1.
Engineering
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The term Engineering is derived from the Latin ingenium, meaning cleverness and ingeniare, meaning to contrive, devise. Engineering has existed since ancient times as humans devised fundamental inventions such as the wedge, lever, wheel, each of these inventions is essentially consistent with the modern definition of engineering. The term engineering is derived from the engineer, which itself dates back to 1390 when an engineer originally referred to a constructor of military engines. In this context, now obsolete, a referred to a military machine. Notable examples of the obsolete usage which have survived to the present day are military engineering corps, the word engine itself is of even older origin, ultimately deriving from the Latin ingenium, meaning innate quality, especially mental power, hence a clever invention. The earliest civil engineer known by name is Imhotep, as one of the officials of the Pharaoh, Djosèr, he probably designed and supervised the construction of the Pyramid of Djoser at Saqqara in Egypt around 2630–2611 BC. Ancient Greece developed machines in both civilian and military domains, the Antikythera mechanism, the first known mechanical computer, and the mechanical inventions of Archimedes are examples of early mechanical engineering. In the Middle Ages, the trebuchet was developed, the first steam engine was built in 1698 by Thomas Savery. The development of this gave rise to the Industrial Revolution in the coming decades. With the rise of engineering as a profession in the 18th century, similarly, in addition to military and civil engineering, the fields then known as the mechanic arts became incorporated into engineering. The inventions of Thomas Newcomen and the Scottish engineer James Watt gave rise to mechanical engineering. The development of specialized machines and machine tools during the revolution led to the rapid growth of mechanical engineering both in its birthplace Britain and abroad. John Smeaton was the first self-proclaimed civil engineer and is regarded as the father of civil engineering. He was an English civil engineer responsible for the design of bridges, canals, harbours and he was also a capable mechanical engineer and an eminent physicist. Smeaton designed the third Eddystone Lighthouse where he pioneered the use of hydraulic lime and his lighthouse remained in use until 1877 and was dismantled and partially rebuilt at Plymouth Hoe where it is known as Smeatons Tower. The United States census of 1850 listed the occupation of engineer for the first time with a count of 2,000, there were fewer than 50 engineering graduates in the U. S. before 1865. In 1870 there were a dozen U. S. mechanical engineering graduates, in 1890 there were 6,000 engineers in civil, mining, mechanical and electrical. There was no chair of applied mechanism and applied mechanics established at Cambridge until 1875, the theoretical work of James Maxwell and Heinrich Hertz in the late 19th century gave rise to the field of electronics
2.
Internal combustion engine
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An internal combustion engine is a heat engine where 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 applied typically to pistons, turbine blades, rotor or a nozzle. This force moves the component over a distance, transforming chemical energy into mechanical energy. The first commercially successful internal combustion engine was created by Étienne Lenoir around 1859, firearms are also a form of internal combustion engine. Working fluids can be air, hot water, pressurized water or even liquid sodium, ICEs are usually powered by energy-dense fuels such as gasoline or diesel, liquids derived from fossil fuels. While there are many applications, most ICEs are used in mobile applications and are the dominant power supply for vehicles such as cars, aircraft. Typically an ICE is fed with fossil fuels like natural gas or petroleum products such as gasoline, there is a growing usage of renewable fuels like biodiesel for compression ignition engines and bioethanol or methanol for spark ignition engines. Hydrogen is sometimes used, and can be made from fossil fuels or renewable energy. Various scientists and engineers contributed to the development of internal combustion engines, in 1791, John Barber developed a turbine. In 1794 Thomas Mead patented a gas engine, also in 1794 Robert Street patented an internal combustion engine, which was also the first to use liquid fuel, and built an engine around that time. In 1798, John Stevens built the first American internal combustion engine, in 1807, Swiss engineer François Isaac de Rivaz built an internal combustion engine ignited by electric spark. In 1823, Samuel Brown patented the first internal combustion engine to be applied industrially, in 1860, Belgian Jean Joseph Etienne Lenoir produced a gas-fired internal combustion engine. In 1864, Nikolaus Otto patented the first atmospheric gas engine, in 1872, American George Brayton invented the first commercial liquid-fuelled internal combustion engine. In 1876, Nikolaus Otto, working with Gottlieb Daimler and Wilhelm Maybach, patented the compressed charge, in 1879, Karl Benz patented a reliable two-stroke gas engine. In 1892, Rudolf Diesel developed the first compressed charge, compression ignition engine, in 1926, Robert Goddard launched the first liquid-fueled rocket. In 1939, the Heinkel He 178 became the worlds first jet aircraft, at one time, the word engine meant any piece of machinery — a sense that persists in expressions such as siege engine. A motor is any machine that produces mechanical power, traditionally, electric motors are not referred to as Engines, however, combustion engines are often referred to as motors. In boating an internal combustion engine that is installed in the hull is referred to as an engine, reciprocating piston engines are by far the most common power source for land and water vehicles, including automobiles, motorcycles, ships and to a lesser extent, locomotives
3.
