The intake/inlet over exhaust , or "IOE" engine, known in the US as F-head , is a four-stroke internal combustion engine whose valvetrain comprises OHV inlet valves within the cylinder head and exhaust side-valves within the engine block.
94-538: IOE engines were widely used in early motorcycles , initially with the inlet valve being operated by engine suction instead of a cam-activated valvetrain. When the suction-operated inlet valves reached their limits as engine speeds increased, the manufacturers modified the designs by adding a mechanical valvetrain for the inlet valve. A few automobile manufacturers, including Willys , Rolls-Royce and Humber also made IOE engines for both cars and military vehicles. Rover manufactured inline four and six cylinder engines with
188-418: A manual five- or six-speed sequential transmission drives the swingarm -mounted rear wheel by a chain , driveshaft , or belt . The repair can be done using a Motorcycle lift . Motorcycle fuel economy varies greatly with engine displacement and riding style. A streamlined, fully faired Matzu Matsuzawa Honda XL125 achieved 470 mpg ‑US (0.50 L/100 km; 560 mpg ‑imp ) in
282-588: A trike ) is a two or three-wheeled motor vehicle steered by a handlebar from a saddle-style seat. Motorcycle designs vary greatly to suit a range of different purposes: long-distance travel, commuting , cruising , sport (including racing ), and off-road riding. Motorcycling is riding a motorcycle and being involved in other related social activities such as joining a motorcycle club and attending motorcycle rallies . The 1885 Daimler Reitwagen made by Gottlieb Daimler and Wilhelm Maybach in Germany
376-458: A DOHC 426 Hemi was in the works, it was banned from NASCAR races, though allowed in certain drag racing classes. Later Ford engine designs with hemispherical chambers included the Calliope , which used two in-block cams, arranged one over the other, to drive 3 valves per hemispherical chamber. The pushrods activating the valves from the top camshaft were almost horizontal. In 1968, Ford brought out
470-408: A cam-in-head configuration that allowed hemispherical arranged valves to be operated by a single camshaft and without the need for two rocker shafts. Although a wedge-head design offers simplified valve actuation, it usually does so by placing the valves side by side within the chamber, with parallel stem axes. This can restrict the flow of the intake and exhaust into and out of the chamber by limiting
564-507: A claimed 175 , was used by BMC in the Vanden Plas Princess 4-litre R saloon car. Over 6000 of these cars were made. Some engines have been made with the reverse configuration, having the exhaust valve located in the cylinder head and the intake valve in the block. The ABC Skootamota began production with an engine of this configuration, but this was changed to an overhead valve engine before production ended. In 1936 and 1937,
658-429: A combustion chamber of more complex shape than that of an overhead valve engine, which affects combustion rates and can create hot spots in the piston head, and inferior valve location, which hinders efficient scavenging. Due to the added complications of rocker arms and pushrods, it is also more complex and expensive to make than a sidevalve engine, as well as being physically larger due to the rocker arms being placed over
752-462: A comparable wedge head according to Chrysler 's engineers ). These had pushed the hemi head out of favor in the modern era, until Chrysler's 2003 redesign that has proven popular. SOHC Cutaway showing cross-flow design, hemispherical shape of the chamber, center position of the overhead cam with flanking supports for the rocker shafts. The hemi engine requires parts of more complexity and quantities. Upper photos of double rocker system for
846-789: A full motorcycle licence or endorsement for completing a Motorcycle Safety course varies by province. Without the Motorcycle Safety Course the chance of getting insurance for the motorcycle is very low. The Canada Safety Council , a non-profit safety organisation, offers the Gearing Up program across Canada and is endorsed by the Motorcycle and Moped Industry Council. Training course graduates may qualify for reduced insurance premiums. Motorcyclists and motor scooter riders are also exposed to an increased risk of suffering hearing damage such as hearing loss and tinnitus (ringing ears). The noise
940-499: A higher mechanical compression ratio, which tend to increase the flame propagation distance, being also detrimental to efficient combustion, unless the number of spark plugs per cylinder is increased. Flame temperatures are very high, leading to excessive NOx output which may require exhaust gas recirculation and other emission control measures to meet modern standards. Other drawbacks of the hemispherical chamber include increased production cost and high relative weight (25% heavier than
1034-486: A less diluted or muddied engine sound, allowing Alfa Romeo to use quieter stock exhausts without losing much of their distinct and beloved race-bred engine noise. Aston Martin 's DOHC V8 used a hemispherical chamber during the late 1960s through to the late 1980s. Each of four cams controlled one set of valves per cylinder bank. The Aston Martin V8 5.3 L (5340 cc/325 in ) produced 315 hp (235 kW) gross. BMW became
