Motorcycle engine
A motorcycle engine is an engine that powers a
Although some mopeds, such as the VéloSoleX, had friction drive to the front tire, a motorcycle engine normally drives the rear wheel, power being sent to the driven wheel by belt, chain or shaft. Historically, some 2,000 units of the Megola were produced between 1921 and 1925 with front wheel drive,[1] and the modern Rokon, an all terrain motorcycle with both wheels driven, has been produced since 1960.[2]
Most engines have a gearbox with up to six or even 7 ratios. Reverse gear is occasionally found on heavy tourers, for example the Honda GL1600, and sidecar motorcycles, such as the Ural. The rider changes gears on most motorcycles using a foot-pedal and manual clutch, but early models had hand-levers. More recently, some have automatic or semi-automatic gearboxes, and some using CVT transmission.
Outside the United States, engine capacities typically ranged from about 50 cc to 650 cc; but in Europe since 1968 motorcycles with larger capacities have become common, ranging as high as the Triumph Rocket 3's 2,300 cubic centimetres (140 cu in) engine. In the United States, V-twin engined motorcycles with capacities of 850 cc or more have been the norm since the 1920s.
History
The first motorcycles were powered by steam engines. The earliest example is the French Michaux-Perreaux steam velocipede of 1868. This was followed by the American Roper steam velocipede of 1869, and a number of other steam powered two and three wheelers, manufactured and sold to the public on through the early 20th century.[3]
Using
The Otto cycle gasoline internal combustion engine was first used on an experimental two-wheeler created by Gottlieb Daimler to test the practicality of such an engine in a vehicle. This motorcycle, the Daimler Reitwagen, is credited as the world's first motorcycle by many authorities, partially on the assumption that a motorcycle is defined not as any two-wheel motor vehicle, but a two-wheel internal combustion engine motor vehicle.[3] The Oxford English Dictionary, for example, defines the word motorcycle this way.[4][5] The steam cycles were also simply neglected and forgotten by many historians, even as the Michaux-Perreaux waited forty years[verification needed] on display in the National Motor Museum, Beaulieu.[verification needed][6]
In recent years, a surge in interest in clean energy has put many new electric powered two wheelers on the market, and they are registered as motorcycles or scooters, without the type of powerplant being an issue. Diesel motorcycles were also experimented with briefly in the 20th century, and are again the subject of interest due to fuel economy and the needs of military logistics. The USMC has ordered a new diesel motorcycle, the M1030 M1, that can use the same fuel, JP-8, as the rest of their armored vehicles, aircraft, cars and trucks.[7]
The overwhelming majority of the motorcycles produced and used in the world today have small displacement air-cooled single-cylinder engines, both two- and four-strokes.[citation needed] In the wealthier parts of the world, Europe and Japan, larger displacements and multiple cylinders are common alongside small-displacement bikes required by various licensing and rider experience requirements, and so a very diverse range of sizes, cylinder numbers, configurations, and cooling systems are seen on the road. Many developed countries have graduated licensing, where a rider is licensed for a period of time to ride only smaller-displacement motorcycles before being allowed to ride larger ones. In the United States, there are no such mandates, and so the mix is skewed even further to the largest displacements, consumer demand drives manufacturers to offer their largest motorcycles to that country, and to export far fewer sub-600 cc (37 cu in) models to the American market.[citation needed]
Types
Almost all production motorcycles have gasoline
Motorcycle engines can be mounted transversely; with the crankshaft aligned perpendicular to the frame or longitudinally, with the crankshaft parallel to the frame. Motorcycles with transversely mounted engines are more suited to have chain or belt final-drive. Motorcycles with longitudinally mounted engines are more suited for shaft final-drive.
Two-stroke and four-stroke
Two-stroke engines have fewer moving parts than four-stroke engines, and produce twice the number of power strokes per revolution.
