The Boxer engine, first patented by German engineer Karl Benz

A flat engine is an internal combustion engine with pistons that are all relatively horizontal. A straight engine canted 90 degrees from straight up is a flat engine, as is one in which the cylinders are arranged in two banks on either side of a single crankshaft. In both configurations, the motion of all the pistons is in the horizontal plane. Diagram of a boxer engine (opposing pistons and crankshaft), created in Adobe Photoshop by RadicalBender. ... Diagram of a boxer engine (opposing pistons and crankshaft), created in Adobe Photoshop by RadicalBender. ... This article does not cite any references or sources. ... Usually found in 4 and 6 cylinder configurations, the straight engine (often designed as inline engine) is an internal-combustion engine with all cylinders aligned in one row, with no or only minimal offset. ... Cylinder with piston in a steam engine A cylinder in the central working part of a reciprocating engine, the space in which a piston travels. ... Crankshaft (red), pistons (gray) in their cylinders (blue), and flywheel (black) Continental engine marine crankshafts, 1942 Components of a typical, four stroke cycle, DOHC piston engine. ...

German engineer Karl Benz patented his design for the first internal combustion engine with horizontally opposed pistons in 1896. There are two main types of these engines: Karl Benz Karl Friedrich Benz (November 25, 1844 – April 4, 1929) was a German engine designer and automobile engineer, generally regarded as the inventor of the gasoline-powered automobile. ... For other uses, see Patent (disambiguation). ... For the use of the term in optics, see piston (optics). ... Year 1896 (MDCCCXCVI) was a leap year starting on Wednesday (link will display calendar). ...

• The boxer engine (also known as a horizontally opposed engine) in which the corresponding pistons reach top dead centre simultaneously. Boxer engines should not be confused with opposed piston engines, which use a completely different concept.

• The 180° V engine, in which corresponding pistons share a crank pin, and thus each will reach top dead centre half a crankshaft revolution after the other. Flat engines with more than eight cylinders are most commonly V engines.

In German, the term for flat engine is boxermotor, which includes both types, not just those known as boxer engines in English. Look up top dead center in Wiktionary, the free dictionary. ... Fairbanks-Morse opposed piston diesel engines on the submarine USS Pampanito. ... A V engine is a common configuration for an internal combustion engine in which the pistons are aligned so that, if viewed along the line of the crankshaft, they appear to be in a V. Usually, two opposing pistons share one crank on the crankshaft. ... Piston and connecting rod from an automobile engine, showing the big end bearing at the bottom. ... The English language is a West Germanic language that originates in England. ...

Configuration

Flat engines are more compact than in-line engines, and have a lower center of gravity than any other common configuration. Automobiles and motorcycles powered by a flat engine generally have a lower center of gravity, giving better stability and control. These engines, however, are also wider than more traditional configurations and are more expensive to build. The extra width may cause problems fitting the engine into the engine bay of a front-engined car owing to the interference with the steering wheels, and create cornering problems for a motorcycle. This article or section may contain original research or unverified claims. ... Karl Benzs Velo model (1894) - entered into the first automobile race An automobile or motor car (usually shortened to just car) is a wheeled passenger vehicle that carries its own motor. ... MotorCycle is the title of a 1993 album by rock band Daniel Amos, released on BAI Records. ...