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#17328686979121128-654: A motorcycle ( German : Motorrad ). Excelsior Motor Company , originally a bicycle manufacturing company based in Coventry , England , began production of their first motorcycle model in 1896. The first production motorcycle in the US was the Orient-Aster, built by Charles Metz in 1898 at his factory in Waltham, Massachusetts . In the early period of motorcycle history, many producers of bicycles adapted their designs to accommodate
1222-414: A motorcycle either as OEM (factory-fitted) or aftermarket . Such accessories are selected by the owner to enhance the motorcycle's appearance, safety, performance, or comfort, and may include anything from mobile electronics to sidecars and trailers . Motorcycles have a higher rate of fatal accidents than automobiles or trucks and buses. United States Department of Transportation data for 2005 from
1316-509: A pair of Hemi heads and its complex piston casting. Lower photos of comparable parts for a pair of Wedge Heads. A major drawback of the hemi design is its large head size relative to overall engine size. The splayed valves necessary for the crossflow head require a wider casting, which requires large engine bays. Engineers are looking to reduce the physical size of engines (while maintaining or increasing their power). Alfa Romeo has produced successful hemi-head engines throughout
1410-535: A particularly efficient version of the IOE induction system. A few designs with the reverse system, exhaust over inlet (EOI), have been manufactured, such as the Ford Quadricycle of 1896. In a F-head/IOE engine, the intake manifold and its valves are located in the cylinder head above the cylinders, and are operated by rocker arms which reverse the motion of the pushrods so that the intake valves open downward into
1504-548: A particularly long career. After being used in Rover P4 saloon cars it was added to long-wheelbase Land Rover models from 1963 in the 2A Forward Control models, then in 1967 in the bonneted 109", and remained an optional fitment until 1980 when it was replaced by the Rover V8 . The shape of the combustion chamber as an "inverted hemi-head", along with the angled cylinder head joint and pitched-roof piston crowns, had earlier been used in
1598-419: A pocket, leading to the term "pocket valve" being used for IOE engines. An F-head engine combines features from both overhead-valve and flathead type engines, the inlet valve operating via pushrod and rocker arm and opening downward like an overhead valve engine, while the exhaust valve is offset from the cylinder and opens upward via an integrated pushrod/valve stem directly actuated by the camshaft, much like
1692-402: A role in how a motorcycle performs in given conditions. For example, one with a longer wheelbase provides the feeling of more stability by responding less to disturbances. Motorcycle tyres have a large influence over handling. Motorcycles must be leaned in order to make turns. This lean is induced by the method known as countersteering , in which the rider momentarily steers the handlebars in
1786-637: A small bore engine, allowing better breathing and better performance. The Rover IOE engine family encompassed straight-4 (1.6- and 2.0-litres) and straight-6 (2.1-, 2.2-, 2.3-, 2.4-, 2.6- and 3.0-litres) engines and powered much of the company's post-war range in the form of the P3 , P4 and P5 models. Adapted versions of the 1.6 and 2.0 IOE engines were used in early version of the Land Rover as well. Power outputs ranged from 50bhp (Land Rover 1.6) to 134bhp ( P5 3 litre MkII & III). The 2.6 6-cylinder IOE engine had
1880-568: A true hemispherical head. In 1964 Ford produced a single overhead cam 425 cu in FE-based hemi V8 known as the "427 SOHC "Cammer" ". Designed in 90 days of intensive engineering effort for use in racing, it never appeared in a production Ford vehicle, instead being sold as an optional engine at Ford parts counters. Period dynamometer results claim the SOHC Hemi produced almost 700 hp (522 kW) in crate form (100 hp per liter). It used
1974-535: A worldwide marque on the strength of its responsive yet durable SOHC hemi-head inline-4 M10 engine, most famously made in a 2 L (122 cu in) displacement in its 2002 sports sedan of the 1960s and 1970s. Perhaps the most widely known proponent of the hemispherical chamber design is the Chrysler Corporation . Chrysler became identified primarily by trademarking the "Hemi" name and then using it extensively in their advertising campaigns beginning in
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#17328686979122068-488: Is 43.47 which is 28 times higher than for cars (37 times more deaths per mile travelled in 2007). Furthermore, for motorcycles the accident rates have increased significantly since the end of the 1990s, while the rates have dropped for passenger cars. The most common configuration of motorcycle accidents in the United States is when a motorist pulls out or turns in front of a motorcyclist, violating their right-of-way. This
2162-604: Is a combustion chamber in the cylinder head of an internal combustion engine with a domed " hemispheric " shape. An engine featuring this type of hemispherical chamber is known as a hemi engine . In practice, shapes less than a full hemisphere are typically employed, as are variations (or faceting in parts) of a true hemispheric profile. The primary advantage of such shapes are increased compression (leading to greater power) and very large intake and exhaust valves (allowing better flow of intake and exhaust gasses, also resulting in improved volumetric efficiency and greater power);
