The Subaru boxer platform can have issues with oil surging in the heads. It can be related to the level of performance, driving style, track conditions and so on. This burden is often overwhelming to the PCV's A/O separator or Catch Can system causing them to fill. Filling an A/O separator or catch can causes oil levels to drop increasing the potential for oil starvation. Another condition is if a catch can fills, and overflows onto a hot engine and/or exhaust system creating a fire potential, which has been known to happen.
The Oil Control Valve prevents oil flow out of the valve cover ports based on the lateral forces placed on the car. This design has been successfully used in aerobatic aircraft for years and they have adapted the design to be suitable for lateral loading vs inverted flight (which really shouldn't happen in cars). Under straight line acceleration, braking and moderate cornering the PCV vents work just as they normally would; letting blow-by gasses vent from all ports. Under severe lateral loads the port from the surging head (facing the outside of a corner) is closed, not allowing oil to pass into the A/O or catch can setup. The balance ports and remaining head and crankcase ports still operate as normal. This has no negative effect on the engine or engine performance, while assuring blow-by gasses ONLY are permitted through the PCVs ports.
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Items that are covered under the RallySport Guarantee offer a 30 day no questions asked return policy.
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The RallySport Guarantee does not apply to products that have been modified, damaged, misused or abused. All returns require an RMA (Return Merchandise Authorization) Number, and freight charges are strictly non-refundable. For more information regarding our freight refund policy, please refer to our return policy page found HERE.
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QUESTIONS & ANSWERS
Q: Few questions Subaru Source 3 years agoAnswer
Where is this mounted and what size AN fittings?
A: This can be mounted above the pitch stop mount on the firewall with the supplied bracket or anywhere in the engine bay as long as it is connected to the valve cover breathers properly. The inlets are 3/8NPT and the outlet is -12AN.
Zach G. 3 years ago