2.1.1
DETROIT DIESEL 53
FUEL INJECTOR (NEEDLE VALVE)
1. Creates the high fuel pressure required for efficient
The fuel injector (Figs. 1 and 2) is a lightweight
injection.
compact unit which enables quick. easy starting
directly on diesel fuel and permits the use of a simple
2. Meters and injects the exact amount of fuel required
open type combustion chamber. The simplicity of
to handle the load.
design and operation provides for simplified controls
and easy adjustment. No high pressure fuel lines or
3. Atomizes the fuel for mixing with the air in the
complicated air-fuel mixing or vaporizing devices are
combustion chamber.
required.
4. Permits continuous fuel flow.
The fuel injector performs four functions:
Combustion required for satisfactory engine operation
is obtained by injecting. under pressure, a small
quantity of accurately metered and finely atomized
fuel oil into the cylinder.
Metering of the fuel is accomplished by an upper and
lower helix machined in the lower end of the injector
plunger. Figure 3 illustrates the fuel metering from
no-loud to full-load by rotation of the plunger in the
bushing
Fig. 2- Cutaway View of Fuel lnjector
Fig. 1 Fuel Injector Assembly
SEC. 2.1.1 Page 1
March, 1973