2256-439: Is caused by wind noise while riding, rolling noise from the tyres and the engine itself. The helmet only provides insufficient protection against high sound pressure levels. Medicine (as of 2024) is not able to cure hearing damage. Wearing hearing protection, such as special earplugs for motorcyclists, can help prevent hearing damage. The motorcyclist's riding position depends on rider body-geometry ( anthropometry ) combined with
2350-593: Is increasingly problematic. The first (petroleum fueled) internal-combustion motorcycles, like the German Reitwagen , were, however, also the first practical motorcycles. If a two-wheeled vehicle with steam propulsion is considered a motorcycle, then the first motorcycles built seem to be the French Michaux-Perreaux steam velocipede which patent application was filed in December 1868, constructed around
2444-610: Is necessary to pass the basic motorcycle licence test. These include the Institute of Advanced Motorists (IAM) and the Royal Society for the Prevention of Accidents (RoSPA). Along with increased personal safety, riders with these advanced qualifications may benefit from reduced insurance costs In South Africa, the Think Bike campaign is dedicated to increasing both motorcycle safety and
2538-493: Is often a racing counterpart to each type, such as road racing and street bikes, or motocross including dirt bikes. Street bikes include cruisers , sportbikes , scooters and mopeds , and many other types. Off-road motorcycles include many types designed for dirt-oriented racing classes such as motocross and are not street legal in most areas. Dual purpose machines like the dual-sport style are made to go off-road but include features to make them legal and comfortable on
2632-477: Is sometimes called a SMIDSY , an acronym formed from the motorists' common response of "Sorry mate, I didn't see you". Motorcyclists can anticipate and avoid some of these crashes with proper training, increasing their visibility to other traffic, keeping to the speed limits, and not consuming alcohol or other drugs before riding. The United Kingdom has several organisations dedicated to improving motorcycle safety by providing advanced rider training beyond what
2726-483: Is the 1958 Honda Super Cub , which went on to become the biggest selling vehicle of all time, with its 60 millionth unit produced in April 2008. Today, this area is dominated by mostly Indian companies with Hero MotoCorp emerging as the world's largest manufacturer of two wheelers. Its Splendor model has sold more than 8.5 million to date. Other major producers are Bajaj and TVS Motors . Motorcycle construction
2820-585: Is the engineering, manufacturing, and assembly of components and systems for a motorcycle which results in the performance, cost, and aesthetics desired by the designer. With some exceptions, construction of modern mass-produced motorcycles has standardised on a steel or aluminium frame , telescopic forks holding the front wheel, and disc brakes . Some other body parts, designed for either aesthetic or performance reasons may be added. A petrol-powered engine typically consisting of between one and four cylinders (and less commonly, up to eight cylinders) coupled to
2914-650: The 'Orion' , 'Astron' , and 'Saturn' units. Nissan's Z , VG (SOHC version only) and DOHC VQ engines use hemispherical combustion chambers. The Z and VG are true hemispherical while the VQ uses a compound pent-roof shape. Porsche has made extensive use of hemi-head engines , including the air-cooled flat-6 engine in Porsche 911 models from 1963 to 1999. The 1973 2.7 L version generated 56 hp per naturally aspirated litre of piston displacement . Toyota 's V engine family were longitudinally mounted V8s used in
IOE engine - Misplaced Pages Continue
3008-644: The Australian Capital Territory , Tasmania and the Northern Territory , it is compulsory to complete a basic rider training course before being issued a Learners Licence, after which they can ride on public roads. In Canada, motorcycle rider training is compulsory in Quebec and Manitoba only, but all provinces and territories have graduated licence programs which place restrictions on new drivers until they have gained experience. Eligibility for
3102-482: The Craig Vetter Fuel Economy Challenge "on real highways – in real conditions". Due to low engine displacements (100–200 cc (6.1–12.2 cu in)), and high power-to-mass ratios, motorcycles offer good fuel economy. Under conditions of fuel scarcity like 1950s Britain and modern developing nations, motorcycles claim large shares of the vehicle market. In the United States,
3196-705: The FIM in the light of the safety concerns. From the 1960s through the 1990s, small two-stroke motorcycles were popular worldwide, partly as a result of East German MZs Walter Kaaden's engine work in the 1950s. In the 21st century, the motorcycle industry is mainly dominated by Indian and Japanese motorcycle companies. In addition to the large capacity motorcycles, there is a large market in smaller capacity (less than 300 cc) motorcycles, mostly concentrated in Asian and African countries and produced in China and India. A Japanese example
