Single-cylinder engine

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DKW RT 250 (1952-1953) motorcycle engine 2007-05-20 3 DKW RT 250 in Mendig (kl).JPG
DKW RT 250 (1952–1953) motorcycle engine

A single-cylinder engine, sometimes called a thumper, is a piston engine with one cylinder. This engine is often used for motorcycles, motor scooters, go-karts, all-terrain vehicles, radio-controlled vehicles, power tools and garden machinery (such as chainsaws, lawn mowers, cultivators, and string trimmers). Single-cylinder engines are made both as 4-strokes and 2-strokes.

Contents

Characteristics

Villiers engine in a 1959 Bond Minicar Bond minicar engine bay 1959.jpg
Villiers engine in a 1959 Bond Minicar

Compared with multi-cylinder engines, single-cylinder engines are usually simpler and compact. [1] Due to the greater potential for airflow around all sides of the cylinder, air cooling is often more effective for single cylinder engines than multi-cylinder engines. This reduces the weight and complexity of air-cooled single-cylinder engines, compared with liquid-cooled engines.

Drawbacks of single-cylinder engines include a more pulsating power delivery through each cycle and higher levels of vibration. [2] The uneven power delivery means that often a single-cylinder engine requires a heavier flywheel than a comparable multi-cylinder engine, resulting in relatively slower changes in engine speed. To reduce the vibration level, they often make greater use of balance shafts than multi-cylinder engines, [3] as well as more extreme methods such as a dummy connecting rod (for example the Ducati Supermono). [4] [5] These balancing devices can reduce the benefits of single-cylinder engines regarding lower weight and complexity.

Most single-cylinder engines used in motor vehicles are fueled by petrol (and use a four-stroke cycle), [6] [7] [8] however diesel single-cylinder engines are also used in stationary applications (such as the Lombardini 3LD and 15LD).

A variation known as the split-single makes use of two pistons which share a single combustion chamber.

Uses

Yamaha SRX600 (1985-1997) motorcycle engine Detail view of a large single-cylinder air-cooled motorcycle engine.jpg
Yamaha SRX600 (1985–1997) motorcycle engine

Early motorcycles, automobiles and other applications such as marine engines all tended to be single-cylinder. The configuration is almost exclusively used in portable tools, along with garden machinery such as lawn mowers. [9] Single cylinder engines also remain in widespread use in motorcycles, motor scooters, go-karts, auto rickshaws, and radio-controlled models. From 1921 to 1960, the Lanz Bulldog tractor used a large horizontally-mounted single cylinder two-stroke engine. [10] However they are rarely used in modern automobiles and tractors, due to developments in engine technology.

Single cylinder engines remain the most common engine layout in motor scooters and low-powered motorcycles. The Honda Super Cub (the motor vehicle with the highest overall sales since its introduction in 1958) uses a 49 cc (3.0 cu in) four-stroke single-cylinder engine. There are also several single-cylinder sportbikes (such as the KTM 690 Duke R), dual-sport motorcycles (such as the BMW G650GS) and the classic-styled Royal Enfield 500 Bullet. [11] [12]

The Moto3 class in the MotoGP World Championship have used four-stroke 250 cc (15.3 cu in) single cylinder engines since the class replaced 125 cc (7.6 cu in) two-strokes in 2012.

Other single-cylinder engines

Engines of other sorts, like the beam engine and certain types of Stirling engine, operate using one cylinder and thus can also be considered single-cylinder engines.

Related Research Articles

<span class="mw-page-title-main">Reciprocating engine</span> Engine utilising one or more reciprocating pistons

A reciprocating engine, also often known as a piston engine, is typically a heat engine that uses one or more reciprocating pistons to convert high temperature and high pressure into a rotating motion. This article describes the common features of all types. The main types are: the internal combustion engine, used extensively in motor vehicles; the steam engine, the mainstay of the Industrial Revolution; and the Stirling engine for niche applications. Internal combustion engines are further classified in two ways: either a spark-ignition (SI) engine, where the spark plug initiates the combustion; or a compression-ignition (CI) engine, where the air within the cylinder is compressed, thus heating it, so that the heated air ignites fuel that is injected then or earlier.

