Unique Baffling Controls Crankcase Pressure.The larger the AOS, the more power you can safely make without having to worry about the AOS overfilling. With a 4" OD and 5.75" height, the AOS has an approximate 1 liter of holding capacity. Additionally, this reduces overall system pressure. By giving each engine port its own entrance to the AOS we have allowed for more effective and faster excavation of crankcase pressure. Each engine vent port receives its own connection to the AOS. The Subaru EJ engine has 3 ports that vent crank pressure: one on each cylinder head and another on the top of the block. There are NO plastic fittings that require thread tape to seal. The side of the AOS features 3 port billet hose barbs. Also available in World Rally Blue (automotive paint). Aluminum Body is powder coated in Red, Black, Gold, Dark Silver.Every o-ring in our AOS is formed from Viton which offers superior temperature and chemical resistance. On the bottom, a thick Viton o-ring seals the can. A total of 9 mounting holes enable the breathing port a full 180° of rotation. The slower velocity leads to greater oil separation from the pressure stream. By increasing the overall volume of the breather opening on the top of the AOS, we have drastically decreased the exit velocity of the crankcase vent (CCV) stream.
As air and particles of oil enter into the AOS, the largest particles of oil will collect on the inner surface of the can and drain to the bottom, but the smallest particles will remain suspended in the pressurized stream.Īs the air makes its way through the multi-stage baffle system, gravity pulls oil from the air. Notice the dual breather port? At first glance you might think this is excessive, however, our reasoning is grounded in simple physics.