3290-478: The Fatality Analysis Reporting System show that for passenger cars, 18.62 fatal crashes occur per 100,000 registered vehicles. For motorcycles this figure is higher at 75.19 per 100,000 registered vehicles – four times higher than for cars. The same data shows that 1.56 fatalities occur per 100 million vehicle miles travelled for passenger cars, whereas for motorcycles the figure
3384-612: The Lotus-Ford Twin Cam . Hemispherical chambers were a feature of the M102 engine introduced in 1980, which together with the crossflow head design promoted greater efficiency over the M115 engine it replaced. The MGA Twin-Cam was a variant of the pushrod MGA 1600 MkI MG MGA line from 1958 to 1960. The original pushrod 1588 cc cast iron block was fitted with a cast aluminum twin-cam two-valve cylinder head. Early versions proved fragile on
3478-500: The US Department of Transportation , the number of fatalities per vehicle mile traveled was 37 times higher for motorcycles than for cars. The term motorcycle has different legal definitions depending on jurisdiction (see § Legal definitions and restrictions ). There are three major types of motorcycle: street, off-road, and dual purpose. Within these types, there are many sub-types of motorcycles for different purposes. There
3572-496: The 1920s stood out. Initially, using converted a Woodmann-designed OHV Blackburne engine it became the first 350 cc to exceed 100 mph (160 km/h), recording 100.81 mph (162.24 km/h) over the flying kilometre during April 1924.[7] Later, Chater-Lea set a world record for the flying kilometre for 350 cc and 500 cc motorcycles at 102.9 mph (165.6 km/h) for the firm. Chater-Lea produced variants of these world-beating sports models and became popular among racers at
3666-866: The 1930 Van Ranst -designed Packard V12 engine, although in this case the valves were both in the block as side valves and the spark plug was poorly placed at the extremity of the combustion chamber. The IOE valvetrain layout was used extensively in early American motorcycles, mainly based on a French design by De Dion-Bouton . Harley-Davidson used IOE engines with atmospheric inlet valves until 1912, and with mechanically driven inlet valves from 1911 to 1929. Indian used IOE valvetrains on all of their four-cylinder bikes except those built in 1936 and 1937. Other American motorcycle manufacturers that used IOE engines included Excelsior , Henderson , and Ace . Hudson used an IOE inline-four engine in its Essex line of cars from 1919 to 1923 and an IOE straight-six engine in its Hudson line of cars from 1927 to 1929. In Europe in
3760-516: The 1960s. Chrysler has produced three generations of such engines: the Chrysler FirePower engine in the 1950s; the 426 Hemi ), developed for NASCAR in 1964 and produced through the early 1970s; and the "new HEMI" from 2003 to 2024. The most recent rendition of the Chrysler "Hemi" engine uses part of an oblate spheroid (flattened sphere) for its head shape to improve combustion efficiency over
3854-561: The B series engines for British Army combat vehicles which were produced in four, six and eight cylinder versions(the B40, B60 and B80) by Rolls-Royce (and in the case of the B40 used in the Austin Champ by Morris Motors)for military vehicles, fire appliances and even buses. A more advanced shorter stroke passenger car development the FB60 engine, a straight-six IOE engine displacing 3909cc and producing
IOE engine - Misplaced Pages Continue
3948-466: The First World War, motorbike production was greatly ramped up for the war effort to supply effective communications with front line troops. Messengers on horses were replaced with despatch riders on motorcycles carrying messages, performing reconnaissance and acting as a military police. American company Harley-Davidson was devoting over 50% of its factory output toward military contract by the end of
4042-525: The Indian Four had the valve positions reversed, with the exhaust valve in the head and the inlet valve in the block. In theory, this would improve fuel vaporization, and the engine was actually more powerful. However, the new system made the cylinder head very hot. The exhaust valve linkage required frequent adjustment. The design returned to the original IOE configuration in 1938. Motorcycle A motorcycle ( motorbike , bike , or, if three-wheeled,
4136-521: The Isle of Man TT. Today, the firm is probably best remembered for its long-term contract to manufacture and supply AA Patrol motorcycles and sidecars. By the late 1920s or early 1930s, DKW in Germany took over as the largest manufacturer. In the 1950s, streamlining began to play an increasing part in the development of racing motorcycles and the "dustbin fairing" held out the possibility of radical changes to motorcycle design. NSU and Moto Guzzi were in
4230-581: The United States by organisations ranging from state agencies to non-profit organisations to corporations. Most states use the courses designed by the Motorcycle Safety Foundation (MSF), while Oregon and Idaho developed their own. All of the training programs include a Basic Rider Course, an Intermediate Rider Course and an Advanced Rider Course. In Ireland , since 2010, in the UK and some Australian jurisdictions, such as Victoria , New South Wales ,
4324-531: The actual enclosed space is generally less than half. Hemispherical cylinder heads have been used since at least 1901; they were used by the Belgian car maker Pipe in 1905 and by the 1907 Fiat 130 HP Grand Prix racer. The Peugeot Grand Prix car of 1912 and the Alfa Romeo Grand Prix car of 1914 were both four-valve engines, and Daimler and Riley were also using hemispherical combustion chambers at
