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40-581: The Tapiro is powered by a longitudinally mounted, air-cooled 2.4-liter flat-six engine that produced 164 kW (220 hp; 217 PS) at 7,800 rpm, and is linked to a 5-speed manual transmission . This engine could propel the Tapiro to an official top speed of 152 mph (245 km/h). The Porsche Tapiro was introduced to the world at the 1970 Turin Auto Show , in Turin, Italy . The car made its US debut at

80-481: A rocking couple is present, since each cylinder is slightly offset from the other member of its pair due to the distance between the crankpins along the crankshaft. An alternative configuration for flat engines is as a 180-degree V engine , which has been used on most twelve-cylinder flat engines. In this configuration, each pair of pistons shares a crankpin , this being simpler than the boxer configuration, where each piston has its own separate crankpin. In 1902,

120-412: A closed circuit carrying liquid coolant through channels in the engine block and cylinder head. A fluid in these channels absorbs heat and then flows to a heat exchanger or radiator where the coolant releases heat into the air (or raw water , in the case of marine engines ). Thus, while they are not ultimately cooled by the liquid, as the heat is exchanged with some other fluid like air, because of

160-430: A fluid is a function of its capacity and the difference in input and output temperatures. As the boiling point of water is reduced with lower pressure, and the water could not be efficiently pumped as steam, radiators had to have enough cooling power to account for the loss in cooling power as the aircraft climbed. The resulting radiators were quite large and caused a significant amount of aerodynamic drag . This placed

200-486: A great percentage of the heat generated, around 44%, escapes through the exhaust. Another 8% or so ends up in the oil , which itself has to be cooled in an oil cooler . This means less than half of the heat has to be removed through other systems. In an air-cooled engine, only about 12% of the heat flows out through the metal fins. Air cooled engines usually run noisier, however it provides more simplicity which gives benefits when it comes to servicing and part replacement and

240-440: A horizontal fashion as a Flat engine , while vertical Straight-four engine have been used. Examples of past air-cooled road vehicles, in roughly chronological order, include: During the 1920s and 30s there was a great debate in the aviation industry about the merits of air-cooled vs. liquid-cooled designs. At the beginning of this period, the liquid used for cooling was water at ambient pressure. The amount of heat carried away by

280-499: A low centre of mass , low vibration, suitability for shaft drive, and equal cooling of the cylinders (for air-cooled engines). The most common design of flat engine for motorcycles is the boxer-twin, beginning with the 1905 Fée flat-twin engine, manufactured by the Light Motors Company, which was the first production motorcycle engine. BMW Motorrad have a long history of boxer-twin motorcycles, beginning in 1923 with

320-490: A rarity and V engines have almost vanished except in historical aircraft. They have even replaced radial engines in many smaller installations. The advantages of flat engines are a short length, low centre of mass and suitability for air cooling (due to the well-exposed, large-surface-area cylinders and cylinder heads, and their short length). Compared with the more common straight engines , flat engines have better primary balance (resulting in less vibration); however,

360-405: Is a piston engine where the cylinders are located on either side of a central crankshaft . Flat engines are also known as horizontally opposed engines , however this is distinct from the less common opposed-piston engine design, whereby each cylinder has two pistons sharing a central combustion chamber. The most common configuration of flat engines is the boxer engine configuration, in which

400-418: Is usually cheaper to be maintained. Many motorcycles use air cooling for the sake of reducing weight and complexity. Few current production automobiles have air-cooled engines (such as Tatra 815 ), but historically it was common for many high-volume vehicles. The orientation of the engine cylinders is commonly found in either single-cylinder or coupled in groups of two, and cylinders are commonly oriented in

440-539: The BMW R32 Several motorcycles have been produced with flat-four engines, such as the 1938–1939 Zündapp K800 and the 1974–1987 Honda Gold Wing . In 1987, the Honda Gold Wing engine was upsized to a flat-six design. When used in cars, advantages of flat engines are a low centre of mass (which improves the handling of the car), short length, low vibration and suitability for air cooling (due to