Fuel economy is better in four-strokes due to more complete combustion of the intake charge in four-stroke engines.[citation needed]
Nevertheless, two-strokes have been largely replaced on motorcycles in developed nations due to their environmental disadvantages. Cylinder lubrication is necessarily total-loss and this inevitably leads to a smokey exhaust, particularly on wide throttle openings. Two-stroke-engined motorcycles continue to be made in large numbers, but mostly off-road
Cylinder heads (four-stroke)
Cylinder head design has a significant effect on the efficiency of combustion, and hence the power output of the engine. The head may be
Some motorcycles such as Harley-Davidsons, Moto Guzzis and BMWs become identifiable by their cylinder-head types, namely
Valve control in four-strokes
In a
The earliest motorcycle engines had exhaust valves operated in the same way as a side-valve engine, but they had overhead intake valves held closed by a weak spring. The intake valve was opened by the suction caused by the intake stroke. As the need for mechanical control of the intake valve arose, the design was modified by adding another cam to the camshaft and using a pushrod and rocker arm to operate the intake valve.[9]
Honda equipped the CBR400F with REV, described as "revolution responding type valve pausing mechanism", in 1983.
Unit construction
Engines and gearboxes were originally separate items, the gearbox being driven by a "primary chain". Later designs combined the two elements into a single "unit construction". Some manufacturers, such as Norton and Enfield continued with "pre-unit" construction until recently, and Harley-Davidson still makes pre-unit engines today.
In the early 1960s, BSA introduced new short-stroke unit construction 500 and 650 cc parallel twins to replace their existing pre-unit long-stroke engines. Triumph modified their large pre-unit 500 and 650 cc parallel twins into unit-construction engines. The smaller Triumph 350 and 500 cc twins had been unit construction from their introduction in 1957. The decision by Lucas to discontinue making dynamos and magnetos, and to produce only alternators and coil ignition systems, was a significant factor in forcing the redesign.[citation needed]
Traditionally, engines and gearboxes had separate lubrication systems with different grades of oil; but modern practice is to use the same oil for both.[citation needed]
Cylinders and configuration
Generally, motorcycle engines have between one and six cylinders.[12] The majority of motorcycle engines are configured as singles, parallel twins, triples, fours and sixes; and all these may be inline or transverse. Vee engines include V-twins and V-fours, and horizontally opposed engines include flat-twins, flat-fours and flat-sixes. Wankel engines are either single-rotor or twin-rotor. Bigger bikes tend to have more cylinders for smoothness and increased power. Modern singles range in capacity from 50 cc to 660 cc, twins from 175 cc to 1,800 cc, triples from 380 cc to 2,300 cc, and so on.
Single
Single-cylinder engines (a.k.a. "singles" or "thumpers") have the cylinder vertical, inclined or horizontal, the last type most common in step-through motorcycles. Single-cylinder engines require both a larger flywheel and a heavier-duty gearbox than multicylinder engines. Small singles are cheap to build and maintain and are suitable as cheap utility motorcycles.
Until the mid-1960s, road-racing machines, like the UK's Matchless, AJS and Norton, tended to be large singles, but since then multicylinder racers have become the norm. Off-road and smaller dual-sport bikes tend to use single-cylinder engines. The simplicity of these engines, often relying on a single carburetor, make them relatively easy to maintain and repair in remote locations with few tools.
Compared to lightweight off-road singles, the modern category of heavier off-road adventure bikes tend to forgo such simplicity, and instead have larger and more powerful parallel-twin, flat-twin, or V-twin engines.
Twin
- Straight-twin
Starting with Edward Turner's 1937 Triumph Speed Twin design, and until the mid-1970s, the parallel-twin was the most common British motorcycle type. Parallel-twins are usually mounted transversely, with the cylinders side by side above the crankshaft, and with exhaust pipes at the front, in the cool airstream. Longitudinal, or inline, twins include the 500 cc Sunbeam S7 and S8. There are three crankshaft configurations for this engine: 360°, 180°, and the newer 270°. Parallel twins usually have only two main bearings.
- V-twin
In a V-twin engine the cylinders form a "V" around the crankshaft. A Vee-angle of 90°, as used by Ducati and Moto Guzzi, can give perfect primary and secondary balance, with a pleasingly irregular firing order. A lesser angle gives a more compact motor, but one which is prone to vibration, such as 42° (Indian), 45° (Harley-Davidson), 52° Honda, and 60° (Aprilia). Most V-twins have a single crankpin shared by side-by-side connecting rods so that the cylinders are slightly offset, but a variation is to have a single crankpin with "fork & blade" con-rods, to keep the cylinders in line. Non-90° V-twins may have offset crankpins to try to reduce vibration.
