A V engine, or Vee engine is a common configuration for an internal combustion engine. The cylinders and pistons are aligned, in two separate planes or 'banks', so that they appear to be in a "V" when viewed along the axis of the crankshaft. The Vee configuration generally reduces the overall engine length, height and weight compared with an equivalent inline configuration.
History
The first V-type engine, a 2-cylinder vee twin, was built in 1889 by Daimler, to a design by Wilhelm Maybach. By 1903 V8 engines were being produced for motor boat racing by the Société Antoinette to designs by Léon Levavasseur, building on experience gained with in-line four-cylinder engines. In 1904, the Putney Motor Works completed a new V12, 150bhp 18.4 litre engine – the first V12 engine produced for any purpose. This one was manufactured for two Russian brothers making a dirigible. They ran out of money and Commander May bought it on a sale or return basis for Motor boat racing, having some moderate success in 1908. The engine was exposed and the hot coil ignition created misfiring on becoming wet with the spray. Robert Bosch supplied the very first magnetos and the problem was solved.
Characteristics
Compared with an equivalent inline engine, a V engine has a shorter length but is wider. This effect increases with the number of cylinders in the engine; the length different between a V-twin and straight-twin engines might be insignificant, however V8 engines are have a significantly smaller length than straight-eight engines. Compared with the less common flat engine, a V engine is narrower, taller and has a higher center of mass. The "V-angle" between the cylinder banks varies significantly between engines. Some engines have used a V-angle of 180 degrees, such as several Ferrari V12 engines. At the other end of the scale, the 1922-1976 Lancia V4 engine and the 1991-present Volkswagen VR6 engine use V-angles as small as 10 degrees, along with a single cylinder head used by both banks of cylinders. The engine balance of a V12 engines is that of perfect primary and secondary balance. For V engines with fewer cylinders, the engine balance will depend on factors such as the firing interval, crankshaft counterweights and whether balancer shafts are present. The crankpins on a V engine are usually shared by two cylinders from opposing banks, with an offset between the two cylinders. Alternative configurations are separate crankpins per cylinder or articulated connecting rods.
Inverted engines
Certain types of Vee engine have been built as inverted engines, most commonly for aircraft. Advantages include better visibility in a single-engined airplane, higher thrust line, and resultant increased ground clearance for the propeller. Examples include the British de Havilland Gipsy Major, German Daimler-Benz DB 601 and American Ranger L-440piston engines.
Specific configurations
It is common practice for Vee engines to be described with "V#" notation, where # is how many cylinders it has:
