A piston is a component of reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. In a pump, the function is reversed and force is transferred from the crankshaft to the piston for the purpose of compressing or ejecting the fluid in the cylinder. In some engines, the piston also acts as a valve by covering and uncovering ports in the cylinder.
A reciprocating engine, also often known as a piston engine, is typically a heat engine that uses one or more reciprocating pistons to convert high temperature and high pressure into a rotating motion. This article describes the common features of all types. The main types are: the internal combustion engine, used extensively in motor vehicles; the steam engine, the mainstay of the Industrial Revolution; and the Stirling engine for niche applications. Internal combustion engines are further classified in two ways: either a spark-ignition (SI) engine, where the spark plug initiates the combustion; or a compression-ignition (CI) engine, where the air within the cylinder is compressed, thus heating it, so that the heated air ignites fuel that is injected then or earlier.
A two-strokeengine is a type of internal combustion engine that completes a power cycle with two strokes of the piston during one power cycle, this power cycle being completed in one revolution of the crankshaft. A four-stroke engine requires four strokes of the piston to complete a power cycle during two crankshaft revolutions. In a two-stroke engine, the end of the combustion stroke and the beginning of the compression stroke happen simultaneously, with the intake and exhaust functions occurring at the same time.
An opposed-piston engine is a piston engine in which each cylinder has a piston at both ends, and no cylinder head. Petrol and diesel opposed-piston engines have been used mostly in large-scale applications such as ships, military tanks, and factories. Current manufacturers of opposed-piston engines include Cummins, Achates Power and Fairbanks-Morse Defense (FMDefense).
Puch is a manufacturing company located in Graz, Austria. The company was founded in 1899 by the industrialist Johann Puch and produced automobiles, bicycles, mopeds, and motorcycles. It was a subsidiary of the large Steyr-Daimler-Puch conglomerate.
A U engine is a piston engine made up of two separate straight engines placed side-by-side and coupled to a shared output shaft. When viewed from the front, the engine block resembles the letter "U".
The Chevrolet small-block engine is a series of gasoline-powered V8 automobile engines, produced by the Chevrolet division of General Motors between 1954 and 2003, using the same basic engine block. Referred to as a "small-block" for its size relative to the physically much larger Chevrolet big-block engines, the small block family spanned from 262 cu in (4.3 L) to 400 cu in (6.6 L) in displacement. Engineer Ed Cole is credited with leading the design for this engine. The engine block and cylinder heads were cast at Saginaw Metal Casting Operations in Saginaw, Michigan.
The two-stroke power valve system is an improvement to a conventional two-stroke engine that gives a high power output over a wider RPM range.
A motorcycle engine is an engine that powers a motorcycle. Motorcycle engines are typically two-stroke or four-stroke internal combustion engines, but other engine types, such as Wankels and electric motors, have been used.
The Honda NR was a V-four motorcycle series started by Honda in 1979 with the 500cc NR500 Grand Prix racer that used oval pistons. This was followed during the 1980s by a 750cc endurance racer version known as the NR750. The oval piston concept allowed for eight valves per cylinder which generated more power due to the increased air/fuel mixture and throughout compression. In 1992 Honda produced around 300 street versions of a 750cc model, the NR, with a 90-degree V angle. Whereas the NR500 had used an oval piston with straight sides, the road going NR750 used an elliptical piston with curved long sides. The bike became the most expensive production bike at the time when it was selling for $50,000 and with the rarity, nowadays they rarely change hands.
A single-cylinder engine, sometimes called a thumper, is a piston engine with one cylinder. This engine is often used for motorcycles, motor scooters, go-karts, all-terrain vehicles, radio-controlled vehicles, portable tools and garden machinery. Single-cylinder engines are made both as 4-strokes and 2-strokes.
The Yezdi Roadking was a motorcycle produced in India by Ideal Jawa Ltd, Mysore from 1978 to 1996. It was based on the CZ 250 motocross ridden by Jaroslav Falta to the runner-up spot in the 1974 motocross world championship. It was sold under the brand name Yezdi. The bike won several Indian rallies and road races. The bike had a 250 cc engine with dual exhausts and a semi-automatic clutch and Jawa/CZ's trademark integrated gear shifter/kick-starter.
The MV Agusta 500cc Three (1965–1973) or MV Agusta Tre was a road racing motorcycle produced by the Italian manufacturer MV Agusta to compete in the 500 cc Grand Prix motorcycle racing World Championship. The motorcycle was introduced in 1966 to compete against the ever competitive Honda racing machines and was a bored out version of MV Agusta's highly successful 350 cc three cylinder. Giacomo Agostini won consecutive world championships in the 500 cc class with this motorbike from 1966 to 1972. In addition, MV Agusta won the Constructors' World Championships from 1967 to 1972. The MV Agusta Tre is considered the most successful racing motorcycle in history.
Triumph-Werke Nürnberg AG or TWN, was a German bicycle and motorcycle company. In 1886, Siegfried Bettmann founded the Triumph bicycle factory in Coventry, England, and in 1896 he founded a second bicycle factory in his native Nuremberg, Germany, under the same Triumph name. Both factories branched out into making motorcycles: the Coventry factory in 1902 and the Nuremberg factory in 1903.
EMC Motorcycles or the Ehrlich Motor Co was a British motorcycle manufacturer. Based in Isleworth, the business was founded by Joseph Ehrlich who emigrated to the United Kingdom from Austria in the 1930s.
The Puch 250 SGS (Schwing-Gabel-Sport) is a motorcycle that was manufactured by the Austrian Steyr Daimler Puch AG's Puch division in Thondorf near Graz. The motorcycle is powered by a split-single two-stroke engine. It was marketed in the United States by Sears as the "Allstate 250" or "Twingle", with the model number SR 250, and sold primarily via the Sears catalog. It was a common "first motorcycle" for many riders.
A desaxe engine, is one in which each cylinder is positioned with its exact center slightly offset from the center line of the crankshaft. "Désaxé", in French, means "unbalanced". Desaxe engines are usually automotive, but the term can also apply to steam engines.
In an internal combustion engine, the geometry of the exhaust system can be optimised ("tuned") to maximise the power output of the engine. Tuned exhausts are designed so that reflected pressure waves arrive at the exhaust port at a particular time in the combustion cycle.
An internal combustion engine is a heat engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combustion engine, the expansion of the high-temperature and high-pressure gases produced by combustion applies direct force to some component of the engine. The force is typically applied to pistons, turbine blades, a rotor, or a nozzle. This force moves the component over a distance, transforming chemical energy into kinetic energy which is used to propel, move or power whatever the engine is attached to.
