engine in a 1959
Bond Minicar Compared with multi-cylinder engines, single-cylinder engines are usually simpler and compact. 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. 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, as well as more extreme methods such as a dummy connecting rod (for example the
Ducati Supermono). 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), 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==