The flat configuration also fits very well with air cooling and aircraft engines. Air-cooled designs such as in the VW Beetle used a flat-4, as did the Porsche 356 and 912. The Chevrolet Corvair used an air-cooled flat-6, a rarity in American designs. Both the older and newer models of the 911 use a flat-6, at first air cooled but later models are water-cooled. These automobiles situate the engine in the rear rather than the front, where its width does not interfere with the steering of the front wheels; the use of air-cooling obviates the need for connecting the engine to a radiator, and also reduces the weight even more. See also CPU cooling Watercooling Heat pipe cooling Peltier cooling External links http://www. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... The Volkswagen Beetle or Bug is a small family car, the best known car of Volkswagen, of Germany, and almost certainly the world. ... A flat-4 is a four cylinder internal combustion engine where the cylinders are arranged in a flat configuration, also referred to as horizontally opposed. ... This article is about the auto company. ... The Porsche 356 was a sports car produced from 1948 through 1965. ... The Porsche 912 is a sports car automobile manufactured by Porsche GmbH of Germany between 1965 and 1969 as an entry-level model. ... Corvair convertible The Chevrolet Corvair was an automobile produced by the Chevrolet division of General Motors from 1960 to 1969. ... The Corvairs innovative flat-6 engine The Chevrolet Corvair engine was a flat-6 piston engine used exclusively in the 1960s Chevrolet Corvair automobile. ... Porsche 911 in hillclimb The Porsche 911 (pronounced as nine eleven) is a sports car made by Porsche AG of Stuttgart, Germany. ... The flat-6 engine of the Honda Valkyrie motorcycle A flat-6 is a 6 cylinder configuration of a flat engine or boxer engine. ... Radiators and convectors are types of heat exchangers designed to transfer thermal energy from one medium to another for the purpose of cooling and heating. ...

Front-mounted air-cooled flat-twin engines were used by Citroën in their model 2CV and its derivatives, while the Citroën GS used a flat-4, and a flat-6 was proposed for the Citroën DS, but rejected. BMW uses an air-cooled flat-twin in many of their motorcycles. BMW motorcycle powered by a flat-twin engine A flat-twin is a two cylinder internal combustion engine where the cylinders are arranged in a flat configuration. ... Citroën is a French automobile manufacturer, founded in 1919 by André Citroën. ... First generation Ripple Bonnet Citroën 2CV built from 1948 to 1960 The Citroën 2CV (French: deux chevaux, literally two horses, from the tax horsepower rating) was an economy car produced by the French automaker Citroën from 1948 to 1990. ... 1970s GS Service Van The Citroën GS/GSA is a small family car produced by the French automaker Citroën between 1970 and 1986. ... A flat-4 is a four cylinder internal combustion engine where the cylinders are arranged in a flat configuration, also referred to as horizontally opposed. ... The flat-6 engine of the Honda Valkyrie motorcycle A flat-6 is a 6 cylinder configuration of a flat engine or boxer engine. ... 1974 Citroën DS23 Pallas Directional headlight detail of a Citroën DS21 Swedish-spec Citroën DS with headlight wipers Citroën DS Break - also known as the Safari, Familiale, or Wagon 1966 Citroën DS Convertible Turn indicators were mounted in the upper corners of the rear window... Bayerische Motoren Werke AG (BMW), is an independent German company and manufacturer of automobiles and motorcycles. ... MotorCycle is the title of a 1993 album by rock band Daniel Amos, released on BAI Records. ...

Boxer engines

A BMW "Boxer" twin motorcycle engine

Boxer engines probably got their name because the pistons of the motor, when observed from the top, resemble the fists of a boxer as he strikes them together before a bout.^{[citation needed]} Boxer engines of up to eight cylinders have proved highly successful in both automobiles and motorcycles, and continue to be popular for light aircraft engines. Image File history File linksMetadata Opposed-cylinders. ... Image File history File linksMetadata Opposed-cylinders. ... Car redirects here. ... General aviation (abbr. ...

One benefit of using a boxer engine versus a V-engine is that the design provides good balance because each piston's momentum is counterbalanced by the corresponding piston movement of the opposite side. Boxers are one of only four layouts that have a natural dynamic balance; the others being the straight-6, the flat-12 and the V12. These engines can run very smoothly and free of vibrations with a four-stroke cycle and do not require a balance shaft or counterweights on the crankshaft to balance the weight of the reciprocating parts, which are required in other engine configurations. (Note that this is true of all boxer engines regardless of the number of cylinders, but not true for all V, flat, and straight engines.) The straight-6 (also inline 6, I-6, or I6) is an internal combustion engine with six cylinders aligned in a single row. ... A flat-12 is an internal combustion engine in flat configuration, having 12 cylinders. ... Colombo Type 125 Testa Rossa engine in a 1961 Ferrari 250TR Spyder V-12 engine simplified cross-section V12 redirects here. ... Today Internal combustion engines in cars, trucks, motorcycles, construction machinery and many others, most commonly use a four-stroke cycle. ... Balance shaft in Ford Taunus V4 engine. ... Crankshaft (red), pistons (gray) in their cylinders (blue), and flywheel (black) Continental engine marine crankshafts, 1942 Components of a typical, four stroke cycle, DOHC piston engine. ...

