A single cylinder engine, colloquially known as a one-lunger or thumper, is an engine configuration consisting of just one cylinder, the simplest arrangement possible for an Otto or Diesel engine. The mounting can be standing, lying or angled.

Pros and Cons

Compared to multi-cylinder engines, single cylinder engines have several advantages, primarily their simple and economical construction. Balance shafts and counterweights on the crankshaft must be used to balance the weight of reciprocating parts, and can be expensive and complicated due to the collective mass of multiple cylinders. However, components such as the crank have to be just as strong as in a four-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. This leads to the biggest downside of the single cylinder engine: it develops considerably lower power to weight ratios than a multi-cylinder of the same type.

Uses

Some early automobiles, such as the Cadillac 1906 Model K and 1907 Models L and M used single-cylinder engines [1]. Single cylinder engines were also popular at one time for marine uses (see external links, below). The first Moto Guzzi design used a horizontal single.

Today the most common configuration is the 50cc-two-stroke Otto seen in so many bikes and scooters. These vehicles allowed the first mass-motorisation in many countries. Most engines used in small portable appliances, such as chainsaws, generators and domestic lawn mowers, usually have one cylinder. Also, the one-lunger is used in working vehicles, motorsports, airplanes, and as an industrial motor.

Suzuki has produced a 652cc single cylinder 4-stroke motorcycle off and on from 1986 to current .

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

1990 Yamaha SRX400 (400 cc displacement)

1986 Suzuki LS650 'Savage' (652cc displacement)

Piston engine configurations  •  • [ e]
Straight	Single, 2, 3, 4, 5, 6, 8, 9, 10, 12, 14
Flat	2, 4, 6, 8, 10, 12, 16
V	2, 4, 5, 6, 8, 10, 12, 16, 20, 24
W	8, 12, 16, 18
Other inline	H, U, Square, VR, Opposed, X
Other	Radial, Rotary, Pistonless (Wankel)

Heat engine types/configurations using thermodynamic cycles (Power cycles)
Stroke number and stroke parting
Crower six stroke Four-stroke cycle Scuderi Split Cycle Engine One-stroke cycle Six stroke engine Two-stroke cycle
Different work volume types (incl. Pistonless rotary engine)
Britalus Rotary Engine Combustion chamber Controlled Combustion Engine Jet engine Orbital engine Piston engine Quasiturbine Rocket engine Swing-piston engine Toroidal engine Trochilic engine Tschudi engine Twingle engine Wankel engine
Different work volume ports and main forms of
Cylinder head porting D slide valve Four-stroke cycle engine valves Manifold Multi-valve Piston valve Poppet valve Rocket engine nozzles Sleeve valve
Different pistons layouts
Bourke engine Delta engine Double acting/differential cylinder Opposed piston engine Radial engine Rotary engine Single cylinder engine Stelzer engine Straight engine
Different main rotational motion mechanisms or arc to (or even almost) pistons back-and-forth.
Sector straight-line linkage [3] Connecting rod Coomber Rotary Engine [4] Crank Substitute Engine [5] Crankshaft Evans linkage [6] Cam Parallel motion Peaucellier-Lipkin linkage Piston rod QRMC Stirling/HydraLink [7] Revolving Cylinder Engine [8] Rhombic drive Scotch yoke Swashplate Swashplate engine Watt's linkage
One-way stop-and-go like rotational motion mechanisms to rotation.
Toroidal engine Trochilic engine

External links

• european supermono series
• www.suzukisavage.com active user community for the Suzuki single cylinder motorcycle
• Preston Services (Kent, UK) website, containing images of several single-cylinder marine engines for sale.
• Old Marine Engine Discussion Board