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Volkswagen's VR6 engines, and the later VR5 variants, are a family of internal combustion engines, characterised by a narrow-angle (10.5° or 15°) V engine configuration. Developed by the manufacturer in the late 1980s, evolutions of these engines are still produced by them. When containing six cylinders, a VR-engine's cylinder block consists of two cylinder banks (left: 1-3-5; right: 2-4-6) while there is only a single cylinder head covering both rows of cylinders. ==Description== The name VR6 comes from a combination of V engine (German: V-Motor), and the German word "Reihenmotor" (meaning "inline engine" or "straight engine") - and so is described as a "Vee-Inline engine" (VR-Motor). It shares a common cylinder head for the two offset banks of cylinders. It has a specific sound that is unique and different than either inline or "V" engines. The engine is currently in use in a variety of VW models, one such example is the Volkswagen Passat NMS.〔:de:VR-Motor〕 This engine configuration was also adopted for the Horex VR6 Motorbike. The Volkswagen VR6 was specifically designed for transverse engine installations in front-wheel drive vehicles. The narrow angle of 15° between the two 'rows' in the VR6 engine is a more compact size than a wider angle V6 design. This made it possible for Volkswagen to install six-cylinder engines in existing four-cylinder cars. The wider configuration of a wider angle V6 engine would have required an extensive redesign of the vehicles to enlarge the engine compartment. The VR6 is also able to use the firing order of a straight-six engine. The narrow angle between cylinders allows the use of just one cylinder head - whereas wider angle Vee engines require two separate cylinder heads. This arrangement also allows for two overhead camshafts to drive all the valves. This simplifies engine construction and reduces costs. In early 12 valve VR6 engines, there were two overhead camshafts with six cam lobes on each. The forward camshaft has three intake valve lobes and three exhaust valve lobes to control the frontmost three cylinders. The rear camshaft is designed the same way, but controls the rearmost three cylinders. The operating principle of this design is most similar to a single overhead camshaft (SOHC) design. Later 24 valve VR6 engines still had two overhead camshafts, but with 12 cam lobes each. However, the operation of the camshafts in the 24 valve engine is different from that of the earlier 12 valve engine, in that the front camshaft only operates the intake valves, and the rear camshaft only operates the exhaust valves. The operating principle of this design is most similar to a double overhead camshaft (DOHC) design... There are several different variants of the VR6 engine. The original VR6 engine displaced 2.8 litres and featured a 12 valve design (two valves per cylinder). These engines produced a DIN-rated power output of , and of torque. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「VR6 engine」の詳細全文を読む スポンサード リンク
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