Boxer engines tend to produce more noise than inline and V-engines because valve clatter is not so well dampened due to lack of covering by air-filters and other components, and produce a larger torsional vibration than a V-engine, and so, tend to require a larger flywheel. They have a characteristic smoothness throughout the rev range and, combined with the mounting position immediately ahead of the rear axle, offer a low center of gravity and more neutral handling.

Notable boxer engines

• In 1896, Karl Benz invented the first internal combustion engine with horizontally opposed pistons

1923 BMW R32 boxer engine

• In 1923 Max Friz designed the first BMW motorcycles, choosing a 500cc boxer engine and unit transmission with shaft drive
• The Volkswagen air-cooled flat-4 engine used in the Volkswagen Beetle, SP2 and Karmann Ghia, and later developed further for the Volkswagen Type 2(Bus) transporters and Volkswagen Type 3 cars
• The air-cooled flat-2 "foot-warmer" motorcycles produced for many years by BMW motorcycles, and as of 2005 now back in their range by popular demand after an attempt to discontinue the design
• The Citroën 2CV and Panhard air-cooled flat-2 engines, both influenced by the flat-2s of BMW
• The air-cooled Chevrolet Corvair flat-6
• The flat-4 engines in Alfa Romeo's Alfasud, Sprint, 33 and early versions of the 145 (last of the line was a 1712 cc flat four, 16 valves, producing up to 137bhp)
• The water-cooled front-mounted flat-4 and flat-6 engines used by Subaru in all of its mid-sized all wheel drive cars; Subaru refers to these as boxer engines in publicity commentary, and include a variety of naturally aspirated and turbo driven engines; in their turbo engines from 1984 to current, both closed and semi-closed short blocks have been used
• The water-cooled SOHC 1832cc flat-6 as fitted to the Honda Goldwing
• The air-cooled flat-4, flat-6, flat-8 and flat-12 engines were used for many years in early Porsches
• The water-cooled flat-6 engines in the Porsche Boxster, Cayman and later 911 models
• The engines of light private aircraft are often air-cooled flat-4s and flat-6s of the type famously made by the companies Lycoming, and Continental

