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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 to an equivalent inline configuration.
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 marine racing engine – the first V12 engine produced for any purpose.1
Usually, each pair of corresponding pistons from each bank of cylinders share one crank pin on the crankshaft, either by master/slave rods or by two ordinary connecting rods side by side. Some authoritieswho? regard this as a distinguishing feature of a true Vee engine, and divide flat engines into boxer engines which do not share crank pins in this way, and 180° engines which do.citation needed On the other hand, some important V-twin engine designs have two-pin cranks.
Various cylinder bank angles of Vee are used in different engines; depending on the number of cylinders, there may be angles that work better than others for stability. Very narrow angles of Vee combine some of the advantages of the Vee engine and the straight engine (primarily in the form of compactness) as well as disadvantages; the concept is an old one pioneered by Lancia, but recently reworked by Volkswagen Group.
Some Vee configurations are well-balanced and smooth, while others are less smoothly running than their equivalent straight counterparts.citation needed With an optimal angle (22.5°,45°,67.5°,90°,112.5°,135° or 157.5° for two-stroke; 45°, 90° or 135° for 4 stroke), V16s have evenly spaced firings and exceptional balance. V12s, being in effect two straight-6 engines married together, have even firing and very good balance when the V-angle is 60° or 120° for 4-stroke (30°,60°,90°,120° or 150° for 2-stroke). Others, such as the V2, V4, V6, flatplane V8, and V10, show increased vibration and generally require balance shafts.
Certain types of Vee engine have been built as inverted engines, most commonly for aircraft. Advantages include better visibility in a single-engined airplane, and lower centre of gravity. Examples include World War II German Daimler-Benz DB 601 and Jumo engines.
It is common practice for Vee engines to be described with "V#" notation, where # is how many cylinders it has:
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