Farymann Diesel 15D Series, Workshop Manual

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5
I.1. Introduction to Diesel Engines
Nowadays diesel engines are well known and quite common in all kinds of machinery and
equipement as an alternative to the well established gasoline engine.
Most people who are fully familiar with gasoline engines are reluctant to deal with a Diesel. This
is without any reason, in fact,
you already know more about a Diesel than you may have
thought. If you are already familiar with the gasoline 4-stroke engine, study the comparison
below. It will show the differences between a 4-stroke Diesel and a 4-stroke gasoline engine.
Gasoline Diesel
I. Intake stroke
The downwards movement of the piston
draws a mixture of gaseous fuel and air
through the open inlet valve into the
cylinder.
II. Compression stroke
The upwards movement of the piston
compresses the fuel/air mixture. The
temperature rises through the
compression stays below the self-ignition
point of the fuel.
The downwards movement of the piston
draws only air through the open inlet valve
into the cylinder.
The upwards movement of the piston
compresses the air, which causes the
temperature to rise above 500 C (932 F).