under load, leading to seals failing.
Leave the hose clip a little loose, it'll just blow it off if it blocks 
From what I read on this Forum this is quite a popular mod, not aware of anyone having had troubles to date ....
I do see it from time to time, usually done by people who don't understand the difference between a PCV system and open breather system. You might well get away with it on a system that has very little blow-by and doesn't blow much oil out, but by the same token the original system dumping breather gases into the filter housing would have worked fine in those situations.
Bottom line for me is that a breather system that passes the breather gases through a paper element is asking for trouble, even if you don't always get it.
Bottom line for me is that a breather system that passes the breather gases through a paper element is asking for trouble, even if you don't always get it.
Ok so this debate is probably making me nervous enough to just put it back as original, this way I know it shouldn’t cause any long term issues. To be honest the only reason many people seem to make this change, is to avoid cutting a hole in the filter; but is that really such a bad thing?
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