tweecilinder

Tweecilinder, meaning two-cylinder in Dutch and related languages, refers to mechanical devices that use two cylinders to convert energy into motion. The term is applied across machinery such as internal combustion engines, steam engines, and hydraulic or pneumatic pumps, and it covers several cylinder layouts that place two cylinders in the same machine.

Common configurations include inline two-cylinder arrangements, where the two cylinders line up along the crankshaft; parallel twins, often used in motorcycles and light automobiles; and V-twin configurations, where the two cylinders are set at an angle to form a V shape. There are also less common layouts such as opposed-piston designs, where pistons operate in opposing motion within a shared space. The choice of arrangement affects balance, vibration, width, cooling, and the firing order of the engine or pump.

Historically, twin-cylinder layouts were widely used in early steam and internal combustion engines to improve smoothness and torque without the complexity of more cylinders. In modern engineering, tweecilinder designs remain common in lightweight motorcycles, small cars, and various stationary engines, valued for their simplicity, compact size, and ease of maintenance.

Advantages of a tweecilinder design include smoother operation compared with a single-cylinder setup and generally lower production costs than multi-cylinder configurations. Limitations can include reduced peak power compared with larger engines, greater width in certain layouts, and more complex balancing requirements to minimize vibrations.

See also: two-cylinder engines, inline-two, V-twin, parallel twin.