4418-417: The art at the time. Starting was by compressed air. The engine was liquid-cooled, with a radiator over the rear driving wheel. Speed was controlled by means of a throttle valve lever. No braking system was fitted; the vehicle was stopped by raising and lowering the rear driving wheel using a foot-operated lever; the weight of the machine was then borne by two small castor wheels. The driver was seated between
4512-463: The atmospheric pressure of 15 PSI limits the total force available from creating a pressure differential, meaning that a 15 pounds (6.8 kg) spring is theoretical limit while for practical purposes, lighter springs were typically used. When the limits of this system were reached, the design was improved without substantial changes to the head casting by adding a mechanical system to open the inlet valves and stronger springs to close them. In both cases,
4606-403: The average motorcycle fuel economy is 44 miles per US gallon (19 km per liter). Very high fuel economy equivalents are often derived by electric motorcycles. Electric motorcycles are nearly silent, zero-emission electric motor-driven vehicles. Operating range and top speed are limited by battery technology. Fuel cells and petroleum-electric hybrids are also under development to extend
4700-560: The awareness of motorcycles on the country's roads. The campaign, while strongest in the Gauteng province, has representation in Western Cape, KwaZulu Natal and the Free State. It has dozens of trained marshals available for various events such as cycle races and is deeply involved in numerous other projects such as the annual Motorcycle Toy Run. Motorcycle safety education is offered throughout
4794-412: The block was machined at an angle, with the piston crowns angled in a "pitched roof" to match. At TDC, the piston almost touched the angled inlet valve and provided good ' squish ' to the combustion chamber itself, offset to the side by half a cylinder diameter. The resultant combustion chamber shape was a near-ideal hemisphere, although inverted and tilted from the usual " hemi-head " design. The spark plug
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#17328686979124888-453: The chamber and necessitate a " cross-flow " head design. Since the combustion chamber is virtually a hemisphere, a flat-topped piston yields a lower compression ratio unless a smaller chamber is utilized. Significant challenges in the commercialization of engines utilizing hemispherical chambers revolved around the design of the valve actuation, and how to make it effective, efficient, and reliable at an acceptable cost, which normally requires
4982-439: The combustion chamber. The exhaust manifold and its valves are located beside or as part of the cylinders, in the block. The exhaust valves are either roughly or exactly parallel with the pistons; their faces point upwards and they are not operated by separate pushrods, but by contact with a camshaft through the tappet or valve lifter and an integrated valve stem/pushrod. The valves were offset to one side, forming what seemed to be
5076-489: The completely new 385-series engine family, which used a modified Semi-Hemi form of the hemispherical chamber. In the 1970s, Ford designed and produced a small-block "Windsor" engine with hemispherical heads to address the growing concerns about fuel economy. Unfortunately, even with an ahead-of-its-time direct fuel injection system feeding a stratified charge chamber, the hemi's emissions could not be made clean enough for compliance with regulations. This plus
5170-470: The cost of the valve actuation systems, along with the cost of the high pressure pump needed to deliver fuel directly into the chamber, as well as the gilmer belt drive system needed to drive the pump, made further development pointless at the time. Most 1980s 4-cylinder Fords used the Ford CVH engine , "CVH" meaning Compound Valve, Hemispherical (combustion chamber). Post 1986 the cylinder head of this engine
5264-469: The cylinder head, and it requires an inlet valve and ports in the cylinder head, while the cylinder of a sidevalve engine is simply a closed-end cylinder. Rover used a more advanced form of IOE engine. It was designed by Jack Swaine in the mid-late 1940s and was in production from 1948 to the early 1990s. Unlike the conventional F-head IOE, this had an efficient combustion chamber designed for good combustion, rather than simple manufacture. The top surface of
5358-407: The diameters of valve heads to total no more than the bore of the cylinder in a two valve per cylinder arrangement. With a hemispherical chamber with splayed valve stem angle, this limitation is increased by the angle, making the total valve diameter size possible to exceed the bore size within an overhead valve configuration. See IOE engine for another method. Also, the splayed valve angle causes
5452-514: The direction opposite of the desired turn. This practice is counterintuitive and therefore often confusing to novices – and even many experienced motorcyclists. With such short wheelbase , motorcycles can generate enough torque at the rear wheel, and enough stopping force at the front wheel, to lift the opposite wheel off the road. These actions, if performed on purpose, are known as wheelies and stoppies (or endos) respectively. Various features and accessories may be attached to
