Engine configuration

The engine configuration describes the fundamental operating principles by which internal combustion engines are categorized. Piston engines are often categorized by their cylinder layout, valves and camshafts. Wankel engines are often categorized by the number of rotors present. Gas turbine engines are often categorized into turbojets, turbofans, turboprops and turboshafts. Piston engines are usually designed with the cylinders in lines parallel to the crankshaft. It is called a straight engine (or 'inline engine') when the cylinders arranged in a single line. Where the cylinders are arranged in two or more lines (such as in V engines or flat engines), each line of cylinders is referred to as a 'cylinder bank'. The angle between cylinder banks is called the 'bank angle'. Engines with multiple banks are shorter than straight engines and can be designed to cancel out the unbalanced forces from each bank, in order to reduce the vibration. Most engines with four or less cylinders use a straight engine layout, and most engines with eight cylinders or more use a V engine layout. However, there are various exceptions to this, such as the straight-eight engines used by various luxury cars from 1919-1954, V4 engines used by some marine outboard motors, V-twin and flat-twin engines used by motorcycles and flat-four engines used by various cars. Straight engines (also known as "inline engines") have all cylinders aligned in one row along the crankshaft with no offset. When a straight engine is mounted at an angle, it is sometimes called a "slant engine". Types of straight engines include: Single cylinder Straight-2, also known as "parallel twin" Straight-3, also known as "inline-triple" Straight-4, the most common engine for cars Straight-5 Straight-6 Straight-8 V engines (also known as "Vee engines") have the cylinders aligned in two separate planes or 'banks', so that they appear to be in a "V" when viewed along the axis of the crankshaft. Types of V engines include: V2, commonly called "V-twin" V3 V4 V6 V8 V10 V12 V14 V16 V18 VR5 and VR6 engines use a narrow V angle and a single cylinder head.