Introduction
Also known as four cycle engine, four stroke engine is an internal combustion engine in which the piston makes four separate strokes as it turns the crankshaft. A stroke means that the piston travels along the cylinder in any direction. A four stroke engine has for strokes thus giving it its name.
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| Four stroke engine |
The four strokes include Intake, Compression, Ignition and exhaust. By intake I mean, a mixture of fuel and air is drawn into the combustion chamber. This is achieved by the movement of piston downwards in the cylinder, intake valve opens and lets in the mixture. The second stroke, i.e compression, the piston moves back up, all valves closed the air fuel mixture is compressed, temperature and energy potential of the mixture rises,and this goes to the third stroke. A spark plug introduces a spark into the compressed mixture, causing a power explosion in the small space, the piston is pushed down and and as it moves back up on the final stage, the burnt air and fuel, is expelled through the exhaust valve in form of exhaust fumes. These for cycles happen in intervals in an engine so that the crankshaft is always in constant motion.
History
Four stroke engine dates back to the 19th Century and many people claimed its invention. However a german engineer,
Nikolaus August Otto, had a patent of the four stroke operating sequence. He had encountered several engines in his time as a grocery salesman and was looking for ways to improve them since most of them could run a few minutes prior to its destruction. These engines were heavy and less efficient.
In 1864, Otto and
Eugen Langen a german entrepreneur, inventor and engineer, founded a company that manufactured internal combustion engines. The company made several engines and in 1876, Otto and Langen succeeded in creating the first internal combustion engine that compressed the fuel mixture prior to combustion for far higher efficiency than any engine created to this time known to as Otto Engine. That was a great achievement in the engine history.
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| Otto Engine |
The company had two employees named
Gottlieb Daimler and
Wilhelm Maybach. Gottlieb Daimler was technical director and Wilhelm Maybach was the head of engine design.
The two however after some years left the company and created the first highspeed Otto engine in 1883. In the same year also a french engineer
Edouard Dalamare-Debouteville, built a single cylinder four stroke engine that ran on stove gas. In 1885, Daimler and Wilhelm an automobile equiped with the Otto engine, and named it
Daimler Reitwagen. The vehicle used a hot-tube ignition system and the fuel known as Ligroin(a volatile hydrocarbon mixture obtained from petroleum, used as a solvent) to become the world's first vehicle powered by an internal combustion engine. Its structure looked like the modern day motobike.
Karl Friedrich Benz the founder of the current Mercedes Benz company, in 1886 founded the worlds first car with a four stroke engine. In the same year on March 8th Daimler made the first four wheeled automobile.
A V shaped two cylinder engine four stroke engine came into existence in 1889, thanks to its creator Daimler. The engine had mushroom shaped valves. This engine set the basis for all car engines from then going foward. The engine made by Daimler
In1893, the first successful diesel engine was made by
Rudolf Diesel. The high-compression engine, which ignites its fuel by the heat of compression, is now called the diesel engine whether a four-stroke or two-stroke design. The diesel engine has been mostly used in heavy commercial duties since it uses heavy fuel containing more energy and easy to refine.
From 1900, various engineer added improvements to the engine, and it was used commercially, cars and motorcycles were being manufactured with the engine. In 1951, Engineers of The Texas Company, now Chevron, took part in development of a four stroke engine with a fuel injector that employed what was called the Texaco Combustion Process, which unlike normal four stroke gasoline engines which used a separate valve for the intake of the air-gasoline mixture, with the Texaco Combustion Process engine the intake valve with a built in special shroud delivers the air to the cylinder in a tornado type fashion and then the fuel is injected and ignited by a spark plug. The inventors claimed their engine could burn on almost any petroleum based fuel of any octane and even some alcohol based fuels e.g. kerosene, benzine, motor oil, tractor oil, etc. without the pre-combustion knock and the complete burning of the fuel injected into the cylinder. While development was well advanced by 1950, there are no records of the Texaco Combustion Process engine being used commercially.
To date there are still improvements on engines to maximize its efficiency.