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480-487: The Subaru EE engine became the world's first passenger car diesel boxer engine. This engine is a turbocharged boxer-four with common rail fuel injection. Ferrari used flat-twelve engines for various Formula One cars in the 1970s. A road car flat-twelve engine (using a 180-degree V12 configuration) was used for the 1973-1984 Ferrari Berlinetta Boxer , 1984-1996 Ferrari Testarossa and their derivatives. Toyota uses

520-601: The Subaru Leone (1971–1994), Subaru Legacy (1989-present) and Subaru Impreza (1992–present). The front half-shafts come out of a front differential that is part of the gearbox. A rear driveshaft connects the gearbox to the rear half-shafts. The traditional front-engine, rear-wheel-drive layout is relatively uncommon for cars with flat engines, however some examples include the Toyota 86 / Subaru BRZ (2012–present), Jowett Javelin (1947–1953), Glas Isar (1958–1965) and

560-486: The Tatra 11 (1923–1927). The first flat engine was produced in 1897 by German engineer Karl Benz . Called the kontra engine, it was a boxer-twin design. Early uses of flat engines in cars include the 1900 Lanchester 8 hp Phaeton boxer-twin, the 1901 Wilson-Pilcher boxer-four, the 1904 Wilson-Pilcher 18/24 HP boxer-six and the 1903 Ford Model A , the 1904 Ford Model C and the 1905 Ford Model F . In 1938,

600-689: The Volkswagen Beetle (then called the "KdF-Wagen") was released with a rear-mounted flat-four engine. This Volkswagen air-cooled engine was produced for many years and also used in the Volkswagen Type 2 (Transporter, Kombi or Microbus), the Volkswagen Karmann Ghia sports car and the Volkswagen Type 3 compact car. A water-cooled version, known as the Wasserboxer , was introduced in 1982 and eventually replaced

640-621: The 1900s. The first commercial production was by the New Way Motor Company of Lansing, Michigan, US. The company produced air-cooled engines in single and twin cylinders in both horizontal and vertical cylinder format. Subsequent to their initial production which was exported worldwide, other companies took up the advantages of this cooling method, especially in small portable engines. Applications include mowers, generators, outboard motors, pump sets, saw benches and auxiliary power plants and more. Flat engine A flat engine

680-528: The 1930s and 1940s. During World War II, a boxer-twin engine called the "Riedel starter" was used as a starter motor/mechanical APU for the early German jet engines, such as the Junkers Jumo 004 and BMW 003 . Designed by Norbert Riedel , these engines have a very oversquare stroke ratio of 2:1 so that they could fit within the intake diverter, directly forward of the turbine compressor. Flat engines offer several advantages for motorcycles including

720-414: The 5th Annual Los Angeles Imported Automobile and Sports Car Show in 1971. In 1972, the car was sold to a Spanish industrialist who used it as his daily driver. The car was mostly destroyed after it caught fire. Most sources say the cause of the fire was a group of labor activists protesting its owner's labor policies, who planted a bomb under the Tapiro. The bomb exploded, burning the car but not destroying

760-690: The Light-Sport Aircraft ( LSA ) and ultralight aircraft market. Rotax uses a combination of air-cooled cylinders and liquid-cooled cylinder heads. Some small diesel engines, e.g. those made by Deutz AG and Lister Petter are air-cooled. Probably the only big Euro 5 truck air-cooled engine (V8 320 kW power 2100 N·m torque one) is being produced by Tatra . BOMAG part of the FAYAT group also utilizes an air cooled inline 6 cylinder motor, in many of their construction vehicles. Stationary or portable engines were commercially introduced early in

800-573: The Navy underwriting air-cooled engine development at Pratt & Whitney and Wright Aeronautical . Most other groups, especially in Europe where aircraft performance was rapidly improving, were more concerned with the issue of drag. While air-cooled designs were common on light aircraft and trainers, as well as some transport aircraft and bombers , liquid-cooled designs remained much more common for fighters and high-performance bombers. The drag issue

840-502: The Pearse monoplane (which would later become one of the first aircraft to achieve flight) was powered by a flat-twin engine. Amongst the first commercially-produced aircraft to use a flat engine was the 1909 Santos-Dumont Demoiselle range of aeroplanes, which was powered by boxer-twin engines. Several boxer-four engines have been produced specifically for light aircraft. A number of manufacturers produced boxer-six aircraft engines during

