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The gasoline internal combustion engine principles of operation

The most common type of gasoline engine is known as the four-stroke cycle engine. The piston travels the length of the stroke outward twice and inward twice (1) to produce one power impulse.

Strokes of the four-stroke cycle engine are as follows: 1) intake, 2) compression, 3) power, 4) exhaust.

Intake Stroke. Fuel is taken into the cylinder from the carburettor through the open intake valve and the intake manifold, when there are more than one cylinder. This is possible because air rushing through the carburettor becomes charged with (2) gasoline in finely divided particles as the piston creates a vacuum in the cylinder in moving from the top to the bottom. When the cylinder is filled with this combustible mixture of gasoline and air, the intake valve is closed.

Compression Stroke. When the intake and the exhaust valves are closed, the piston moves from the bottom to the top of the cylinder, compressing the mixture into a small space, known as the combustion chamber. Before the piston has quite reached the, top of the stroke, a spark is introduced and the mixture begins to burn and to expand.

Power Stroke. As the mixture burns, heat is produced. The products of combustion expand because o the heat produced and push the piston downward in the power stroke. As the piston nears the bottom of the power stroke the exhaust valve starts to open and becomes fully open by the time the piston is completely down.

Exhaust Stroke. Most of the exhaust gases leave the cylinder with, a loud explosive noise. The piston moves upwards with the exhaust valve completely open and forces the remaining burned gases out of the cylinder. The exhaust valve is closed shortly after the piston has reached the top of the exhaust stroke and has started down on the intake stroke.

NOTES:

(1) travels the length of the stroke outward twice and inward twice- на протяжении всего хода два раза поднимается и два раза опускается

(2) becomes charged with- насыщается

Learn some new words:

Gasoline – бензин

Stroke – ход, такт

Manifold – коллектор

To rush – поступать

To charge – насыщать, наполнять

To create – создавать

To fill – наполнять

To reach – достигать

Spark – искра

To expand – расширять

To near – достигать

Explosive – взрывчатый

Practice 1. Reread the text and answer the questions:

  1. Name the strokes of the four-stroke cycle engine.

  2. What are the strokes of the four-stroke cycle engine?

  3. What does the combustible mixture contain?

  4. What is produced when the air and fuel mixture burns?

  5. What takes place in the exhaust stroke?

  6. How many times does the piston travel the length of the stroke to produce one power impulse?

Practice 2. Give the English equivalents to the following sentences:

1. Поршень достигает верхней мертвой точки в ходе выхлопа.

2. Продукты горения расширяются и толкают поршень вниз.

3. Существуют двухтактные и четырехтактные двигатели.

4. Цилиндр наполняется горючей смесью воздуха и бензина.

5. Топливо поступает в цилиндр через впускной коллектор.

6. Воздух становится насыщенным бензином.

7. Поршень создает вакуум в цилиндре.

8. Появляется искра и смесь начинает гореть и расширяться.

Practice 3. Match up the words on the left with the definitions on the right:

  1. stroke

  1. piston

  1. manifold

  1. bottom

  1. valve

  1. combustible mixture

  1. engine

Practice 4. Complete the sentences using the words from the box:

Nears; combustible mixture; to burn; to expand; all exhaust gases; expanding; pushing; a spark; impulse.

  1. The piston … the bottom of the power stroke.

  2. The cylinder is filled with … .

  3. The mixture begins … and … .

  4. … leave the cylinder.

  5. The products of combustion are … and are … the piston.

  6. … is introduced.

  7. The piston produces one power … .

Practice 5. Complete the table:

noun

verb

adjective

combustible

mixture

create

power

productive

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