5546-460: The exhaust valves were in the block and were opened by contact with a camshaft through a tappet or valve lifter and closed by springs. The IOE design allows the use of larger valves than a sidevalve (or L-head) or overhead valve engine. Its advantages over the sidevalve/flathead also include a compact combustion chamber, a well-located spark plug, and a cooling effect from the mixture swirl, along with better intake mixture flow. Disadvantages include
5640-474: The first "modern motorcycle". Introduced in 1915 it had a 550 cc side-valve four-stroke engine with a three-speed gearbox and belt transmission. It was so popular with its users that it was nicknamed the "Trusty Triumph". By 1920, Harley-Davidson was the largest manufacturer, with their motorcycles being sold by dealers in 67 countries. Amongst many British motorcycle manufacturers, Chater-Lea with its twin-cylinder models followed by its large singles in
5734-429: The five brands with enough data to draw conclusions, Honda, Kawasaki and Yamaha were statistically tied, with 11 to 14% of those bikes in the survey experiencing major repairs. Harley-Davidsons had a rate of 24%, while BMWs did worse, with 30% of those needing major repairs. There were not enough Triumph and Suzuki motorcycles surveyed for a statistically sound conclusion, though it appeared Suzukis were as reliable as
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#17328686979125828-515: The front wheels. It was not, however, a success, as Butler failed to find sufficient financial backing. Many authorities have excluded steam powered , electric motorcycles or diesel-powered two-wheelers from the definition of a 'motorcycle', and credit the Daimler Reitwagen as the world's first motorcycle. Given the rapid rise in use of electric motorcycles worldwide, defining only internal-combustion powered two-wheelers as 'motorcycles'
5922-447: The geometry of the motorcycle itself. These factors create a set of three basic postures. Factors of a motorcycle's ergonomic geometry that determine the seating posture include the height, angle and location of footpegs, seat and handlebars. Factors in a rider's physical geometry that contribute to seating posture include torso, arm, thigh and leg length, and overall rider height. Hemi-head A hemispherical combustion chamber
6016-414: The head, and allows for two large valves . However, a hemi-head usually allows no more than two valves per cylinder due to the difficulty in arranging the valve gear for four valves at diverging angles, and these large valves are necessarily heavier than those in a multi-valve engine of similar valve area, as well as generally requiring more valve lift. The intake and exhaust valves lie on opposite sides of
6110-403: The more usual side- or overhead valve designs. The unusual combustion chamber arrangement with its angled valves also led to an unusual valve train. The block-mounted camshaft operates small wedge shaped rockers, one for each valve. In early models the camshaft acts on a simple pad on the rocker, but for later models this pad was replaced by a roller follower. The exhaust rockers act directly on
6204-555: The new internal combustion engine. As the engines became more powerful and designs outgrew the bicycle origins, the number of motorcycle producers increased. Many of the nineteenth-century inventors who worked on early motorcycles often moved on to other inventions. Daimler and Roper, for example, both went on to develop automobiles. At the end of the 19th century the first major mass-production firms were set up. In 1898, Triumph Motorcycles in England began producing motorbikes, and by 1903 it
6298-408: The other three Japanese brands while Triumphs were comparable to Harley-Davidson and BMW. Three-fourths of the repairs in the survey cost less than US$ 200 and two-thirds of the motorcycles were repaired in less than two days. In spite of their relatively worse reliability in this survey, Harley-Davidson and BMW owners showed the greatest owner satisfaction, and three-fourths of them said they would buy
6392-477: The prestigious Toyota Century from the 1960s through the 1990s. Toyota had worked with Yamaha to produce the first Japanese full aluminum alloy block engine. The V Family is often referred to as the Toyota HEMI as the engine features a similar cylinder head design to those found on the Chrysler's Hemi, even though most of the engine design is completely different. Other Toyota engines (e.g. T , 2M , 4M etc.) at
6486-441: The primary disadvantages are complex valve trains (caused by valves being placed opposite one-another in a head) and expense (of machining the heads and pistons, and additional valve train components). While hemispherical combustion chambers are still found in the 2000s multi-valve arrangements (of four and even five valves per cylinder) and the popularity of overhead cam (including double overhead cam ) arrangements have altered
6580-579: The range and improve performance of the electric drive system. A 2013 survey of 4,424 readers of the US Consumer Reports magazine collected reliability data on 4,680 motorcycles purchased new from 2009 to 2012. The most common problem areas were accessories , brakes , electrical (including starters , charging , ignition ), and fuel systems , and the types of motorcycles with the greatest problems were touring, off-road/dual sport, sport-touring, and cruisers. There were not enough sport bikes in