Opposed-piston engine
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An opposed-piston engine is a reciprocating internal combustion engine in which each cylinder has a piston at both ends, and no cylinder head. In 1882 James Atkinson developed the Atkinson cycle, a variant of the four stroke Otto cycle, the first implementation of this was arranged as an opposed piston engine, the Atkinson differential engine. Opposed piston engines using the two stroke cycle are known to have made by Oechelhäuser as early as 1898, when a 600 hp 2-stroke gas engine was installed at the Hoerde ironworks. These engines were made by Deutsche Kraftgas Gesellschaft from 1899, smaller versions of opposed piston engines suitable for motor vehicles probably begin with the French company Gobron-Brillié around 1900. The first diesel engine with opposed pistons, was a prototype built at the Kolomna plant in Russia, the designer, Raymond A. Koreyvo, patented the engine in France, on November 6,1907, then displayed the engine at international exhibitions. After these demonstrations similar engines were produced by other companies, Koreyvo filed a claim against these companies which was rejected by the Kolomna plant as the managing director did not want any quarrels with influential foreigners. In the USSR, the piston engine was used only after meetings with German aircraft makers, Junkers. In the USSR locomotive diesel engines adapted American Fairbanks-Morse designs and these engines were also used in military boats, set out under the world war two Lend-Lease contracts. Opposed piston engines should not be confused with flat engines, which are horizontally opposed with one piston per cylinder, some variations of the opposed piston or OP designs use a single crankshaft. The Gobron-Brillié, and Doxford ship engines used a crankshaft at one end of the cylinders, the crank throws for each end were often unequal giving a shorter motion for the end having the higher reciprocating weight in order to help balance. The Commer TS3 3-cylinder truck engines have a crankshaft beneath the centre of the cylinders with both pistons connected by levers. The levers operating the pistons allowed for a large piston travel with smaller crank throw, a more common layout uses two crankshafts, with the crankshafts geared together, or even three geared crankshafts in the Napier Deltic diesel engines. The Deltic uses three crankshafts, one at each corner, to form the three banks of double-ended cylinders arranged in an equilateral triangle and these were used in railway locomotives and to power fast patrol boats. Both types are now obsolete, although the Royal Navy still maintains some Deltic-powered Hunt-class mine countermeasure vessels. The first opposed-piston diesel engines were developed in the beginning of the 20th century, in 1907, Russian Raymond Koreyvo, the engineer of Kolomna Works, built an opposed-piston two-stroke diesel with two crankshafts connected by gearing. Although Koreyvo patented his engine in France in November 1907, the management would not go on to manufacture opposed-piston engines, the first Junkers engines had one crankshaft, the upper pistons having long connecting rods outside the cylinder. These engines were the forerunner of the Doxford marine engine, later engines, such as the Junkers Jumo 205 diesel aircraft engine and todays Achates Power engine, use two crankshafts, one at either end of a single bank of cylinders. There are efforts to reintroduce the opposed-piston diesel aircraft engine with twin geared crankshafts for general aviation applications, Fairbanks-Morse also used it in diesel locomotives starting in 1944
4.
