PRINCIPLES GASOLINE/DIESEL FUEL SYSTEMS - OD1620 - LESSON 2/TASK 2
Combustion Chamber Design
a. Open Chamber (figure 39). The open chamber is the simplest form of
diesel chamber design.
It is suitable only for slow-speed, four-stroke
cycle engines, but is also used widely in two-stroke cycle diesel engines.
In the open chamber, the fuel is injected directly into the space at the top
of the cylinder. The combustion space, formed by the top of the piston and
the cylinder head, usually is shaped to provide a swirling action of the air
There are no special
pockets, cells, or passages to aid the mixing of the fuel and air. This
type of chamber requires a higher injection pressure and a greater degree of
fuel atomization than is required by other combustion chambers to obtain a
comparable level of fuel mixing. This chamber design is very susceptible to