6674-400: The same bike again, followed by 72% of Honda owners and 60 to 63% of Kawasaki and Yamaha owners. Two-wheeled motorcycles stay upright while rolling due to a physical property known as conservation of angular momentum in the wheels. Angular momentum points along the axle, and it "wants" to stay pointing in that direction. Different types of motorcycles have different dynamics and these play
6768-569: The same period Humber Limited of Coventry, England produced a full range of cars using IOE engines, these were however phased out at the end of the 1920s in favour of models using cheaper L head engines shared with Hillman Post WW2 Willys , and its successor Kaiser-Jeep , used variants of the Willys Hurricane engine from 1950 to 1971. Rolls-Royce used an IOE straight-six engine originally designed immediately prior to WW2 in their post-war Silver Wraith . From this engine Rolls-Royce derived
6862-466: The same time as the American Roper steam velocipede , built by Sylvester H. Roper of Roxbury, Massachusetts , who had been demonstrating his machine at fairs and circuses in the eastern U.S. since 1867. Roper built about 10 steam cars and cycles from the 1860s until his death in 1896. In 1894, Hildebrand & Wolfmüller became the first series production motorcycle, and the first to be called
6956-467: The side oiler engine block modified to replace an in-block cam with an idler shaft driving the distributor and oil pump, and accommodate other overhead camshaft issues. The overhead cams meant that it was not as rpm-limited as the Chrysler Hemis were with their pushrods and heavy and complex valvetrains. Because of its power output, and the fact that Chrysler had showed NASCAR chief Bill France that
7050-530: The street and in competition due to pre-ignition ( detonation ), and oil loss, which led to decreasing the compression ratio from 9.1. to 8.3 with redesigned pistons. It was a successful update but sales dropped off so rapidly the company halted Twin Cam production and used the matching chassis for some MGAs, with pushrod engines, known as the MGA 1600 MkI and MkII DeLuxe models. Mitsubishi produced several hemi engines including
7144-621: The street as well. Each configuration offers either specialised advantage or broad capability, and each design creates a different riding posture. In some countries the use of pillions (rear seats) is restricted. The first internal combustion , petroleum fueled motorcycle was the Daimler Reitwagen . It was designed and built by the German inventors Gottlieb Daimler and Wilhelm Maybach in Bad Cannstatt , Germany, in 1885. This vehicle
7238-471: The survey for a statistically significant conclusion, though the data hinted at reliability as good as cruisers. These results may be partially explained by accessories including such equipment as fairings, luggage, and auxiliary lighting, which are frequently added to touring, adventure touring/dual sport and sport touring bikes. Trouble with fuel systems is often the result of improper winter storage, and brake problems may also be due to poor maintenance. Of
7332-399: The time used a hemispherical combustion chamber. The spark plugs were located at the top of the combustion chamber. In the modern emissions-era, the hemi-chamber has morphed into more sophisticated and complex designs that are able to extract more power with lower emissions from any given combustion event. Many of today's engines use "active combustion chambers" designed to tumble and swirl
7426-633: The time. Beginning in 1912, Stutz used four-valve engines, conceptually anticipating modern car engines. Other examples include the BMW double-pushrod design (adopted by Bristol Cars ), the Peugeot 403 , the Toyota T engine and Toyota V engine (Toyota's first V8 engine), Miller racing engines, and the Jaguar XK engine . A hemispherical head ("hemi-head") gives an efficient combustion chamber with minimal heat loss to
7520-455: The traditional trade-offs in employing "hemi heads". Hemispherical combustion chambers were introduced on some of the earliest automotive engines, shortly after the viability of the internal combustion engine was first demonstrated. Their name reflects the domed recess in a cylinder head and correspondingly shaped top of a piston enclosing a space that approximates a half of a sphere ( hemi- + -sphere + -ical ), although in practice
7614-474: The use of either a dual rocker system, or dual camshafts to operate the inlet and exhaust valves. Complexity was referenced early in Chrysler's development of their 1950s hemi engine: the head was referred to in company advertising as the Double Rocker head. Ford's CVH (Compound Valve Hemispherical) engine of the 1980s solved the problem by way of utilizing a complex geometry of the valve angle combined with
7708-455: The valve seat plane to be tilted, giving a straighter flow path for the intake and exhaust to/from the port exiting the cylinder head. Engineers have learned that while increasing the valve size with straighter port is beneficial for increasing the maximum power at high rpm, it slows the intake flow speed, not providing the best combustion event for emissions, efficiency, or power in the normal rpm range. Domed pistons are commonly used to maintain
