Emission Control Systems: Description and Operation

Engine Emission Control

COMPONENT LOCATION









INTRODUCTION
The engine emission control system reduces the level of hydrocarbon emissions released to atmosphere from the engine. The engine emission control system consists of a PCV (positive crankcase ventilation) system with part and full load breathers. Piston blow-by gases are drawn through the breathers into the engine air intake and added to the air charge. The resultant depression in the engine sump, front covers and cylinder head covers reduces the load on the joint seals in those areas.

PART LOAD BREATHER









The part load breather consists of an oil separator, two PCV (positive crankcase ventilation) valves and a flexible hose. The oil separator and the PCV (positive crankcase ventilation) valves are installed in the top of the RH (right-hand) cylinder head cover. The flexible hose connects the RH (right-hand) cylinder head cover to the inlet of the intake manifold.
The oil separator is installed in a channel in the top of the cylinder head cover. A baffle plate, which incorporates a gas inlet and an oil drain, is installed over the channel. The two PCV (positive crankcase ventilation) valves are installed on the outside of the cylinder head cover and connected in parallel in the gas outlet from the channel to the flexible hose. The PCV (positive crankcase ventilation) valves prevent reverse flow into the cylinder head cover when there is minimal depression in the intake manifold.

FULL LOAD BREATHER









The full load breather consists of an oil separator, a two-way valve and a flexible hose. The oil separator and the two-way valve are installed in the top of the LH (left-hand) cylinder head cover. The flexible hose connects the LH (left-hand) cylinder head cover to the LH (left-hand) air duct of the intake air distribution and filtering system.
The oil separator is installed in a channel in the top of the cylinder head cover. A baffle plate, which incorporates a gas inlet and an oil drain, is installed over the channel. The two-way valve is installed in the gas outlet from the channel. The two-way valve prevents reverse flow into the cylinder head cover when there is minimal depression in the air duct.