<span class="mw-page-title-main">V6 engine</span> Piston engine with six cylinders in a "V" configuration

A V6 engine is a six-cylinder piston engine where the cylinders share a common crankshaft and are arranged in a V configuration.

<span class="mw-page-title-main">V4 engine</span> Piston engine with four cylinders in "V" configuration

A V4 engine is a four-cylinder piston engine where the cylinders share a common crankshaft and are arranged in a V configuration.

<span class="mw-page-title-main">Flat-twin engine</span> Piston engine with two cylinders in opposing directions

A flat-twin engine is a two-cylinder internal combustion engine with the cylinders on opposite sides of the crankshaft. The most common type of flat-twin engine is the boxer-twin engine, where both pistons move inwards and outwards at the same time.

<span class="mw-page-title-main">Flat-four engine</span> Horizontally opposed four-cylinder piston engine

A flat-four engine, also known as a horizontally opposed-four engine or boxer engine, is a four-cylinder piston engine with two banks of cylinders lying on opposite sides of a common crankshaft. The most common type of flat-four engine is the boxer-four engine, each pair of opposed pistons moves inwards and outwards at the same time.

<span class="mw-page-title-main">Straight-twin engine</span> Inline piston engine with two cylinders

A straight-twin engine, also known as an inline-twin, vertical-twin, or parallel-twin, is a two-cylinder piston engine whose cylinders are arranged in a line along a common crankshaft.

<span class="mw-page-title-main">Straight-four engine</span> Inline piston engine with four cylinders

A straight-four engine is a four-cylinder piston engine where cylinders are arranged in a line along a common crankshaft.

<span class="mw-page-title-main">Straight-three engine</span> Type of engine

A straight-three engine is a three-cylinder piston engine where cylinders are arranged in a line along a common crankshaft.

<span class="mw-page-title-main">Motorcycle engine</span> Engine that powers a motorcycle

A motorcycle engine is an engine that powers a motorcycle. Motorcycle engines are typically two-stroke or four-stroke internal combustion engines, but other engine types, such as Wankels and electric motors, have been used.

<span class="mw-page-title-main">Honda CRF series</span> Motorcycle

The Honda CRF series is a line of four-stroke motocross, trail, and dual sport motorcycles manufactured and marketed by Honda.

<span class="mw-page-title-main">Villiers Engineering</span> Historical motorcycle manufacturer

Villiers Engineering was a manufacturer of motorcycles and cycle parts, and an engineering company based in Villiers Street, Wolverhampton, England.

<span class="mw-page-title-main">Harley-Davidson Twin Cam engine</span> American motorcycle engine

The Harley-Davidson Twin Cam are motorcycle engines made by Harley-Davidson from 1998 to 2017. Although these engines differed significantly from the Evolution engine, which in turn was derived from the series of single camshaft, overhead valve motors that were first released in 1936, they share a number of characteristics with nearly all previous Harley-Davidson engines. Both engines have two cylinders in a V-twin configuration at 45°, are air-cooled, and activate valves with push-rods. The crankshafts have a single pin with a knife and fork arrangement for the connecting rods. These are sandwiched between a pair of flywheels.

<span class="mw-page-title-main">Yamaha WR450F</span> Type of motorcycle

The Yamaha WR450F is an off-road motorcycle made by Yamaha Motor Company. It currently has a 450 cc (27 cu in) liquid-cooled single-cylinder engine. First offered in 1998 at 400cc, it shared many components and design concepts with the YZ400F motocross model. It is basically the racing YZ450F detuned slightly for more controllable power, with a headlight and lighting coil, softer suspension, a kickstand, lower noise specifications, larger radiators and lower emissions. The WR in the name indicates a wide-ratio gear box common to most enduro or trail bikes and stands in contrast to the close-ratio gearbox essential to a motocross racer. Over the years the WR has benefited from the advances made in the YZ motocross version gaining displacement and advancements such as an aluminum frame and improved suspension. Over much of its life the weight of the WR450F has remained fairly constant ranging from 244 to 249 pounds dry weight.

Motorcycle components and systems for a motorcycle are engineered, manufactured, and assembled in order to produce motorcycle models with the desired performance, aesthetics, and cost. The key components of modern motorcycles are presented below.

