on a bailey oil breather/sperator does it make much of a change to the running , i mean what do they do are they a good but and can you get them cheaper ?!

 

Shouldn't affect running at all, they are very overpriced imo, look on www.ratsport.co.uk for a much less expensive one, or make your own, the baileys is not even a good design imo.
They can be made for around £10-£20 if you have basic facilities.
tabetha