Learn some new words:

1. spark ignition engine – двигатель с искровым зажиганием

2. compression ignition engine – двигатель с компрессионным зажиганием

3. petrol tank – топливный резервуар

4. fuel pipe – топливная трубка

5. governor – ведомый механизм

6. outlet – выходной

7. via – через

8. to handle – брать руками, иметь дело с кем-либо, с чем-либо

9. magneto – магнето

10. to ignite – зажигать

11. to insulate – изолировать

12. wire – провод

13. explosive mixture – взрывчатая смесь

14. condenser – конденсатор

15. coil – катушка

16. contact breaker – прерыватель контакта

17. soft iron core – железное ядро, сердцевина

18. to earth – заземлять

19. frame – рама

20. continuously – постоянно

21. circuit – цепь

22. to extend – протягиваться, вытягиваться, простираться

23. distributor – крышка распределителя

24. plug cables – провода зажигания

25. spark plug – свеча зажигания

26. primary – первичный

27. secondary – вторичный

28. current – ток

29. to cut – прерывать (цепь)

30. to induce – индуцировать, вызывать

31. essential – неотъемлемая часть

Practice 1. Reread the text and answer the questions:

1. What details does the fuel system consists of?

2. What machine is used for producing a spark?

3. What does a magneto consists of?

4. What are the main parts of the secondary circuit?

5. What types of engines are there?

Practice 2. Give the English equivalents to the following words and word combinations:

Свеча зажигания

Тонкие провода

Взрывчатая смесь

Произвести искру

Воспламенять

Провода смотаны

Железная сердцевина

Вторичная катушка

Первичная цепь

Двигатель компрессионного зажигания

Изолированные провода

Вал вращается

Ток высокого напряжения

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

magneto
carburetor
manifold
circuit
current
ignition
mixture

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

Current; magneto; bridged; core; insulated; coil; electric.

1. … is used to produce a spark.

2. The main part of the magneto is … of insulated wire.

3. Two … can be bridged in the circuit

4. Low-voltage … will be induced in the circuit.

5. Insulated wire is wound round the iron … .

6. This wire is electrically … .

7. …current is the cause of spark and ignition of the fuel and air mixture.

Practice 5. Complete the table:

noun	verb	adjective
rotor
	insulate
connection
		inductive
	ignite

The modern farm tractor

Peculiarities.Tractors may be classified according to type of engine, i.e. how the fuel gets into the cylinder. An internal combustion engine is one in which the fuel is burned, and the power is generated within a closed cylinder.

An external combustion engine is one in which the fuel is burned outside of the cylinder, and the power generated is confined in a separate space to be released through the cylinder.

The engine used may be two or four cycles; single or multiple cylinder; manifold or solid injection; low, medium, or high compression; but it is still an internal combustion engine. As such, it requires constant, systematic care and maintenance to insure greatest efficiency and long life.

The modern farm tractor is the result of many years of development. Its present efficiency is possible because of engineering progress in design, metallurgy fuels, lubricants, manufacturing methods and in many other respects. The modern tractor may be said to be very closely related to the modern automobile, truck, airplane, all of them having one feature in common: the internal combustion engine.

The farm tractor is capable of working long hours at capacity loads in the heat and dust of summer or in the cold and snow of winter. Long continued good performance is known to depend upon the operator.

A careless operator can allow a tractor motor to ruin itself in a few minutes, whereas a careful operator can prolong indefinitely the useful life and efficiency of a similar motor. Small difficulties are to be prevented from becoming large ones which may be time consuming and expensive.

Tractor engine fuels.The tractor engine cannot burn both gasoline and distillate. The tractor engines are to be designed specifically for either one fuel or the other.

Need for Tests. We were asked 1) to develop instruments and test methods which would permit accurate testing of tractors under all conditions of operation and 2) to explore the power and economy possibilities of distillate and gasoline.

As it was entirely possible for engineers to sit down with pencil and paper and figure out the relative efficiency and economy values of these two fuels, we did that. We knew in advance that distillate contains more heat units than gasoline, but we also knew that the number of heat units is not the true test of the efficiency of a fuel. Tar, for example, has more heat units than either gasoline or distillate, but it is totally unsuited for internal combustion engine fuel.

The high manifold temperatures required to vaporize low-grade fuels have the effect of reducing engine power by raising the temperature of the air in the fuel mixture. The heavy parts of these fuels often do not vaporize and simply run down the cylinder walls, washing away the lubricating oil, and diluting the oil in the crankcase. Taking all these factors into consideration we figured out that, theoretically, gasoline should develop 29,6 per cent more power than distillate.

Laboratory tests. The next step was to take a tractor into the laboratory and see how theory stood up under actual operating conditions.

We spent a considerable amount of time designing and installing measuring. First, there was an electric dynamometre to test the power at the belt under controlled conditions. Thermometres were installed to measure the temperature of cooling water, crankcase oil, and lubricants in the transmission and differential.

Engine speed was checked by means of an electric tachometer indicator. A flashing neon-tube continuously indicated ignition timing. Fuel and air consumption were measured too.

Great care was exercised in the selection of fuels, particularly distillate. The best distillate available was used. It should be pointed out, however, that there is a considerable variation in the quality of distillate throughout the country. The gasoline used for testing was the regular grade and samples were uniform.

Each fuel was put to work under engine conditions best suited to it. For distillate, hot spark plugs, hot manifold, and a cylinder head of 4.32:1 compression ratio were used. For gasoline, cold-type plugs, cold manifold, and a compression ratio of 6.14:1 were used.

Under the same loads and at the same engine speeds gasoline was found to develop slightly over 26 per cent more power than distillate. The fuel saving amounted to approximately 20 per cent by weight.

Under various other conditions the difference between the efficiencies of the two fuels were even more marked.

The program next called for tests in the field.

The site selected for the field tests was Murve Dry Lake on the Mohave desert, in California.

Load was applied by towing another tractor. Additions and modifications in instrumentation had to be made for exact measuring of power at all times under new conditions. In general, the test methods were the same as those used in the laboratory, same engine speeds, compression rations, fuel mixtures, and so on.

After months of work in all kinds of weather we came to the following conclusions: on the average, gasoline developed 27 per cent more power at the real wheels than distillate; gasoline did each unit of work on 21 per cent less fuel, by weight.

Practice 1. Reread the text and answer the questions:

1. What is Internal Combustion Engine?

2. What is External Combustion Engine?

3. What are types of engines?

4. Why is gasoline preferable to distillate?

Practice 2. Give the Russian equivalents to the following words and word combinations:

Conditions suited to it

To develop power

Under controlled conditions

To install thermometers

The difference between

Cold-type plugs

Heat and dust conditions

It requires systematic care and maintenance

External combustion engine

To burn both gasoline and distillate

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

distillate
plug
efficiency
speed
load
cylinder
temperature

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

Current; magneto; bridged; core; insulated; coil; electric.

1. We … the great care in the selection of fuel.

2. Gasoline developed over 26 per cent power than … .

3. Rotating … must be lubricated.

4. High temperature was reached to ignite fuel and air … .

5. Ignition system may be of … types.

6. This engine is … on gasoline.

7. The high compression in the cylinder can … fuel and air mixture.

Practice 5. Complete the table:

noun	verb	adjective
	reduce
injection
	load
automation
	divide