II. Look through the text again and answer the following questions:

1. What is the difference between the internal-combustion engine and an external-combustion device?

2. Why had the internal-combustion engine replaced the steam engine By the early 1900s?

3. Who is generally credited with having built the first practical internal-combustion engine?

4. How did Gottlieb Daimler, another German engineer, modify the four-cycle Otto engine?

5. Why was the diesel engine more efficient than engines of the Otto variety?

III. Match the words with their definitions and make up your own sentences with these words:

steam	a) the hot gas that water changes into when it boils;
chamber	b) to combine with oxygen;
fluid	c) a hard black mineral found below the ground, used for burning;
to oxidize	d) an enclosed space in certain types of machinery;
efficiency	e) any liquid substance;
to modify	f) the ability to work well and without wasting time or resources;
coal	g) to change smth slightly;
volatile	h) an enclosed ship that can operate under water as well as on the survace;
motorcycle	i) changing rapidly into a gas;
submarine	g) a road vehicle with two wheels, driven by an engine;

IV. Find the information about new engine performance. While looking for information you are free to use the internet sites given below as well as any other online resources.

Make a short presentation in front of the class.

Resources recommended:

www.automobile.com

www.wikeipedia.com

www.autogazeta.com

www.klaxon-media.ru

www.autoreview.ru

www.motorcars.com

Text 23

I. Read the text about different kinds of diesel engines and their application. Major types of diesel engines

There are three basic size groups of diesel engines based on power—namely, small, medium, and large. The small engines have power output values of less than 188 kilowatts, or 252 horsepower. This is the most commonly produced diesel-engine type. These engines are used in automobiles, light trucks, and some agricultural and construction applications, and as small stationary electrical power generators (such as those on pleasure craft) and as mechanical drives. They are typically direct-injection, in-line, four- or six-cylinder engines. Many are turbocharged with aftercoolers.

Medium engines have power capacities ranging from 188 to 750 kilowatts, or 252 to 1,006 horsepower. The majority of these engines are used in heavy-duty trucks (those of the class 6, 7, and 8 variety). They are usually direct-injection, in-line, six-cylinder turbocharged/aftercooled engines. Some V-8 and V-12 engines also belong to this size group.

Large diesel engines have power ratings in excess of 750 kilowatts. These unique engines are used for marine, locomotive, and mechanical drive applications and for electrical power generation.

In most cases, they are direct-injection, turbocharged/aftercooled systems. They may operate at as low as 500 revolutions per minute when good reliability and durability are critical.