PRIN. OF INTERNAL COMBUSTION ENGINES - OD1619 LESSON 1/TASK 2
(1) In a diesel engine the fuel and air mixture is ignited by the heat generated
by the compression stroke, versus the use of a spark ignition system in a gasoline
The diesel engine therefore needs no ignition system.
For this reason,
the gasoline engine is referred to as a spark ignition engine and a diesel engine
is referred to as a compression ignition engine.
(2) In a diesel engine the fuel and air mixture is compressed to about one-
twentieth of its original volume.
In contrast, the fuel and air mixture in a
diesel engine must compress the mixture this tightly to generate enough heat to
ignite the fuel and air mixture. The contrast between the two engines is shown in
figure 26 on the following page.
THE FOUR STROKE CYCLE DIESEL.