TM 53810-300-24&P-3
3
SECTION 3
AIR INTAKE SYSTEM
CONTENTS
Air Intake System ..................................................................................................................
Air Cleaner.............................................................................................................................
Air Shutdown Housing ...........................................................................................................
Blower....................................................................................................................................
Shop Notes - Trouble Shooting - Specifications - Service Tools.........................................
AIR INTAKE SYSTEM
In the scavenging process employed in the 71 In-Line
with fresh, clean air which provides for efficient
engines, a charge of air is forced into the cylinders by the
blower and thoroughly sweeps out all of the burned
gases through the exhaust valve ports. This air also
The air, entering the blower from the air cleaner, is
helps to cool the internal engine parts, particularly the
picked up by the blower rotor lobes and carried to the
exhaust valves. At the beginning of the compression
discharge side of the blower as indicated by the arrows
stroke, therefore, each cylinder is filled
in Fig. 1. The continuous discharge of fresh air from the
blower creates an air pressure of approximately seven
pounds per square inch in the air chamber of the cylinder
block at maximum engine speed. This air sweeps
through the intake ports, which start to open as the
piston approaches the end of its downward travel and
close after the compression stroke begins.
The angle of the ports in the cylinder liners creates a
uniform swirling motion to the intake air as it enters the
cylinders.
This motion.
persists throughout the
compression stroke and facilitates scavenging and
Fig. 1 - Air Flow Through Blower and Engine
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