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5. Read the text and insert the missing words
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5. Read the text and insert the missing words
Principle of Engine Operation
There are some principles of engine operation. Engines operate on cycles. There are 1_____________strokes of the piston in one cycle of engine operation. There are two outward strokes toward the crankshaft and 2___________ inward strokes away from the crankshaft. When the piston is at the end of the stroke away from the crankshaft (inward stroke) this is the top 3______________ centre (TDC). When the piston is at the end of the outward stroke (toward the crankshaft) this is the 4____________dead centre (BDC). The piston movement from TDC to BDC is an engine stroke. The four strokes in a cycle of the internal combustion engine are intake, 5_____________, power and 6____________.
6. Polisemic “as”
| as - когда As the piston reaches the top dead center, the spark plug ignites a spark, allowing the fuel to burn. as – так как The piston goes upwards and, as both valves are closed, the mixture is compressed as - как Combustion engines include internal combustion engines such as gasoline ones and external combustion engines such as steam ones. |
Read and translate the sentences
1. As the piston moves inside the cylinder it transforms the energy from the expansion of gases into mechanical power.
2. As the piston goes down, it creates a vacuum in the cylinder.
3. As the piston reaches the top dead center, the spark plug ignites the air-fuel mixture.
4. As the piston reaches the bottom, the exhaust valve opens.
5. As in the case of the four-stroke engine, a spark plug at the top of the cylinder ignites the mixture as the piston reaches the end of its stroke.
6. The piston moves down the cylinder and as the inlet valve is opened air is sucked into the cylinder through the inlet port.
7. The earliest internal combustion engines used coal gas as their fuel.
8. A steam engine is a heat engine that performs mechanical work using steam as its working fluid.
9. The term internal combustion engine usually refers to an engine in which combustion is intermittent, such as four-stroke and two-stroke piston engines.
10. The internal combustion engine is quite different from external combustion engines, such as steam or Stirling engines.
11. The Ford Company is famous as a technologically advanced manufacturer of vehicles.
12. As the mixture burns, it expands and forces the piston down on its power stroke.
13. As the mixture burns, it expands and forces the piston down.
14. The flywheel, a heavy and carefully balanced disc that is fitted at the gearbox end of the crankshaft, helps smooth running as it maintains a steady rate of turning.
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15. In a diesel engine the fuel is compressed so much that it becomes as hot as red-hot iron.
16. Inventors began to experiment with the internal combustion engine as a source of power for flying machines.
7. Watch out
| Because – потому что, e. g. Two-stroke engines are less efficient than four-stroke enginesbecause they use more petrol to do the same amount of work. Because of - из-за, следствие, e. g. Because of the heat of combustion, all engines must be equipped with some type of cooling system. |
Read and translate the sentences
1. Because of the high temperature of operation, a diesel engine must be water-cooled.
2. A diesel engine must be water-cooled because it operates at high temperature.
3. The fuel burns instantly because of the high temperature of the air in the combustion chamber.
4. The fuel burns instantly because the compressed air in the combustion chamber is at high temperature.
5. Diesel engines are more massive than gasoline engines of the same power because of the higher combustion pressure needed for ignition.
6. Diesel engines are more massive than gasoline engines of the same power because they need a higher pressure for ignition.
7. Diesel fuel is more difficult to ignite because of its higher ignition point.
8. Diesel fuel is more difficult to ignite because its ignition point is higher than the ignition point of petrol.
9. Because of the heat that is produced by an internal combustion engine, it requires a cooling system.
10. Because of the heat that is produced by an internal combustion engine, it requires a cooling system.
8. Read the texts and choose the alternative in brackets
The simplest form of 4-stroke engine has a single cylinder, but this is not acceptable in a car (because / because of) the uneven torque which results from only one power stroke at every second revolution of the crankshaft, and (because / because of) the vibration that causes.
Describing processes
9. Put down the derivatives of the verbs
| verb | noun | participle |
| to increase | ||
| to decrease | ||
| to reduce | ||
| to produce | ||
| to cause | ||
| to transmit | ||
| to convert | ||
| to heat |
10. Read the text and choose the correct word form
As the piston (reaches/reaching/reached) the lower limit of its (move/movement/moving/moved), the exhaust valve opens. The piston moves upward on the exhaust stroke, (force/forcing/forced) the burned gases out of the cylinder through the exhaust-valve opening. At the instant that the piston once more (reached/reaching/reaches) top dead center, the exhaust valve closes and the intake valve opens so that, when the piston begins to (movement/move/movement/moved) downward on the intake stroke, a fresh charge of gasoline and air can be (draw/drawn/drawing) into the cylinder. The above four strokes are continually repeated during the operation on the engine.
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