V-twins may be mounted either longitudinally with the cylinders protruding either side, like the
- Flat-twin
In a flat-twin, or boxer, engine the cylinders are horizontally opposed. The boxer has perfect primary balance, and only a small rocking couple, and unlike a V-twin, regular firing intervals, producing very low vibration levels, without the use of counterbalance shafts. They are usually mounted with a longitudinal crankshaft, with the cylinders protruding into the airstream, so that a flat-twin can satisfactorily be air-cooled. Flat-twins are made by BMW and Ural and historically by Douglas, Marusho, and Hoffmann, among others. The longitudinal mounting makes the flat twin highly suitable for shaft final drive.
Some early motorcycles used transverse-crank flat twin engines, especially Douglas motorcycles before World War II.
- Tandem twin
The Tandem Twin where the cylinders are longitudinal, and have two cranks geared together such as
Triple
- Inline triple
Three-cylinder engines, a.k.a.
Some triples were two-strokes. The Kawasaki triples were produced with capacities of 250, 350, 400, 500, and 750 cc in the 1970s, while Suzuki produced 380, 550, and 750 triples, the last being water-cooled. Motobecane made 350 cc and fuel-injected 500 cc triples with 3 into 4 pipes in the early seventies. Honda produced the water-cooled V-3 two-strokes MVX250 and NS400. There have been various race bike triples such as Kawasaki KR750, Suzuki TR750 transverse 3s, and Proton/Modenas KR3, Honda NS500 V-3s.
Four
Four-cylinder engines are most commonly found in a transverse-mounted
- Inline four
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Production of four cylinder motorcycles began with the
The first across-the-frame 4-cylinder motorcycle was the racer 1939
- Flat four
This section needs expansion. You can help by adding to it. (December 2009) |
A flat-4 or horizontally opposed-4 is a flat engine with four cylinders arranged horizontally in two banks of two cylinders on each side of a central crankcase. The pistons are usually mounted on the crankshaft such that opposing pistons move back and forth in opposite directions at the same time, somewhat like a boxing competitor punching their gloves together before a fight, which has led to it being referred to as a boxer engine. The configuration results in inherently good balance of the reciprocating parts, a low centre of gravity, and a very short engine length.
- V4
Honda uses V4 engines in the ST series and VFR series. As for two-stroke engines, there were four cylinders in the smaller classes such as Kawasaki's 125 cc KR3 square 4 and Yamaha's 250 cc RD500 V4 (RZ 500 in the US). Yamaha later raced transverse four TZ500/700/750's and virtually all the bikes in the last decade of the two-stroke GP500 era were fours, first squares then Vs, by Honda, Kawasaki, Cagiva, Suzuki, Yamaha. Kawasaki also experimented with a trapezoidal four the 602S. Yamaha made the V4 RD500LC, and Suzuki the RG400 and RG500 square four road bikes.
- Square four
A square four is a U engine with two cylinders on each side. This configuration was used on the Ariel Square Four motorcycle from 1931 to 1959. This design was revived as a two-stroke version on some racing Suzuki models, and their subsequent road-going version the RG500. Although some racing success was achieved, the road bikes didn't sell in great numbers, and the design was phased out in favor of in-line, four-stroke designs, as at the time two-stroke engines were quickly being superseded by more economical, reliable, and emissions-friendly four-strokes.
Five
- V5
Honda has produced five-cylinder engines for racing, the RC211V 990 cc V5. No V5 engines are currently available in commercial production motorcycles.
Just prior to their collapse,
Six
- Inline six
The 1,047 cc
- Flat 6
The six-cylinder engine is currently used by Honda in the Gold Wing, and had previously been used in the Valkyrie and the Rune, both of which were cruiser developments of the Gold Wing.
V8
Other types
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- Wankel rotary
Wankel engines produce high power outputs for their size and weight, and several attempts were made to produce Wankel powered motorcycles in the 1970s. Yamaha and Kawasaki exhibited Wankel-powered motorcycles in 1972, but neither company manufactured one. German manufacturer Hercules, a member of the Sachs-controlled Zweirad Union, produced their single-rotor W2000 from 1974 to 1977. Suzuki produced their single-rotor RE5 from 1975 to 1976. Van Veen built 38 OCR1000 motorcycles with twin-rotor Comotor engines between 1978 and 1981.
