TM 5-3895-359-14&P
AIR INTAKE SYSTEM
CHAPTER 4
CONTENTS
PAGE
Air Intake System.................................................................................................10-4-1
Air Cleaner...........................................................................................................10-4-2
Air Shutdown Housing .......................................................................................... 10-4-5
Blower.................................................................................................................. 10-4-7
Shop Notes - Trouble Shooting - Specifications - Service Tools ........................... 10-4-21
AIR INTAKE SYSTEM
In the scavenging process employed in the 71 In-Line
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
helps to cool the internal engine parts, particularly the
exhaust valves. At the beginning of the compression
stroke, therefore, each cylinder is filled with fresh, clean
air which provides for efficient combustion.
The air, entering the blower from the air cleaner, is
picked up by the blower rotor lobes and carried to the
discharge side of the blower as indicated by the arrows
in Fig. 1.
The continuous discharge of fresh air from the blower
creates an air pressure of approximately 7 psi (48 kPa)
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.
Fig. 1 - Air Flow Through Blower and Engine
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
10-4-1