A V-twin engine, also called a V2 engine, is a two-cylinder piston engine where the cylinders are arranged in a V configuration and share a common crankshaft.

A V engine, sometimes called a Vee engine, is a common configuration for internal combustion engines. It consists of two cylinder banks—usually with the same number of cylinders in each bank—connected to a common crankshaft. These cylinder banks are arranged at an angle to each other, so that the banks form a "V" shape when viewed from the front of the engine.