SUBSECTION 11D
A I R INTAKE SYSTEM
GENERAL
This subsection contains repair informa-
tion on the blower and turbocharger.
DESCRIPTION
In the scavenging process employed in
this engine, a charge of air is forced in-
to the cylinders by the blower and thor-
oughly sweeps o u t a l l o f t h e b u r n e d
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 com-
pression stroke, therefore, each cylinder
is filled with fresh, clean air which pro-
vides for efficient combustion.
The air, entering the blower from the air
cleaner is picked up by the blower rotor
F i g u r e 11D-1. Air Flow Through
lobes and carried to the discharge side
B l o w e r and Engine
of the blower as indicated by the arrows
The continuous dis-
turn a single stage turbine wheel which
charge of fresh air from the blower
drives an impeller thus supplying air
creates an air pressure of approximately
under pressure to the blower.
Even
7 psi (48 kPa) in the air chamber of the
though the blower speed is reduced con-
cylinder block at maximum engine speed.
siderably through an additional pair of
This air sweeps through the intake
gears in the blower gear train, the air
box pressure is nearly doubled by the
ports, which starts to open as the piston
increased flow of air and the result is
approaches the end of its downward
freer breathing, quieter operation and
travel and close after the compression
more
stroke begins.
complete
combustion
and
scavenging.
The angle of the ports in the cylinder
liners creates a uniform swirling motion
to the intake air as it enters the cylin-
BLOWER
ders.
This motion persists throughout
the compression stroke and facilitates
scavenging and combustion.
Description
The blower, designed especially for effi-
Turbopowering of the engine is accom-
cient diesel operation, supplies the fresh
plished by introducing a turbocharger in
air needed for combustion and scaveng-
series with the blower of the air system
Its operation is similar to that of a
ing.
as i l l u s t r a t e d i n F i g u r e 1 1 D - 2 o n p a g e
gear type oil pump,
Two hollow three
The expanding exhaust gases
11D-2.
S u b s e c t i o n 11D
