Stage X Oil Sump Pan Baffle Plate

Oil control is a particular problem for the Subaru flat-four boxer engine because of its high crankcase pressure and horizontal layout.

When cornering at speed, oil can work its way out of the sump pan and across to the cylinder head castings, leaving less oil around the oil pick-up pipe.

The pick-up pipe draws oil from the sump and distributes it to the engine's oil galleries, keeping moving components lubricated and cool. If the pipe cannot reach oil, parts of the engine are starved, temperatures rise, metals expand and components eventually fail.

A baffle plate acts as a "lid" on the container holding the oil, so that when the car's momentum throws the oil to one side, it stays in its designated area.

Rubber flaps ("diverters") are fitted across the base of the plate. They open one way only, letting oil drain into the sump. In hard cornering, oil finds it much harder to flow out because its usual escape routes are closed or removed. This makes a sump baffle plate well suited to fast road driving, track days, rallying and sprint events.

For further protection, a Stage X baffled sump can be used together with the baffle plate, giving the best oil control short of a dry sump system.