Flat-four engine
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A flat-four or horizontally opposed-four is a type of four-cylinder engine, a flat engine with four cylinders arranged horizontally in two banks of two cylinders on each side of a central crankcase. The design is seen with shared crank throws, so flat-four and boxer-four are usually used synonymously. The configuration results in inherently good balance of the parts, a low centre of gravity. The layout also lends itself to efficient air cooling with excellent thermal balance, the low centre of gravity of the engine is an advantage. The shape of the engine suits it better for mid engine or rear engine designs, with a rear engine layout, it allows a low-tail body while in front engine designs the width of the engine often interferes with the maximum front wheel steering angle. Boxer engines tend to be better balanced than other four-cylinder configurations and this problem becomes worse with increased piston speed and weight, effectively limiting the capacity of these engines. Inline-fours larger than 2.0 L usually have balance shafts whilst engines over 3.0 L are seldom used in passenger cars. In contrast, the flat-four has much less secondary imbalance at the expense of larger rocking vibrations and this is because the cylinders cannot be directly opposed, but must be offset so the connecting rods can be on separate crank pins, which results in the forces being slightly off-centre. The rocking vibration is not serious enough to require balance shafts. As the firing order on an ordinary flat-four boxer engine on Left, by counting two characters to the right of each L or R, the cylinders that fire with 360 degree crankshaft rotational angle offset are shown to be located on opposite banks. As a result, most Subaru flat-four engines no longer have the flat-four burble, the Impreza WRX and WRX STI still have unequal length exhaust pipes to feed the turbo sitting in the corner of the engine bay, and still have the characteristic burble. This was changed for the 2015 WRX which feeds a centrally mounted turbo and they are, however, a somewhat popular aftermarket modification. In addition, four-stroke cycle flat-fours have a common to all four-cylinder engines. This results in gaps between strokes and a pulsating delivery of torque to the flywheel, causing a rotational vibration on the entire engine along the crankshaft axis. By contrast, in engines with more cylinders the power strokes overlap, the piston starts its power stroke before the previous one has finished. Luxury performance car manufacturers prefer to use the inline-six, flat-six, or V8 configurations because these designs are much smoother than the flat-four, in 1897 Karl Benz developed the boxer engine. This drive system, in two horizontally opposed cylinders turned a single crankshaft, was given the name “contra engine”. The unit was used from 1899 onwards, principally in passenger, the final evolutionary stage of the Benz racing car equipped with a contra engine was the 20-hp Benz vehicle introduced in 1900
5.
Flat-six engine
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A flat-6 or horizontally opposed-6 is a flat engine with six cylinders arranged horizontally in two banks of three cylinders on each side of a central crankcase. This should not be confused with the Opposed-piston engine, the configuration results in inherently good balance of the reciprocating parts, a low center of gravity, and a very short engine length. The layout also lends itself to air cooling. Only a few auto makers, including Porsche and Subaru, currently use horizontally opposed engines, in the past a number of other manufacturers have used them, notably Preston Tucker in the 1948 Tucker Sedan and Chevrolet in the 1960s Corvair with flat-6 air-cooled engines. The Citroën DS was originally intended to be fitted with an air-cooled flat-6, unlike the V6 but like the inline-6, the flat-6 is a fully balanced configuration which is in perfect primary and secondary balance. The flat-6 is also smoother than the flat-4 or inline-4 because the strokes of the cylinders overlap in a four-stroke cycle engine. In the flat-6, each power stroke begins 120 degrees after the previous one starts, Lycoming is a major US manufacturer of civilian aircraft engines that power over one half of General aviation aircraft. They have developed and currently produce a series of flat-4 and flat-6 aircraft engines, the configuration is expressed in the engines model numbers as the letter O, standing for opposed in reference to the cylinder arrangement. Franklin produced horizontally opposed aircraft engines beginning in the 1930s. The Franklin O-335 was used in Bell 47, Continental Motors produces flat-4 and flat-6 aircraft engines which began in 1931 with the Continental A-40. Flat engines largely replaced the more popular radial engines in small aircraft after World War II because they were less expensive to manufacture. Radial engines have inherently good cooling, but their large frontal area increases drag and it is not difficult to design flat-6 and flat-8 engines from flat-4 designs by adding more cylinder pairs with a new crankshaft. In an air-cooled engine there can be cooling problems with the middle cylinder pairs, the flat-6 is smoother running than a flat-4 design. Possibly the earliest flat-six engined car was the Wilson-Pilcher car in 1900, the engine was conventionally placed with the crankshaft in-line with the chassis and the cylinders between the chassis rails. Reports on this car quote it as being silent and smooth running. The car was produced by Wilson-Pilcher in London until 1904, then by Armstrong Whitworth & Co in Newcastle until c1907. The engine had equal bore and stroke of 95mm, and the cylinders were offset so that each cylinder had its own crank-pin. The engine was mounted to a 4-speed epicyclic gearbox employing helical gears in an oil bath
6.
