engine
Quick Summary
An engine is a device that converts energy into mechanical motion. The most common type is the internal combustion engine, where combustion occurs within the engine itself. These engines typically use a piston and cylinder arrangement.123
In a gasoline engine, the combustion chamber's volume is determined by the piston's position within the cylinder. The engine's efficiency is significantly influenced by its compression ratio, which is the ratio of the maximum to minimum volume of the combustion chamber. This ratio is limited by the fuel's antiknock characteristics, often measured by its octane number.43
Engines can operate on a two-stroke or four-stroke cycle. The four-stroke cycle is common in automobiles, while two-stroke engines are found in smaller applications like outboard motors. Modern automobiles incorporate numerous technological advancements in their design, including sophisticated engine systems, driven by factors like emissions regulations and consumer demand.56
Ask Britannica AI about this topic
Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.
history of flightThe generation and application of power: the problem of propulsion…19th century approached, the internal-combustion engine emerged as an even more promising aeronautical power plant. The process had begun in 1860, when Étienne Lenoir of Belgium built the first internal-combustion engine, fueled with illuminating gas. In Germany, Nikolaus A. Otto took the next step in 1876, producing a four-stroke engine…
Read More…19th century approached, the internal-combustion engine emerged as an even more promising aeronautical power plant. The process had begun in 1860, when Étienne Lenoir of Belgium built the first internal-combustion engine, fueled with illuminating gas. In Germany, Nikolaus A. Otto took the next step in 1876, producing a four-stroke engine…
Read More- history of flightFrom airmail to airlines in the United States
…of development in modern piston engines. Because liquid-cooled in-line engines offered less frontal surface, they were often favoured by military designers. With these engines, aircraft could be streamlined to improve speed but with a trade-off in complexity and weight because of the requisite coolant, coolant lines, radiator, and associated pumps.…
Read More…of development in modern piston engines. Because liquid-cooled in-line engines offered less frontal surface, they were often favoured by military designers. With these engines, aircraft could be streamlined to improve speed but with a trade-off in complexity and weight because of the requisite coolant, coolant lines, radiator, and associated pumps.…
Read More