BSA experimented with Wankel engines before they ended production in the 1970s. These experiments later led to Wankel-engined Norton motorcycles in the 1980s and 1990s, including the Classic, the Commander, the fleet-only Interpol 2, and the F1. Steve Hislop won the 1992 Senior TT on a Wankel-powered Norton.
- Oval pistons
- Rotary engines
Megola, Killinger and Freund Motorcycle
- Turbine engines
- MTT Turbine Superbike (turboshaft)
- Jet Reactionafterburning turbojet
Other jet engine motorcycle prototypes exist,[20] but never have been commercialized.
- Rocket
Several rocket-powered motorcycles have been built,[21] including:
- Fritz von Opel's 1928 "Monster" rocket bike
- Skycycle X-2 rocket developed for Evel Knievel's Snake River Canyon jump attempt
- Eric Teboul's rocket-powered dragbike that set the world record at Santa Pod Raceway in 2009[21]
Electric
This section needs expansion. You can help by adding to it. (December 2009) |
Diesel
Only very small numbers of
Several armies are moving to an all-diesel engine fleet to reduce the fire risks of gasoline and the need to provide two different fuels. This includes their dispatch riders as well, encouraging the market for diesel motorcycles. Interest in biofuels is also likely to encourage future developments for small Diesels.
Diesels are also available in both two- and four-stroke versions.
Engine cooling
Liquid
Liquid-cooled motorcycles have a radiator, similar to the radiator on a car, which is the primary way their heat is dispersed. Coolant is constantly circulated between this radiator and the cylinders when the engine is running. While most off-road motorcycles have no radiator fan and rely on air flowing over the radiators from the forward motion of the motorcycle, many road motorcycles have a small fan attached to the radiator which is controlled by a thermostat. Some off-road motorcycles are liquid-cooled, and anti-dirt protection is attached to the radiator. The cooling effect of this fan is enough to prevent the engine overheating in most conditions, so liquid-cooled bikes are safe to use in a city, where traffic may frequently be at a standstill.
Emissions regulations and the market demand for maximum power are driving the motorcycle industry to liquid-cooling for most motorcycles. Even Harley-Davidson, a strong advocate of air-cooled motors, has recently added water cooling to the heads of their V-twin motors in their large touring models, with the radiators being hidden in the lower leg fairings. The Harley-Davidson Street 500, Street 750, and two V-Rod models have 60° V-twins that are fully water cooled, as opposed to the traditional air-cooled 45° V-twins.
Air
Most air-cooled motorcycles take advantage of air blowing past the cylinder and cylinder head while in motion to disperse heat. Frequent, sustained stationary periods may cause overheating. Some models, mostly scooters, are equipped with fans that force the air to go past the cylinder block, which solves the problem of city driving. The cylinders on air-cooled bikes are designed with fin heat sinks to aid in this process. Air-cooled bikes are cheaper, simpler and lighter than their water-cooled counterparts.
Oil
Some manufacturers use a hybrid cooling method where engine oil is circulated between the engine case and a small radiator. Here the oil doubles as cooling liquid, prompting the name "oil-cooling." Suzuki has produced many oil-cooled motorcycles. Modern BMW R-series flat-twin motorcycles, such as the R1150GS, use air and oil cooling. Polaris's Victory motorcycles use oil/air cooling exclusively.
Other components
Fuel Injection
Fuel injection and computer engine management systems are now normal on middle range and larger motorcycles and are increasingly being incorporated onto the smaller machines, partly driven by better emission control and lower maintenance but mostly by manufacturing cost considerations.
Ignition
Ignition systems moved from magneto in the 1950s to battery-coil-contact breaker points, and these were increasingly superseded by Capacitor Discharge Ignition (CDI) from the 1980s. Small, single-cylinder motorcycles abandoned the flywheel magneto system with contact breakers to similar flywheel driven solid-state systems at about the same time.