Subaru
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Subaru is the automobile manufacturing division of Japanese transportation conglomerate Subaru Corporation, the twenty-second largest automaker by production worldwide in 2012. Subaru cars are known for the use of a boxer engine layout in most vehicles above 1500 cc, most Subaru models have used the Symmetrical All Wheel Drive drive-train layout since 1972. The lone exception is the BRZ, introduced in 2012, which uses the boxer engine, Subaru also offers turbocharged versions of their passenger cars, such as the Impreza WRX and the Legacy 2. 5GT. The 2. 5XT trims of the Outback and Forester also include a turbocharged engine, in Western markets, the Subaru brand has traditionally been popular among a dedicated core of buyers. Marketing is targeted towards specific niches centered on those who desire the companys signature drive train, in particular the outdoors enthusiast and affordable sports car markets. Subaru is the Japanese name for the Pleiades star cluster M45, or The Seven Sisters, Fuji Heavy Industries started out as The Aircraft Research Laboratory in 1915, headed by Chikuhei Nakajima. In 1932, the company was reorganized as Nakajima Aircraft Company, Ltd, at the end of the Second World War Nakajima Aircraft was again reorganized, this time as Fuji Sangyo Co, Ltd. In 1946, the created the Fuji Rabbit motor scooter with spare aircraft parts from the war. In 1950, Fuji Sangyo was divided into 12 smaller corporations according to the Japanese Governments 1950 Corporate Credit Rearrangement Act, between 1953 and 1955, four of these corporations and a newly formed corporation decided to merge to form Fuji Heavy Industries. Kenji Kita, CEO of Fuji Heavy Industries at the time, wanted the new company to be involved in car manufacturing, mr. Kita canvassed the company for suggestions about naming the P1, but none of the proposals was appealing enough. In the end he gave the company a Japanese name that he had been cherishing in his heart, Subaru, the first Subaru car was named the Subaru 1500. Only twenty were manufactured owing to supply issues. Subsequently, the designed and manufactured dozens of vehicles including the 1500, the tiny air-cooled 360, the Sambar. Nissan would utilize FHIs bus manufacturing capability and expertise for their Nissan Diesel line of buses, in turn many Subaru vehicles, even today, use parts from the Nissan manufacturing keiretsu. The Subaru automatic transmission, known as the 4EAT, is used in the first generation Nissan Pathfinder. While under this arrangement with Nissan, Subaru introduced the R-2, the Rex and the Leone, the BRAT, Alcyone, the Legacy, the Impreza, upon Nissans acquisition by Renault, its stake in FHI was sold to General Motors in 1999. Troy Clarke, of General Motors served as representative to Fuji Heavy Industries on their corporate board, during that time, Subaru introduced the Baja, and the Tribeca. The Subaru Forester was sold as a Chevrolet Forester in India in exchange for the Opel Zafira being sold as a Subaru Traviq in Japan, also, the Chevrolet Borrego concept was presented in 2002, a crossover coupe/pickup truck being derived from the Japanese-market Legacy Turbo platform
7.