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880-446: The air-cooled versions. The majority of sports cars throughout Porsche's history are powered by flat engines, beginning with its first car; the 1948-1965 Porsche 356 used an air-cooled boxer-four engine. Also using boxer-four engines were the 1969-1976 Porsche 914 , the 1965-1969 Porsche 912 and the 2016-present Porsche Boxster/Cayman (982) . The Porsche 911 has exclusively used boxer-six engines from its introduction in 1964 until

920-417: The chassis. Other sources say the car was involved in an accident and caught fire that way. The burnt shell was repurchased by the engineering and design company Italdesign , and is now on display in its Giugiaro Museum. This article about a classic post-war automobile produced between 1945 and 1975 is a stub . You can help Misplaced Pages by expanding it . Air-cooled Air-cooled engines rely on

960-868: The circulation of air directly over heat dissipation fins or hot areas of the engine to cool them in order to keep the engine within operating temperatures. Air-cooled designs are far simpler than their liquid-cooled counterparts, which require a separate radiator , coolant reservoir, piping and pumps. Air-cooled engines are widely seen in applications where weight or simplicity is the primary goal. Their simplicity makes them suited for uses in small applications like chainsaws and lawn mowers , as well as small generators and similar roles. These qualities also make them highly suitable for aviation use, where they are widely used in general aviation aircraft and as auxiliary power units on larger aircraft. Their simplicity, in particular, also makes them common on motorcycles . Most modern internal combustion engines are cooled by

1000-472: The disadvantages are increased width and the need to have two cylinder heads. Compared with V engines – the most common layout for engines with six cylinders or more – flat engines again have a lower centre of mass, and, for six-cylinders, better primary balance; the disadvantage is again their being wider. The most common usages of flat engines are: Most flat engines use a "boxer" configuration, where each pair of opposing pistons move inwards and outwards at

1040-482: The first uses of a turbocharger in a mass-produced automobile. The Subaru EA engine was introduced in 1966 and began Subaru 's line of boxer-four engines that remain in production to this day. Most of Subaru's models are powered by a boxer-four engine in either naturally aspirated or turbocharged form. A print ad for the 1973 Subaru GL coupe referred to the engine as "quadrozontal". The company also produced boxer-six engines from 1988 to 1996 and 2001–2019. In 2008,

1080-575: The liquid-coolant circuit they are known as liquid-cooled . In contrast, heat generated by an air-cooled engine is released directly into the air. Typically this is facilitated with metal fins covering the outside of the Cylinder Head and cylinders which increase the surface area that air can act on. Air may be force fed with the use of a fan and shroud to achieve efficient cooling with high volumes of air or simply by natural air flow with well designed and angled fins. In all combustion engines,

1120-506: The much smaller radiators and less fluid in the system, the weight and drag of these designs was well below contemporary air-cooled designs. On a weight basis, these liquid-cooled designs offered as much as 30% better performance. In the late- and post-war era, the high-performance field quickly moved to jet engines . This took away the primary market for late-model liquid-cooled engines. Those roles that remained with piston power were mostly slower designs and civilian aircraft. In these roles,

1160-711: The pistons of each opposed pair of cylinders move inwards and outwards at the same time. The other configuration is effectively a V engine with a 180-degree angle between the cylinder banks: in this configuration each pair of cylinders shares a single crankpin, so that as one piston moves inward, the other moves outward. The first flat engine (Benz Contramotor) was built in 1897 by Karl Benz . Flat engines have been used in aviation, motorcycle and automobile applications. They are now less common in cars than straight engines (for engines with fewer than six cylinders) and V engines (for engines with six or more cylinders). Flat engines are more common in aircraft, where straight engines are

1200-615: The present. In 1997, the Porsche 911 switched from being air-cooled to water-cooled. Porsche flat-eight engines were used in various racing cars throughout the 1960s, such as the 1962 Porsche 804 Formula One car and the 1968-1971 Porsche 908 sports car. A flat-twelve engine was also produced by Porsche for the 1969-1973 Porsche 917 sports car. Chevrolet used a horizontally opposed air-cooled 6 cylinder engine in its Corvair line during its entire production run from 1960 to 1969 in various applications and power ratings, including one of

