The primary control is through the crankcase ventilation valve which meters the flow at a rate depending on manifold vacuum. To maintain idle quality, the crankcase ventilation valve restricts the flow when intake manifold vacuum is high. If abnormal operating conditions arise, the system is designed to allow excessive amounts of blow-by gases to back flow through the crankcase vent tube into the engine air inlet to be consumed by normal combustion.

The engine ventilation system was developed to minimize oil consumption and ensure that oil ingestion could not occur during vehicle limit handling maneuverers. Filtered fresh air is routed from up stream of the throttle blade to the front of the right rocker cover via a formed rubber hose. To reduce the potential of oil pullover into the throttle bore area due to back flow of the ventilation system, the fitting in the right side rocker cover is shielded from the rocker arms and their oil spray. Blow-by gases are routed from the rear of both rocker covers, through molded nylon lines to a tee fitting located on the centerline of the engine at the rear of the intake manifold. From there, a single nylon line carries the blowby gases through an externally mounted, horizontal PCV valve and enters the intake manifold behind the throttle body.

(1)	Throttle Body
(2)	Fresh Air
(3)	PCV Valve
(4)	Crankcase Gases

The dual draw system was develop to meet harsh handling maneuver requirements. During sustained maximum lateral accelerations, the outboard rocker cover may fill with oil. The dual draw system passively switches, allowing the PCV valve to draw on the rocker cover with the least resistance. This results in the system drawing on the air filled, or inboard rocker cover and eliminates oil pullover due to drawing on the oil-filled outboard rocker cover.

PCV System

The PCV valve is connected to the PCV heat exchange cable. The PCV heat exchange cable is mounted to the coolant crossover with a integral fastener (3). This cable transfers heat to the PCV valve to eliminate condensation build-up in the PCV system. This also aids in eliminating throttle body icing.

Results of Incorrect Operation

A plugged PCV valve or hose may cause:

•	Rough idle

•	Stalling or slow idle speed

•

Oil leaks

•	Sludge in engine

A leaking valve or hose would cause:

•	Rough idle

•

Stalling

•	High idle speed