low-speed power, and gets much more fuel mileage than
(5) A diesel engine operates well only in low-
the gasoline counterpart. This makes the engine very
speed ranges in relation to gasoline engines. This
suitable for large trucks.
creates problems when using them in passenger cars
that require a wide-speed range.
(2) The diesel engine requires no ignition
e. Usage. Diesel engines are widely used in all
tuneups because there is no ignition system.
types of heavy trucks, trains, and boats. In recent years,
(3) Because diesel fuel is of an oily consistency
more attention has been focused on using diesels in
and less volatile than gasoline, it is not as likely to
explode in a collision.
f. Multifuel Engine (Fig. 2-20). The multifuel
engine is basically a four-stroke cycle diesel engine with
the capability of operating on a wide variety of fuel oils
(1) The diesel engine must be made very
without adjustment or modification (chapter 5, section I).
heavy to have enough strength to deal with the tighter
The fuel injection system is equipped with a device called
compression of the fuel and air mixture.
a fuel density compensator. Its job is to vary the amount
of fuel to keep the power output constant regard- less of
(2) The diesel engine is very noisy.
the fuel being used. The fuel system for the multifuel
engine is described in detail in chapter 5, section I. The
Diesel fuel creates a large amount of
multifuel engine uses a spherical combustion chamber to
aid in thorough mixing, complete combustion, and
minimizing knocks. The spherical combustion chamber is
(4) Because diesel fuel is not very volatile, it is
covered in chapter 5, section II.
difficult to start a diesel engine in cold weather.
Figure 2-20. Multifuel Engine.