H engine
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An H engine is an engine configuration in which the cylinders are aligned so that if viewed from the front, they appear to be in a vertical or horizontal letter H. An H engine can be viewed as two engines, one atop or beside the other. The two engines each have their own crankshaft, which are geared together at one end for power-take-off. The H configuration allows the building of multi-cylinder engines that are shorter than the alternatives, sometimes delivering advantages on aircraft, the power-to-weight ratio is not as good as simpler configurations employing one crankshaft. There is excellent mechanical balance, especially desirable and otherwise difficult to achieve in a four-cylinder engine, two straight engines can be similarly joined to provide a U engine. Lycoming Lycoming H-2470 H-24 hyper engine Fairey Aviation Fairey Prince -1,500 hp Fairey Monarch - H-242,240 hp Klöckner-Humboldt-Deutz DZ720 - H-32,102.9 litres D. Napier & Son, UK. The British Racing Motors H-16 Formula One engine won the 1966 US Grand Prix with Jim Clark in a Lotus 43, the Brough Superior Golden Dream motorcycle, first shown in 1938. A1,000 cc H-4 design and a few units were produced in early 1939, any development planned was interrupted by World War II and subsequent years of austerity. This was replaced by a flat-four engined prototype at the 1953 show, german firm Konig, who specialised in racing outboard motors, built a few 1000cc H-8s c. 1970s, which were two of their VC500 flat fours mounted one above the other, with the direction of rotation reversed on one of them. Both cylinders at each end of each engine fired at the same time, at least one H-8 found its way into a motorcycle & sidecar racing combo. Subaru produces water-cooled flat-four and flat-six Horizontally-opposed engines that are marketed as H4, the naming scheme refers to engine description, similar to inline engines being named I4 or I6, rather than their appearance front-on
8.
Multi-cylinder engine
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For multiple-cylinder steam engines, see Compound steam engine and Triple-expansion steam engine A multi-cylinder engine is a reciprocating internal combustion engine with multiple cylinders. It can be either a 2-stroke or 4-stroke engine, and can be either Diesel or spark-ignition, the cylinders and the crankshaft which is driven by and co-ordinates the motion of the pistons can be configured in a wide variety of ways. Typically, the more cylinders an engine has, the higher the RPMs it can attain for a displacement and technology level, at a cost of increased friction losses. Peak torque is reduced, but the total horsepower is increased due to the higher RPMs attained. Although there are 1,3 and 5-cylinder engines, almost all other engines are built with even numbers of cylinders. Another form of internal combustion engine is the radial engine. Twin-row or multi-row radials are also built, which is two or more single-row radials connected front-to-back and driving a common crankshaft. In this twin row, or multi-row configuration, the number of cylinders will be an even number. For example, a single row radial such as the Wright Cyclone has 9 cylinders. The twin row Wright Twin Cyclone is based on this engine, configurations of two-cylinder engines include, Straight-twin engine, or parallel twin with two cylinders in parallel sharing a crankshaft. V-twin engine, or V2 engine, two cylinders in V configuration, sharing a crankshaft, flat-twin engine, a flat engine with 2 opposed cylinders on the same crankshaft angled 180° to each other. Configurations of three-cylinder engines include, Straight-three engine, also called the inline-triple, inline-3, or I-3 engine, v3 engine, seen on some two-stroke racing motorcycles. W engine with three cylinders, such as the Anzani 3-cylinder fan engines, configurations of four-cylinder engines include, the most common 4-cylinder engine Inline-four engine, an engine with 4 cylinders in a straight line. V4 engine, an engine with 4 cylinders arranged in a V configuration, flat-four engine, a flat engine with 4 cylinders horizontally opposed to each other at 180° apart. Square four engine, two banks of 2 cylinders, each driving a single crankshaft and geared to an output shaft. Configurations of five-cylinder engines include, Straight-five engine, an engine with 5 cylinders in a straight line, vR5 engine, an engine with 5 cylinders staggered slightly, allowing cylinder bore centerlines to be closer together, reducing overall engine length. Configurations of six-cylinder engines include, V6 engine, a V engine with six cylinders, vR6 engine, a compromise between a V6 and straight-6 engine, shorter than a straight-6 and narrower than a V-6. Straight-six engine, an engine with six cylinders aligned in a straight line, flat-six engine, a flat engine with two banks of 3 cylinders horizontally opposed at 180° apart
9.
