A single cylinder engine is the most basic piston engine configuration of an internal combustion engine. It is often seen on motorcycles, Auto rickshaws, motor scooters, Mopeds, dirt bikes, go-karts, radio-controlled models and has many uses in portable tools and garden machinery. It has been used in cars and tractors.



BMW R27 single-cylinder motorcycle engine

Single cylinder engines are simple and compact, and will often deliver the maximum power possible within a given envelope. Cooling is simpler than with multiple cylinders, potentially saving further weight, especially if air-cooling can be used.

Single-cylinder engines require more flywheel effect than multi-cylinder engines and the rotating mass is relatively large, restricting acceleration and sharp changes of speed. In the basic arrangement they are prone to vibration - though in some cases it may be possible to control this with balance shafts.

Pros and cons Edit

Single cylinder engines are simple and economical in construction. The vibration they generate is acceptable in many applications while less acceptable in others. Counter-balance shafts and counterweights can be fitted but such complexities tend to counter the previously listed advantages.

Components such as the crankshaft of a single cylinder engine have to be nearly as strong as that in a multi-cylinder engine of the same capacity per cylinder, meaning that some parts are effectively four times heavier than they need to be for the total displacement of the engine. The single cylinder engine will almost inevitably develop a lower power to weight ratio than a multi-cylinder engine of similar technology. This can be a disadvantage in mobile operations, although it is of little significance in others and in most stationary applications.



Motorbike Horex "Regina" with one-cylinder-four-stroke-engine

Early motorcycles, automobiles, tractors and other applications such as marine engines all tended to be single cylinder. The configuration remains in widespread use in Auto rickshaws, motor scooters, Mopeds, dirt bikes, go-karts, radio-controlled models and is almost exclusively used in portable tools, like chainsaws and strimmers, along with garden machinery such as lawn mowers.

The single cylinder design was common on early steam engines before they whent to the twin cylinder compound design to get more power out of the steam by using it twice by with a high and a low pressure cylinder, coupled together.

The single cylinder type engine was popular on the early 1900s for Stationary engines to power static machinery before the electric motor took over after the electricity grid reach rural areas. Early tractors were often also based on single cylinder engines as they were simple er with less parts than a multi-cylinder design engine. design with pistons of up to 12" (300mm) diameter and an engine capacity of several litres were not uncommon. Makes such a John Deere, Lanz and Marshall all built tractor into the 1950s with a single cylinder engine.

Early single cylinder engines were often semi-diesels (oil engines) were heat was applied to a combustion chamber to achieve ignition as the compression was not suffient to cause ignition as used in a 'full' diesel. Many single-cylinder engines built by Lister (or copies) are still in use today in remote parts of the world for driving pumps and generators.

Larger single cylinder engines were used in pumping stations and ships. these were of a slow reving design that lugged away rather the high speed running designs of multi-cylinder engines. Later ships engines often consist of several single cylinder units bolted together in series. (often these could still work with one or more cylinders out of action)

The best selling motor-vehicle of the world, the Honda Super Cub, has a very fuel-efficient 49cc single cylinder engine and big-diameter 17inch-wheels (rolls smoother over obstacles).[1]

Some motorcycles with strong single-cylinder-engines are available today. There are sportbikes like the KTM 690 Duke R[2][3][4] which has 70hp-690cc-single-cylinder-engine and reaches 125mph (200km/h) with a curb weight of only 150kg, dual-sport motorcycles like the BMW G650GS[5], as well as classics like the Royal-Enfield 500 Bullet with a long-stroke single-cylinder-engine.[6]

Nearly all Auto rickshaws have very fuel-efficient single-cylinder-engines. Typical mileage for an Indian-made auto rickshaw is around 35 kilometers per liter of petrol (about 2.9 L per 100 km, or 82 miles per gallon [United States (wet measure), 100 miles per gallon Imperial (United Kingdom, Canada)].[7]

Racing classesEdit




Notable products with single cylinder enginesEdit

Hornsby-Ackroyd tractor of 1896 at Newby 09 - IMG 2188

Early single cylinder tractor by Richard Hornsby

See alsoEdit


External linksEdit

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