1240-529: The radiator size by 50% compared to water cooled designs. The experiments were extremely successful and by 1932 the company had switched all future designs to this coolant. At the time, Union Carbide held a monopoly on the industrial process to make glycol, so it was initially used only in the US, with Allison Engines picking it up soon after. It was not until the mid-1930s that Rolls-Royce adopted it as supplies improved, converting all of their engines to glycol. With

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1280-415: The same time, somewhat like boxing competitors punching their gloves together before a fight. Boxer engines have low vibration, being they are the only common configuration that has no unbalanced forces, regardless of the number of pairs of cylinders. Boxer engines therefore do not require either a balance shaft or counterweights on the crankshaft to balance the weight of the reciprocating parts. However,

1320-605: The short length of flat engines, locating a flat engine outside of the car's wheelbase results in minimal overhang. Therefore, many cars with flat engines have used a rear-engine, rear-wheel-drive layout . Examples include the flat-twin BMW 600 (1957–1959) and BMW 700 (1959–1965); the flat-four Tatra 97 (1936–1939), Volkswagen Beetle (1938–2003) and Porsche 356 (1948–1965); and the flat-six Chevrolet Corvair (1959–1969), Porsche 911 (1963-present), and Tucker 48 (1947–1948). The opposite layout, front-engine front-wheel drive ,

1360-454: The simplicity and reduction in servicing needs is far more important than drag, and from the end of the war on almost all piston aviation engines have been air-cooled, with few exceptions. As of 2020 , most of the engines manufactured by Lycoming and Continental are used by major manufacturers of light aircraft Cirrus , Cessna and so on. Other engine manufactures using air-cooled engine technology are ULPower and Jabiru , more active in

1400-458: The steam through tubes located just under the skin of the wings and fuselage, where the fast moving outside air condensed it back to water. While this concept was used on a number of record-setting aircraft in the late 1930s, it always proved impractical for production aircraft for a wide variety of reasons. In 1929, Curtiss began experiments replacing water with ethylene glycol in a Curtiss D-12 engine. Glycol could run up to 250 C and reduced

1440-459: The two designs roughly equal in terms of power to drag, but the air-cooled designs were almost always lighter and simpler. In 1921, the US Navy , largely due to the efforts of Commander Bruce G. Leighton , decided that the simplicity of the air-cooled design would result in less maintenance workload, which was paramount given the limited working area of aircraft carriers . Leighton's efforts led to

1480-590: The volume of water required and the size of the radiator by as much as 30%, which opened the way to a new generation of high-powered, relatively low-drag liquid cooled inline engines such as the Rolls-Royce Merlin and Daimler-Benz DB601 , which had an advantage over the unpressurized early versions of the Jumo 211 . This also led to development work attempting to eliminate the radiator entirely using evaporative cooling , allowing it to turn to steam and running

1520-478: The well exposed, large surface area, cylinder heads and short length). However the larger width of flat engines (compared with the more common inline and V layouts) is a drawback, particularly when the engine is located between the steered wheels. Flat engines were used by various automobile manufacturers – mostly with a boxer-four design – up until the late 1990s. Since then, only Porsche and Subaru have remained as significant manufacturers of flat engines. Due to

1560-457: Was also common for cars with flat engines. Examples include the Citroën 2CV (1948–1990), Panhard Dyna X (1948–1954), Lancia Flavia (1961–1970), Citroën GS (1970–1986), Alfa Romeo Alfasud (1971–1989) and Subaru Leone (1971–1994). Subaru have been producing cars with a front-engine, four-wheel-drive layout powered by flat engines (mostly boxer-four engines) since 1971. Examples include

1600-493: Was upset by the 1929 introduction of the NACA cowl , which greatly reduced the drag of air-cooled engines in spite of their larger frontal area, and the drag related to cooling was at this point largely even. In the late 1920s into the 1930s, a number of European companies introduced cooling system that kept the water under pressure allowed it to reach much higher temperatures without boiling, carrying away more heat and thus reducing

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