Inline engine (aeronautics)
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Straight or Inline Engines with a single bank of cylinders which can be arranged at any angle but typically upright or inverted. V Engines with two banks of cylinders with less than 180° between them driving a common crankshaft, typically arranged upright or inverted, W Engines with three banks driving a common crankshaft, arranged so that first and last banks are 180°or less apart. X Multiple bank engines with four arranged around a common crankshaft. Fan Engines with more than three banks with 180° or less between first and last bank, akin to W engines, note, Fan engines with single cylinder banks, typically from Anzani, are usually regarded as variants of the Radial engine. U Engines with two banks of cylinders side by side driving separate crankshafts geared to a single output, H Engines with four banks of cylinders driving two crankshafts geared to a single output, in effect, two Opposed engines coupled together and mounted either horizontally or vertically. Multiple bank Engines with more than two banks, arranged around a common axis and/or crankshaft with more than 180° between first and last banks. Star, Multiple bank engines with an number of banks arranged around a common axis and/or driving a common crankshaft with more than 180° between first and last banks
10.
Radial engine
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The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders radiate outward from a central crankcase like the spokes of a wheel. It resembles a star when viewed from the front, and is called a star engine in some languages. The radial configuration was very commonly used for aircraft engines before gas turbine engines became predominant, instead, the pistons are connected to the crankshaft with a master-and-articulating-rod assembly. One piston, the uppermost one in the animation, has a rod with a direct attachment to the crankshaft. The remaining pistons pin their connecting rods attachments to rings around the edge of the master rod, extra rows of radial cylinders can be added in order to increase the capacity of the engine without adding to its diameter. Four-stroke radials have an odd number of cylinders per row, so that a consistent every-other-piston firing order can be maintained, for example, on a five-cylinder engine the firing order is 1,3,5,2,4 and back to cylinder 1. Moreover, this leaves a one-piston gap between the piston on its combustion stroke and the piston on compression. The active stroke directly helps compress the next cylinder to fire, if an even number of cylinders were used, an equally timed firing cycle would not be feasible. The radial engine normally uses fewer cam lobes than other types, as with most four-strokes, the crankshaft takes two revolutions to complete the four strokes of each piston. The camshaft ring is geared to spin slower and in the direction to the crankshaft. The cam lobes are placed in two rows for the intake and exhaust, for the example, four cam lobes serve all five cylinders, whereas 10 would be required for a typical inline engine with the same number of cylinders and valves. C. M. Manly constructed a water-cooled five-cylinder radial engine in 1901, manlys engine produced 52 hp at 950 rpm. This was installed in his triplane and made a number of short free-flight hops, another early radial engine was the three-cylinder Anzani, originally built as a W3 fan configuration, one of which powered Louis Blériots Blériot XI across the English Channel. Georges Canton and Pierre Unné patented the engine design in 1909, offering it to the Salmson company. It was similar in concept to the radial, the main difference being that the propeller was bolted to the engine. The problem of the cooling of the cylinders, a factor with the early stationary radials, was alleviated by the engine generating its own cooling airflow. Most German aircraft of the time used water-cooled inline 6-cylinder engines, in the early 1920s Le Rhône converted a number of their rotary engines into stationary radial engines. By 1918 the potential advantages of air-cooled radials over the inline engine
11.
