Definition of Cylinder (engine)

A cylinder is the central working part of a reciprocating engine, the space in which a piston travels. Multiple cylinders are commonly arranged side by side in a bank, or engine block, which is typically cast from aluminum or iron before precision features are machined into it. The cylinders may then be lined with sleeves or liners of some harder metal, or given a wear-resistant coating such as Nikasil. Ceramic linings have also been tried, so far unsuccessfully, except with low-speed "oilless" steam engines.[1] A cylinder's displacement, or swept volume, is its cross-sectional area (the square of half the bore times pi ) times the distance the piston travels within the cylinder (the stroke). The engine displacement is the swept volume of one cylinder times the number of cylinders in the engine.