Engine (03.00)

Engine (03.00)

Emission Control (03.08)

System Description

To avoid environmental pollution from the crankcase gases (blow-by), the crankcase (engine) is ventilated into the intake system. Any noxious fumes in the crankcase gases are then burned in the normal combustion process.

The system consists of a part load and full load breather system which ensures sufficient engine venting under all running conditions.

Crankcase gases escape through channels in the block walls where they are fed into oil separators to minimise the oil pullover. From the separators, pipe work channels the vent gases to the intake manifold at part load or intake system at full load.

Under part load conditions the system is controlled by the PCV valve which regulates a constant flow of vent gases (engine blowby varies across the range of part load sites). The PCV valve flow is balanced by the 'make up air' pipes to the cam covers. The pressure difference across the ends of these pipes (i.e. across the throttle valve) activates the PCV valve.

At full load, the system vents through a 1-way valve to the RH inlet system (pre-throttle) only.

The diameter of the pipes in the system is critical in the control of the Full and Part load operating conditions.Vacuum Pipework Layout