List of motorcycles by type of engine

Content sourced from Wikipedia, licensed under CC BY-SA 3.0.

Motorcycles can be grouped by engine type, including how many cylinders and how the engine is laid out. Here’s a short, easy guide to common layouts and notable designs.

Engine layouts
- Transverse vs. longitudinal: A transverse engine has its main axis running left to right across the bike, with the crankshaft orientation perpendicular to the direction of travel. A longitudinal engine has its axis front to back, parallel to the direction of travel.
- V-twins and axis naming: Some people describe engine orientation using the engine’s widest dimension rather than the crankshaft line. By this convention, a V-twin like in the Honda CX series is called transverse, while many Harley‑Davidsons are called longitudinal.

Special engine designs
- Split-single (twingle): two cylinders share one combustion chamber. Also known as parallel-twin, inline-twin, vertical-twin, straight-two, or inline-two.
- Tandem twin: two cranks geared together, effectively a pair of geared singles. Mostly used for two-stroke racers.
- Wankel engine (rotary): an internal combustion engine that uses a rotating design rather than pistons.
- Radial engine: cylinders arranged around a central crankcase, with the crankshaft stationary and the engine rotating around it. This was an early design.
- Four-cylinder designs: many models exist; this is just a partial list.
- Electric motorcycles: powered by batteries that drive electric motors.
- Diesel motorcycles: very few have been built due to weight and starting difficulties in cold conditions.
- Other unusual engines: only a small number of motorcycles use train-inspired or other exotic engine types.