Diesel engine facts for kids

A diesel engine helps power this oil tanker.

A diesel engine is a special type of engine invented by a German man named Rudolf Diesel in the late 19th century. It's one of the most common kinds of internal combustion engine, which means it burns fuel inside to create power.

Most other engines, like those in many cars, need a spark plug to create an electric spark. This spark lights up a mix of fuel and air to make the engine run. But a diesel engine works differently! It doesn't need a spark. Instead, it uses very high compression to make the fuel burn.

Here's how it works: Air is pulled into the engine's cylinders and squeezed very, very tightly. When gases are squeezed, they get super hot. Then, a tiny bit of diesel fuel (which is similar to heating oil) is squirted into this hot, compressed air. Because the air is so hot, the fuel instantly explodes, pushing a part called a piston and making the engine work.

Why Diesel Engines Are So Useful

Diesel engines are great because they use their fuel very well, which means they are fuel-efficient. They also create a lot of torque, which is a strong twisting power. Imagine trying to unscrew a very tight lid – you need a lot of twisting power, or torque!

An engine with lots of torque can spin its parts even when it's really hard to do so. This makes diesel engines perfect for big, heavy machines. You'll find them in large trucks, trains, and construction equipment. The huge trucks you see on highways usually have diesel engines. So do train locomotives, unless they are electric or old steam-powered ones.

Boosting Power with a Turbocharger

Sometimes, even the strong torque of a diesel engine isn't enough for the biggest machines. To get even more power, large diesel engines often have a device called a turbocharger. A turbocharger is like a special fan that moves a lot of air very quickly.

Here's how it helps: The hot exhaust gases from the engine spin the turbocharger at a very high speed. This spinning forces fresh air back into the engine. Since the engine makes power by pumping air, putting more air through it means it can make more power! A diesel engine with a turbocharger is called a turbodiesel. If you hear a whistling sound near one of these engines, it's often the turbocharger, or "turbo" for short.

Diesel Engines and Biodiesel Fuel

Did you know that some diesel engines can also run on canola oil? This oil can be made from old cooking oil! This type of fuel is called biodiesel. When a diesel engine runs on biodiesel, its exhaust might even smell like french fries or other food!

Using vegetable oil as fuel isn't a new idea. When Rudolf Diesel first showed off his new engine, it actually ran on canola oil. This shows how versatile and adaptable diesel engines can be.

Images for kids

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  Diesel engine built by Langen & Wolf under licence, 1898.

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  Rudolf Diesel's 1893 patent on a rational heat motor

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  Diesel's second prototype. It is a modification of the first experimental engine. On 17 February 1894, this engine ran under its own power for the first time. Effective efficiency 16.6% Fuel consumption 519 g·kW−1·h−1

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  First fully functional diesel engine, designed by Imanuel Lauster, built from scratch, and finished by October 1896. Rated power 13.1 kW Effective efficiency 26.2% Fuel consumption 324 g·kW−1·h−1.

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  Diesel engine model, left side

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  Diesel engine model, right side

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  Stationary 12 cylinder turbo-diesel engine coupled to a generator set for auxiliary power

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  The MAN B&W 5S50MC 5-cylinder, 2-stroke, low-speed marine diesel engine. This particular engine is found aboard a 29,000 tonne chemical carrier.

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  Schematic of a two-stroke diesel engine with a roots blower

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  Detroit Diesel timing

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  Ricardo Comet indirect injection chamber

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  Typical early 20th century air-blast injected diesel engine, rated at 59 kW.

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  1980s BMW M21 passenger car turbo-diesel engine

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  The MAN 630's M-System diesel engine is a petrol engine (designed to run on NATO F 46/F 50 petrol), but it also runs on jet fuel, (NATO F 40/F 44), kerosene, (NATO F 58), and diesel engine fuel (NATO F 54/F 75)

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  One of the eight-cylinder 3200 I.H.P. Harland and Wolff – Burmeister & Wain diesel engines installed in the motorship Glenapp. This was the highest powered diesel engine yet (1920) installed in a ship. Note man standing lower right for size comparison.

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  Air-cooled diesel engine of a 1959 Porsche 218

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  Three English Electric 7SRL diesel-alternator sets being installed at the Saateni Power Station, Zanzibar 1955

See also

In Spanish: Motor diésel para niños