Gasoline Engines

Gas engines are known as internal combustion engines
and are divided into two general classes, specifically
two cycle and four cycle engines. A cycle of an
engine represents one stroke of the piston or one
half revolution of the crank shaft, as a complete
revolution represents two cycles. With a two cycle
engine, the power impulse occurs at each revolution,
while with four cycle engines it occurs at every
other revolution, hence the terms two and four cycle
engines.

Both classes have their own specific advantages and
uses. For autombiles, the four cycle engines is
most used. For motor boats on the other hand, the
two cycle engine is most often used.

The horse power of gas engines is designated as HP
and also brake test HP. The IHP is the theoretical
HP, which is found by figuring different formulas,
in which the diameter of the bore, length of the
stroke in inches, and number of revolutions per
minute form the basis for calculation. The results
are found by the use of such formulas.

The BTHP on the other hand, is the power the engine
actually develops in service, and is considerably
less than the IHP. Keep in mind, this depends upon
the degree of the mechanical perfection attained in
the construction of the same. If both the compression
and construction are good, the engine may actually
reach 80 - 88% of the intended IHP.

With gasoline engines, high HP and high RPM ranges
are what makes them popular. Gas engines have always
been more popular than diesel vehicles, for the simple
fact that they can achieve more speed. If speed
is what you are after, gasoline vehicles are what
you should be looking for. Although they may lack
in torque and raw power, they make up for it with
speed and tuning options.