TM 5-3895-346-14
AIR INTAKE SYSTEM
ENGINE OVERHAUL
AIR INTAKE SYSTEM
In the scavenging process employed in the Series 53 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 enters the air chamber of the cylinder block and sweeps through the intake ports of the cylinder
liners.
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
Figure 1. Air Flow Through Blower and Engine (In-Line Engine)
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