Crankcase Ventilation System Description; Ls2 Engine - Chevrolet Corvette 2005 Owner's Manual

2005 Chevrolet Corvette Restoration Kit
Crankcase Ventilation System Description
A closed crankcase ventilation system is used in order to provide a more complete scavenging of
crankcase vapors. Filtered air from the air induction system duct is supplied to the crankcase, mixed with
blow-by vapors, and passes through a crankcase ventilation metering device before entering the intake
manifold. The primary component in the positive crankcase ventilation (PCV) system is the PCV flow
metering device (valve or orifice) . Vacuum changes within the intake manifold result in flow variations of
the blow-by vapors. If abnormal operating conditions occur, the design of the PCV system permits
excessive amounts of blow-by vapors to back flow through the crankcase vent tube and into the engine
induction system to be consumed during normal combustion. This engine ventilation system design
minimizes oil consumption and significantly reduces the potential for oil ingestion during vehicle limit
handling maneuvers.
LS2 Engine
The LS2 engine utilizes an integral PCV system which is located in the engines valley cover beneath the
intake manifold. The engine valley cover contains composite oil separating baffles and PCV plumbing.
Filtered fresh air is routed from up stream of the throttle plate to the front of the right valve rocker arm
cover through a formed nylon tube. The design of the rocker cover shields rocker arm oil spray thereby
reducing the potential for oil being drawn into the throttle bore area during back flow of the ventilation
system. Blow-by vapors are routed from the valley cover through a fixed orifice (2.5 mm) within a steel
PCV tube, then through a formed rubber hose before entering the intake manifold behind the throttle
body.
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