Karl Benz Karl Friedrich Benz (November 25, 1844 – April 4, 1929) was a German engine designer and automobile engineer, generally regarded as the inventor of the gasoline-powered automobile. ... This article does not cite any references or sources. ... Image File history File linksMetadata R32-engine. ... Image File history File linksMetadata R32-engine. ... A 1924 BMW R32 at the 2006 BMW MOA international rally in Vermont. ... The Volkswagen air cooled engine is one of the most widely used and versatile internal combustion engines in the world. ... This article is about the original Volkswagen Beetle. ... A Service Pack (more commonly, SP) is a software program that corrects known bugs, problems, or adds new features. ... The Karmann Ghia is a two-seater sports car marketed by Volkswagen, designed by the Italian firm Ghia, and built by German coach builder Karmann. ... The Volkswagen Type 2 (aka Transporter) was the second automotive line introduced by German automaker Volkswagen. ... VW Type 3 Sedan (1966) The Volkswagen Type 3 was an automobile introduced in 1961 by Volkswagen to diversify its product range beyond the Type 1 (Beetle) and the Type 2 (Bus). ... BMW motorcycle powered by a flat-twin engine A flat-twin is a two cylinder internal combustion engine where the cylinders are arranged in a flat configuration. ... A 1924 BMW R32 at the 2006 BMW MOA international rally in Vermont. ... 2005 is a common year starting on Saturday of the Gregorian calendar. ... First generation Ripple Bonnet Citroën 2CV built from 1948 to 1960 The Citroën 2CV (French: deux chevaux, literally two horses, from the tax horsepower rating) was an economy car produced by the French automaker Citroën from 1948 to 1990. ... Corvair convertible The Chevrolet Corvair was an automobile produced by the Chevrolet division of General Motors from 1960 to 1969. ... The flat-6 engine of the Honda Valkyrie motorcycle A flat-6 is a 6 cylinder configuration of a flat engine or boxer engine. ... The Alfa Romeo Alfasud was a compact car made by Alfa Romeo of Italy from 1971 to 1989. ... The Alfa Romeo Sprint was a coupe version of the Alfa Romeo Alfasud, produced from 1976 to 1989 by Alfa Romeo. ... For other uses, see 33 (disambiguation). ... For other uses, see Subaru (disambiguation). ... Four wheel drive or 4x4, is a type of four wheeled vehicle drivetrain configuration that enables all four wheels to receive power from the engine simultaneously in order to provide maximum traction. ... The Honda Goldwing motorcycle had its debut in 1975, and became one of the most popular motorcycles in history. ... This article is about the auto company. ... The Porsche Boxster is a mid-engined roadster built by Porsche. ... The Porsche Cayman is a mid-engine 2-seat sports car launched in the 2006 model year. ... Porsche 911 in hillclimb The Porsche 911 (pronounced as nine eleven) is a sports car made by Porsche AG of Stuttgart, Germany. ... For other meanings of Lycoming, please see Lycoming (disambiguation). ... Continental Motors is a corporation in Mobile, Alabama, USA, that produces aircraft engines. ...

180° V-engines

Flat V engines are used in performance and racing cars, normally a 180 degree V12. Ferrari used a 180° version of the Colombo V12 in the Testarossa and Berlinetta Boxer models. A V engine is a common configuration for an internal combustion engine in which the pistons are aligned so that, if viewed along the line of the crankshaft, they appear to be in a V. Usually, two opposing pistons share one crank on the crankshaft. ... Ferrari Enzo. ... Ferraris earliest cars used engines designed by Gioacchino Colombo, who had formerly designed Alfa Romeos for Enzo Ferrari. ... A V12 is an internal combustion engine with 12 cylinders in V configuration. ... The Ferrari Testarossa is a 12-cylinder mid-engined sports car made by Ferrari, which went into production in 1984 as the successor to the Ferrari 512 Berlinetta Boxer. ... Berlinetta Boxer is the name for a series of cars produced by Ferrari in Italy between 1973 and 1984. ...

See also

Flat engine designs

• Flat-twin
• Flat-4
• Flat-6
• Flat-8
• Flat-10
• Flat-12
• Flat-16
• Controlled Combustion Engine

BMW motorcycle powered by a flat-twin engine A flat-twin is a two cylinder internal combustion engine where the cylinders are arranged in a flat configuration. ... A flat-4 is a four cylinder internal combustion engine where the cylinders are arranged in a flat configuration, also referred to as horizontally opposed. ... The flat-6 engine of the Honda Valkyrie motorcycle A flat-6 is a 6 cylinder configuration of a flat engine or boxer engine. ... A flat-8 is an internal combustion engine in flat configuration, having 8 cylinders. ... The flat 10 engine is an engine with two banks of five opposing cylinders each. ... A flat-12 is an internal combustion engine in flat configuration, having 12 cylinders. ... A flat-16 is an internal combustion engine in flat configuration, having 16 cylinders. ... Controlled Combustion Engine (CCE) is a type of internal combustion engine designed by Brad Howell-Smith in 1995. ...

Other engine designs

• X4 engine
• H engine
• V engine
• W engine
• Straight engine
• Rotary engine