7802-512: The valves in a flathead engine. The earliest IOE layouts used atmospheric inlet valves which were held closed with a weak spring and were opened by the pressure differential created when the piston went down on the inlet stroke . This worked well with low-speed early engines and had the benefit of being very simple and cheap, but the weak spring was unable to close the valve fast enough as engine speed increased. This required stronger springs, which in turn required direct mechanical action to open, as
7896-483: The valves, whilst the inlet rockers act on pushrods running up to a second set of longer flat rockers operating the inlet valves. The Rover engine, like many 1940s and earlier British designs, was a small bore, long stroke ( undersquare ) engine to keep the RAC tax horsepower rating as low as possible, thus keeping the road tax as low as possible. The IOE layout enabled Rover to use larger valves than would normally be possible in
7990-462: The vanguard of this development, both producing very radical designs well ahead of their time. NSU produced the most advanced design, but after the deaths of four NSU riders in the 1954–1956 seasons, they abandoned further development and quit Grand Prix motorcycle racing . Moto Guzzi produced competitive race machines, and until the end of 1957 had a succession of victories. The following year, 1958, full enclosure fairings were banned from racing by
8084-449: The war. The British company Triumph Motorcycles sold more than 30,000 of its Triumph Type H model to allied forces during the war. With the rear wheel driven by a belt, the Model H was fitted with a 499 cc (30.5 cu in) air-cooled four-stroke single-cylinder engine. It was also the first Triumph without pedals . The Model H in particular, is regarded by many as having been
8178-404: The years. Arguably one of their most beloved examples is Giuseppe Busso 's original 2.5-liter V6 , which has been cited by some as one of the best and most distinctive sounding production engines (even in its later 24v forms) of all time. Part of this praise is likely because the hemispherical heads on the original 2-valve engine allowed for an almost completely straight exhaust port, resulting in
8272-481: Was a three-wheeled vehicle, with the rear wheel directly driven by a 5 ⁄ 8 hp (0.47 kW), 40 cc (2.4 cu in) displacement, 2 + 1 ⁄ 4 in × 5 in (57 mm × 127 mm) bore × stroke, flat twin four-stroke engine (with magneto ignition replaced by coil and battery) equipped with rotary valves and a float-fed carburettor (five years before Maybach ) and Ackermann steering , all of which were state of
8366-491: Was centrally mounted and this, together with the turbulence generated by the squish, provided a short flame path. The thinness of the gas layer between piston and inlet valve was so confined as to reduce the risk of detonation on poor fuel, one factor that kept it in service with Land Rover for so long. During the late 1940s and early 1950s when the only petrol available was low octane 'pool' petrol it also allowed Rover to run higher compression ratios than many competitors with
8460-803: Was designed as an expedient testbed for their new engine, rather than a true prototype vehicle. The first commercial design for a self-propelled cycle was a three-wheel design called the Butler Petrol Cycle, conceived of Edward Butler in England in 1884. He exhibited his plans for the vehicle at the Stanley Cycle Show in London in 1884. The vehicle was built by the Merryweather Fire Engine company in Greenwich , in 1888. The Butler Petrol Cycle
8554-447: Was producing over 500 bikes. Other British firms were Royal Enfield , Norton , Douglas Motorcycles and Birmingham Small Arms Company who began motorbike production in 1899, 1902, 1907 and 1910, respectively. Indian began production in 1901 and Harley-Davidson was established two years later. By the outbreak of World War I, the largest motorcycle manufacturer in the world was Indian, producing over 20,000 bikes per year. During
8648-779: Was reworked to heart-shaped lean-burn combustion chambers, and used in low-performance models not benefiting from multipoint fuel injection - 1.4, 1.6, 1.8 in Europe, though was still referred to colloquially as the CVH. The hemi-head Jaguar XK engine , introduced in 1949, powered cars ranging from the Le Mans winning D-Type to the XJ6 . The Lamborghini V12 , designed in 1963 and produced for more than 50 years, used hemispherical chambers. The Lancia V4 and Lancia V6 engines both used hemispherical combustion chambers. Lotus has used hemispherical chambers, as in
8742-506: Was the first internal combustion, petroleum -fueled motorcycle. In 1894, Hildebrand & Wolfmüller became the first series production motorcycle. Globally, motorcycles are comparable numerically to cars as a method of transport: in 2021, approximately 58.6 million new motorcycles were sold around the world, while 66.7 million cars were sold over the same period. In 2022, the top four motorcycle producers by volume and type were Honda , Yamaha , Kawasaki , and Suzuki . According to
8836-464: Was unlike either the safety bicycles or the boneshaker bicycles of the era in that it had zero degrees of steering axis angle and no fork offset , and thus did not use the principles of bicycle and motorcycle dynamics developed nearly 70 years earlier. Instead, it relied on two outrigger wheels to remain upright while turning. The inventors called their invention the Reitwagen ("riding car"). It
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