The term blow-by gas stands for the compressed gas and combustion gas which blow through cylinder-to-piston clearance, which contains a large amount of unburned gases such as CO and HC. The Positive Crankcase Ventilation (PCV) system is provided to prevent the blow-by gas from being emitted into the atmosphere.
The PCV system is a metered orifice type which supplied vacuum from the intake plenum through a vacuum hose to a metered orifice in the valve cover. The PCV system draws out blow-by gases at a controlled rate.
Operation
The Positive Crankcase Ventilation (PCV) system consists of a PCV hose and metered orifice mounted in the valve cover.
The PCV system is used to provide more complete scavenging of crankcase vapors.
The PCV system draws out blow-by gas through a the metered orifice, through the PCV hose and into the intake plenum and is consumed by normal combustion.
