Lesson 1/Learning Event 1
FUNDAMENTALS OF SPARK-IGNITION ENGINES
Describe the fundamentals of spark-ignition engines.
Given information about the principles of operation, construction, and classification of spark-ignition engines.
Solve 70 percent of the multiple-choice test items covering fundamentals of spark-ignition engines.
Learning Event 1:
DESCRIBE PRINCIPLES OF OPERATION, CONSTRUCTION, AND CLASSIFICATION
ORIGIN OF FORCE FOR ENGINE OPERATION
Everyday we see many examples of how heat energy, produced by burning any combustible substance from
wood to gasoline, can be made to perform useful work. When a gun is fired, the burning gunpowder performs
useful work, so let's study its action for a moment.
When you pull the trigger, the firing pin strikes the primer in the shell case. The primer then ignites the
gunpowder. The burning gunpowder expands rapidly and exerts pressure on the bullet. This pressure gets so
high so fast (50,000 pounds per square inch (PSI) or higher in a high-powered Army rifle), it is