Let me tell you about each part separately. After we have gone over each part you will find that you will understand the action of the motor and other parts of the car well enough so that you will unconsciously reason it all out for yourselves. Some of the descriptions and explanations may at first seem unsatisfactory, but I think with a little thought and study you will be able to master them in a short time. I want your confidence, boys, and then I know we will get along all right together.
Fig. 2—A Single-cylinder Horizontal Engine. Note location of valves in this type.
Suction Stroke Compression Stroke Working Stroke Exhaust Stroke
Fig. 3—Four views of a section of a Vertical Cylinder, showing position of valves, pistons and cams for the four different strokes.
THE FOUR-STROKE CYCLE.
This subject looks like a bugbear, doesn’t it. Well, it is one of the first things of which we shall have to dispose, and so we’ll tackle it right away. We will start backwards, and take the word cycle first. If you will look in the dictionary you will find that this word means “a circle or orbit; an interval of time in which a succession of events is completed, and then returns in the same order.”
Suction Stroke
Compression Stroke
Working Stroke
Exhaust Stroke