<span class="mw-page-title-main">Ducati Supermono</span> Type of motorcycle

The Ducati Supermono is a lightweight, single-cylinder racing motorcycle made by Ducati and named after the Supermono racing class. 65 Supermonos were built by Ducati between 1993 and 1995.

<span class="mw-page-title-main">Split-single engine</span> Type of two-stroke internal combustion engine

In internal combustion engines, a split-single design is a type of two-stroke where two cylinders share a single combustion chamber.

<span class="mw-page-title-main">Scooter (motorcycle)</span> Low-speed motorcycle

A scooter is a motorcycle with an underbone or step-through frame, a seat, a transmission that shifts without the operator having to operate a clutch lever, a platform for the rider's feet, and with a method of operation that emphasizes comfort and fuel economy. Elements of scooter design were present in some of the earliest motorcycles, and motor scooters have been made since at least 1914. More recently, scooters have evolved to include scooters exceeding 250cc classified as Maxi-scooters.

<span class="mw-page-title-main">Honda NC700D Integra</span> Type of motorcycle

The Honda NC700D/NC750D Integra is a motorcycle/scooter hybrid made by Honda since 2012. Known internally as the RC62, the Integra was originally unveiled as the New Mid Concept in 2010, before being presented in production form at EICMA 2011 in Milan. The Integra shares a platform with two motorcycle variants, the NC700S (RC61) and the NC700X (RC63). All three variants are powered by a 670 cc engine derived from the unit used in the Honda Fit automobile. The Integra will be available with two different power outputs, one version develops a peak power output of 38.1 kW (51.1 hp) at 6,250 rpm and 62 N⋅m (46 lb⋅ft) of torque at 4,750 rpm, while the other has a lower output of 35 kW (47 hp) and 60 N⋅m (44 lb⋅ft) to meet 2013 A2 European licensing regulations.

<span class="mw-page-title-main">Suzuki A100</span> Japanese motorcycle made beginning 1966

The Suzuki A100 is a Japanese motorcycle from the Suzuki Motor Corporation with production starting in 1966.Similar models were produced by Yamaha and Kawasaki with the YB100 & KH100 models, also with a single-cylinder two-stroke engine and rotary valve being examples.

The Ducati 100 Scrambler is an on/off road 98 cc (6.0 cu in) single cylinder two stroke motorcycle produced by the Italian manufacturer Ducati in 1970 and 1971. The model was produced to take advantage of the dirt bike craze in Italy at the time. The model used many parts from existing models, keeping R&D costs down. A smaller engined version, the 50 Scrambler, was also produced. The model did not sell well and was soon dropped.

References

  1. "Single Cylinder Engines". TheBikeMarket. Archived from the original on 2019-12-17.
  2. "How to Balancing a Single Cylinder Engine Crankshaft and Piston/Connecting Rod Assembly and Flywheel to Reduce Dangerous Vibration". www.gardentractorpullingtips.com. Retrieved 10 July 2019.
  3. "Engine Science: The Balancing Act of Single Cylinder Engines". www.isavetractors.com. Retrieved 10 July 2019.
  4. Methods of Balancing Single Cylinder Engines. Joseph R. Harkness. SAE Transactions. Vol. 77, Section 3: Papers 680436–680591 (1968), pp. 2329-2338
  5. Suzuki's Supermono Engine Design. A second con-rod without a piston. Ben Purvis. April 26, 2019
  6. "5 of the funkiest single-cylinder street bikes". www.motorcyclenews.com. 5 March 2009. Retrieved 7 July 2019.
  7. "The Single Life: 6 of the best thumpers". www.bennetts.co.uk. Retrieved 7 July 2019.
  8. "The 16 Best Retro Motorcycles Make Bikes Great, Again". www.thecoolist.com. 9 August 2016. Retrieved 7 July 2019.
  9. "How Car Engines Work". www.howstuffworks.com. 5 April 2000. Retrieved 10 July 2019.
  10. "The Lanz Bulldog". www.gasenginemagazine.com. December 1988. Retrieved 10 July 2019.
  11. "690 Duke: The essence of motorcycling". Archived from the original on 2012-06-12. Retrieved 2012-06-01.
  12. David Blasco. "Royal Enfield Motorcycles". Royalenfields.com. Archived from the original on 2011-12-07. Retrieved 2011-12-06.