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Description & Operation

A closed type system is used. The system consists of a head cover baffle plate, a regulating orifice, hose connections, and hoses. Blow-by gas suction is controlled by the regulating orifice.

Under normal operating conditions, blow-by gases are drawn from the valve cover into the intake manifold to be burned by the engine. When engine is running at its maximum speed, intake manifold pressure is too low to handle all the blow-by gas.

Some of the gas will be drawn into the air cleaner, through the rear end of the head cover. The regulating orifice, mounted on the intake manifold, regulates blow-by gas flow in response to variations of intake manifold vacuum.

Fig 1: Crankcase Ventilation System
G37821