Rotary engine
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Its main application was in aviation, although it also saw use before its primary aviation role, in a few early motorcycles and automobiles. This type of engine was used as an alternative to conventional inline engines during World War I. It has been described as an efficient solution to the problems of power output, weight. The rotating mass of the engine also caused significant gyroscopic precession, depending on the type of aircraft, in the most common form, the crankshaft was fixed solidly to the airframe, and the propeller was simply bolted to the front of the crankcase. Improved cooling, when the engine was running the rotating crankcase/cylinder assembly created its own fast-moving cooling airflow, weight advantage, many conventional engines had to have heavy flywheels added to smooth out power impulses and reduce vibration. Rotary engines gained a substantial power-to-weight ratio advantage by having no need for an added flywheel, like radial engines, rotaries were generally built with an odd number of cylinders, so that a consistent every-other-piston firing order could be maintained, to provide smooth running. Rotary engines with an number of cylinders were mostly of the two row type. Rotary and radial engines look strikingly similar when they are not running and can easily be confused, unlike the rotary engine, however, radial engines use a conventional rotating crankshaft in a fixed engine block. The Musee de lAir in Paris has on display a special and it alternates between rotary and radial modes to demonstrate the difference between the internal motions of the two types of engine. It is often asserted that rotary engines had no carburetor and hence power could only be reduced by cutting the ignition using a blip switch. This was almost literally true of the Monosoupape type, which took most of the air into the cylinder through the exhaust valve, thus the richness of the mixture in the cylinder could not be controlled via the crankcase intake. The throttle of a monosoupape provided only a limited degree of speed regulation, as opening it made the mixture too rich. Early models featured a form of variable valve timing in an attempt to give greater control. Most rotaries however, had normal inlet valves, so that the fuel was taken into the already mixed with air - as in a normal four-stroke engine. The pilot needed to set the throttle to the desired setting, after starting the engine with a known setting that allowed it to idle, the air valve was opened until maximum engine speed was obtained. Throttling a running back to reduce revs was possible by closing off the fuel valve to the required position while re-adjusting the fuel/air mixture to suit. This process was also tricky, so that throttling back, especially when landing, was accomplished by intermittently cutting the ignition using the blip switch. Cutting cylinders using ignition switches had the drawback of letting fuel continue to pass through the engine, oiling up the spark plugs, also, the raw oil-fuel mix could collect in the cowling
12.
Wankel engine
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The Wankel engine is a type of internal combustion engine using an eccentric rotary design to convert pressure into rotating motion. The engine is referred to as a rotary engine, although this name applies also to other completely different designs. All parts rotate moving in one direction, as opposed to the reciprocating piston engine which has pistons violently changing direction. The design was conceived by German engineer Felix Wankel, Wankel received his first patent for the engine in 1929. He began development in the early 1950s at NSU, and completed a prototype in 1957. NSU subsequently licensed the design to companies around the world, who have continually added improvements, the engines produced are of spark ignition, with compression ignition engines only in research projects. The Wankel engine has the advantages of compact design and low weight over the most commonly used internal combustion engine employing reciprocating pistons, the point of power to weight has been reached of under one pound weight per horsepower output. In 1951, NSU Motorenwerke AG in Germany began development of the engine, the first, the DKM motor, was developed by Felix Wankel. The second, the KKM motor, developed by Hanns Dieter Paschke, was adopted as the basis of the modern Wankel engine, so the Wankel engine design used today was not designed by Felix Wankel, and the Paschke engine could be a more apt title. The basis of the DKM type of motor was that both the rotor and the housing spun around on separate axes, the DKM motor reached higher revolutions per minute and was more naturally balanced. However, the engine needed to be stripped to change the spark plugs, the KKM engine was simpler, having a fixed housing. The first working prototype, DKM54, produced 21 hp and ran on February 1,1957, at the NSU research and development department Versuchsabteilung TX. The KKM57 was constructed by NSU engineer Hanns Dieter Paschke in 1957 without the knowledge of Felix Wankel, in 1960, NSU, the firm that employed the two inventors, and the US firm Curtiss-Wright, signed a joint agreement. Curtiss-Wright recruited Max Bentele to head their design team, many manufacturers signed license agreements for development, attracted by the smoothness, quiet running, and reliability emanating from the uncomplicated design. Amongst them were Alfa Romeo, American Motors, Citroen, Ford, General Motors, Mazda, Mercedes-Benz, Nissan, Porsche, Rolls-Royce, Suzuki, in the United States in 1959, under license from NSU, Curtiss-Wright pioneered improvements in the basic engine design. In Britain, in the 1960s, Rolls Royces Motor Car Division pioneered a two-stage diesel version of the Wankel engine, Citroën did much research, producing the M35, GS Birotor and RE-2 Helicopter using engines produced by Comotor, a joint venture of Citroën and NSU. General Motors seemed to have concluded the Wankel engine was more expensive to build than an equivalent reciprocating engine. General Motors claimed to have solved the fuel issue
