3. Read and translate the text. Suspension

When the wheels of a car are travelling along the road they follow all the variations in the surface. When they come to a bump, they go over it, and when they come to a hollow they go into it. If the whole car had to follow all these wheel movements the passengers would have a very jerky ride. The wheels are therefore suspended on springs which help to separate them from the body structure, and even if the road is bumpy and the wheels jump up and down, the remainder of the car remains fairly steady all the time.

Although they smooth out road roughness, springs by themselves have too much bounce and produce a motion rather like that of a small boat on a rough sea. So the suspension system has to include shock absorbers or spring dampers. These smoothly restrict the up and down movement of the springs to give a more level ride.

There are many different suspension systems in use. The conventional arrangement consists of independent front suspension in which the two front wheels are separately sprung, and semi-elliptic rear suspension in which the whole rear axle and wheel assembly is suspended on two long, curved springs.

4. Answer the questions:

1) Why are the wheels suspended on springs?

2) What kind of motion do springs produce?

3) What does the suspension system include?

4) What restricts the up and down movement of the springs to give a more level ride?

5) What does the conventional suspension system consist of?

5. Say with one word:

1 ) hydraulic mechanism that dampens oscillations in the suspension system

2) suspension system that permits each wheel to move up and down independently of the action of the other wheels

Unit 29 Different drives. Different engine designs

1. Memorize the new words and word-combinations:

1.rear engine drive

2.front engine drive

3.rocker

4.stem

5.overhead

задній привід

передній привід

коромисло

шток

верхній

2.Translate the word-combinations:

to drive the rear wheels, to do away with, to have an axle at the rear, to drive the front wheels, conventional drive, rear engine drive, front engine drive, engine design, valve stem, valve rocker, to take interest in something, to operate the various controls, to be some distance from something

3.Translate the word- combinations with compound words:

front-mounted engine, rear-mounted engine, mass-produced cars, side-valve engine, overhead-valve engine, overhead camshaft, horizontally-opposed engine, V-type engine, not-very-efficient design

4. Read and translate the text.

Different drives. Different engine designs

If you have followed the pages of this book so far, you will now have a very good idea of how the main units of a motor car work. But we must not forget that many makes of cars are designed differently.

One common variation is a rear-mounted engine driving the car wheels. Such an arrangement does away with a long propeller shaft; the gearbox and rear axle assemblies being included in the lower part of the engine. This system used to be very popular on the Continent and is still employed on cars such as the Volkswagen Beetle and the small Fiats.

Another arrangement is to have a front-mounted engine driving the front, wheels. The Austin, Morris Minis, 1100/1300's and 1800's are good example of this, but they have the added difference of an engine mounted sideways across the car instead of the usual forward and backward fitting.

In addition to the different methods available for driving the wheels, there are also many different engine designs.

Some years ago the side-valve engine was very popular. In this not very efficient design the valves were placed at the side of the cylinders. The great majority of modern engines are of the overhead-valve type, in which the valves are positioned above the pistons with their heads facing downward. Because the valve stems, in this arrangements, are some distance from the camshaft, push-rods and rockers are normally used to provide the necessary means of operation.

A variation of the overhead-valve design is the overhead camshaft. This does away with push-rods and sometimes rockers, because the camshaft is fitted above the valve stems and can operate directly on them.

There are also the V-type and «horizontally-opposed» engines and others.

The whole subject of cars and engines is a fascinating one. Now you know more about it.