Figure 3-5.Relationship between torque and horsepower.
(intake, compression, power, and exhaust). The
two-stroke-cycle engine completes a cycle with just
one crankshaft revolution. With diesel engine
cycles (two- and four-stroke), the event of fuel
injection will be shown on the timing diagram
instead of spark ignition, which is common to
gasoline engine operating cycles.
Four-Stroke-Cycle Engine Timing
Figure 3-6 shows a typical timing diagram for
a four-stroke-cycle diesel engine. The actual length
of the strokes shown and the beginning of fuel
injection will vary a few degrees in either
direction, depending on the specific manu-
facturers recommendations. Follow the events in
this cycle by tracing the circular pattern
around two complete revolutions in a clockwise
Figure 3-6.Typical timing diagram of a four-stroke-cycle diesel engine.