Positive Crankcase Ventilation: Description and Operation

CRANKCASE VENTILATION SYSTEM

CCV System:

All these engines are equipped with a Closed Crankcase Ventilation (CCV) system.

The Closed Crankcase Ventilation (CCV) system performs the same function as a conventional PCV system, but does not use a vacuum controlled valve.

On these engines, a molded vacuum tube connects manifold vacuum to top of cylinder head (valve) cover at dash panel end. The vacuum fitting contains a fixed orifice of a calibrated size. It meters the amount of crankcase vapors drawn out of the engine.

A fresh air supply CCV tube (hose) from the air cleaner is connected to front of cylinder head cover.

When the engine is operating, fresh air enters the engine and mixes with crankcase vapors. Manifold vacuum draws the vapor/air mixture through the fixed orifice and into the intake manifold. The vapors are then consumed during combustion.