PRIN. OF INTERNAL COMBUSTION ENGINES - OD1619 LESSON 1/TASK 1
b. Comparison of Engine Types.
(a) Internal Combustion Engine (figure 10, view A). An internal combustion
engine is any engine in which the fuel is burned from within. A four stroke cycle
engine is an internal combustion engine because the combustion chamber is located
within the engine.
VERSUS EXTERNAL COMBUSTION
(b) External Combustion Engine (figure 10, view B). An external combustion
engine is an engine in which the fuel is burned outside of the engine. A steam
engine is a perfect example. The fuel is burned in an outside boiler where it
makes steam. The steam is piped to the engine to make it run.
(2) Four Stroke Cycle Versus Two Stroke Cycle. The engine described until now
has been a four stroke cycle engine. There is another form of gasoline piston
engine which requires no valve mechanisms and which completes one operating cycle
for every revolution of the crankshaft. It is called a two stroke cycle engine and