Turbo and Superchargers
Superchargers, or blowers, were common in the GPs, until they were banned. The first supercharger on a production motorcycle was the 2015 Kawasaki Ninja H2 and H2R.[24] The big four made a turbocharged bike, and Honda made two, mainly as an exercise in technical expertise and later discontinued them for more conventional methods. Bolt-on superchargers are available for street bikes and are essential for performance applications such as drag bikes and land speed record streamliners. Most sports bikes now use a ram-air induction system where as road speed increases, more air is forced through ducts in the fairing to pressurize the airbox. The first on a production motorcycle was the 1990 Kawasaki Ninja ZX-11.[25] Not to be confused with the original Ram-Air system where an air scoop/cowl was fitted to the top of the cylinder heads of Suzuki two-stroke engines to aid cooling.
See also
- List of motorcycles by type of engine
- Motorcycle motor powered car
- List of motorized trikes
- Aircraft engine
References
- ^ Revoluntionary eccentricities: A survey of the rotary engine over the years. Motorcycle Sport, April 1983, pp.166-171, p.188 Accessed February 2019
- ^ About Rokon rokon.com Retrieved February 2019
- ^ ISBN 9780851122007
- ^ |"motorcycle, n.", Oxford English Dictionary Online, Oxford University Press, March 2009,
1. A two-wheeled motor-driven road vehicle, resembling a bicycle but powered by an internal-combustion engine; (now) spec. one with an engine capacity, top speed, or weight greater than that of a moped.
- ISSN 1059-1028
- ^ ISBN 0-89207-207-5
- ISSN 0362-4331
- ^ Mayersohn, Norman (December 3, 2006), "HANDLEBARS; Ducati's GT Brings Back A Saucy Spirit of the '70s", The New York Times,
But 'desmo' has become a code word among enthusiasts, in much the same way that Hemi has become a rallying cry for performance-minded Dodge owners, and Ducati is smart not to abandon the mystique that has grown around it.
- ISBN 0-7513-0043-8.
IOE Inlet over exhaust. Valve layout in which the inlet valve is placed directly over the exhaust valve. Common on early engines, a development of atmospheric valve engines.
- ^ "Honda Worldwide | Technology Close-up". World.honda.com. Archived from the original on 2011-06-04. Retrieved 2010-12-04.
- ^ "2008 Kawasaki Concours 14: MD First Ride (Part 2)". Retrieved 2011-06-30.
- ^ admin, knowledgebook (2022-12-09). "How A Motorcycle Works? Explained Simply - Knowledgebook". Knowledgebook. Retrieved 2022-12-14.
- ^ [1] V-twin Design Engineering (Retrieved 26 November 2006)
- ISSN 0011-4286. Retrieved 2013-09-21.
- LCCN 2005922934. Retrieved 2014-02-03.
Beloved by police departments across the nation, and by connoisseurs in general, the expensive Henderson fours didn't sell in sufficient numbers to remain in production once the Great Depression began in late 1929.
- ISSN 0277-9358. Retrieved 2014-02-03.
In its initial demonstration before police officials, the machine managed a 98-mph pass, plenty of top-end performance to humble the cars and trucks of moonshine runners.
- ISSN 0277-9358. Retrieved 2014-02-03.
- ^ Hamish, Cooper (January–February 2018). "Radical Rondine: 1939 Gilera 500 Rondine". Motorcycle Classics. Retrieved April 13, 2018.
- ^ "Bike" magazine February? 1973
- ^ Vin Marshall (March 12, 2010), Build Your Own Turbojet? Some People Do, Popular Science, retrieved 2012-05-30
- ^ a b The History Of The Rocket-Powered Motorcycle, Jalopnik, May 24, 2010, retrieved 2012-05-30
- ^ "Diesel motorbikes". Journey to Forever. Retrieved 2007-06-28.
- ^ "The first commercially-available diesel motorcycle". Gizmag. November 20, 2006. Retrieved 2007-06-28.
- ^ Kunitsugu, Kent (September 30, 2014). "Kawasaki officially debuts 2015 Ninja H2R". Sport Rider. Retrieved February 14, 2016.
- ^ "Ram Air: Test". Sport Rider. October 1999. Retrieved February 14, 2016.