Crankcase Ventilation System Description

Crankcase Ventilation System Description
A crankcase ventilation system is used in order to provide a more complete scavenging of crankcase vapors. The air cleaner supplies fresh air through a filter to the crankcase. The crankcase mixes the fresh air with blow-by gases. This mixture then passes through a crankcase depression regulator valve into the intake manifold.
The primary control is through the crankcase depression regulator valve (1), which meters the flow at a rate depending on the crankcase pressure.
In order to maintain an idle quality, the crankcase depression regulator valve restricts the flow when the crankcase pressure is high. If abnormal operating conditions arise, the system is designed in order to allow the excessive amounts of blow-by gases to back flow through the crankcase vent tube into the air cleaner in order to be consumed by normal combustion.