What Is a Single Cylinder Engine? Definition, Meaning and Concept

A single-cylinder engine is a type of combustion engine that features only one cylinder or chamber in which a piston moves to activate combustion. This is the engine's power source, and since only one piston is doing the work, a single-cylinder engine is mostly used in smaller vehicles and tools. It can produce a relatively large amount of power given its size, but this engine isn't particularly adept at varying power output rapidly, making it less versatile for larger vehicles. These motors are lightweight and compact, making them a good choice for power tools such as weed killers.

The disadvantages of a single cylinder engine include the vibration that the engine is known to produce, as well as the lower power output. Vibration occurs for various reasons; Chief among them is the weight of the rotating parts. Since only one cylinder is used for power output, many of the rotating components have to be extra strong to withstand the stress of operation. This means that the parts can be quite heavy, much heavier than their counterparts in two and four cylinder engines. This rotational weight can cause vibrations as the piston is activated, which is not a huge disadvantage in small motors used for brushcutters, chain saws, etc. It can be a problem on this type of engine mounted on a motorcycle or moped.

One of the biggest advantages of a single cylinder engine is the cost of production. Since the engine is relatively small and does not have multiple combustion chambers, the engine can be built easily and cheaply, reducing the cost of this effective engine style. Therefore, these engines are common in small, low-end motorcycles, mopeds, go-karts, and lawnmowers. The motor is also lightweight in most cases, making it easy to manipulate on handheld yard or garden machinery.

Early motorcycle models used single-cylinder engine designs as their power source, although vibration problems made the engine a poor choice, especially compared to two- and four-cylinder engines. To counteract vibration problems, some motors were fitted with balances intended to stabilize the vibratory motors, and these worked well, up to a point. However, as motorcycles grew larger and faster, the individual cylinders were replaced by larger engines that could power the machine more effectively. Cars have also used single-cylinder engines in the past, but four-, six-, and eight-cylinder engines are much more common.