LE Car
The oil-carrying fumes from the rocker cover are drawn into the oil separator. The oil is divided from the vapors and returned to the crankcase. From the oil separator, the vapors are drawn into the intake system for reburning. The .059" (1.5 mm) restricted orifice is located between the rocker arm cover and the intake manifold. It controls the amount of crankcase vapor reaching the intake manifold at any one time.
When engine speeds and loads are low, vacuum draws crankcase vapors through the hose to the intake manifold. At higher loads, both hoses are used, and at full throttle, all ventilation is provided through the hose to the air cleaner. The evaporative emissions canister is also purged through the same hoses used for the crankcase ventilation system.