V5 engine

A V5 engine is a five-cylinder piston engine where the cylinders share a common crankshaft and are arranged in a V configuration.

Even by contrast to the fairly rare straight-five engine, V5 engine designs are very uncommon. The first production V5 was the 1997–2007 Volkswagen Group VR5 engine. It is arguably not a true V5 engine, as all the cylinders share a single cylinder head. However, Honda produced a true V5 motorcycle racing engine, used in the RC221V.

General Motors
In the early 1980s, Oldsmobile developed a prototype 2.5 L V5 diesel engine, however it never reached production stages and the project was subsequently abandoned. The engine is based on the Oldsmobile V6 diesel engine with the fuel injection pump in the location of the "missing" sixth cylinder. A prototype engine is on display at the RE Olds Museum in Lansing, Michigan.

Volkswagen Group
The only V5 automobile engine to reach production was the 2.3 L "VR5" engine manufactured by Volkswagen from 1997 to 2006. Based on Volkswagen's VR6 engine, the VR5 was a narrow-angle engine with staggered cylinders (three cylinders on one bank and two on the other) sharing a single cylinder head. As per the VR6 engine, the angle between the banks was 15 degrees. Initial versions used 2 valves per cylinder, however, an update in 2000 resulted in a total of 4 valves per cylinder and the addition of variable valve timing.

Honda
The Honda RC211V, a MotoGP racing motorcycle which competed in the 2002–2006 seasons, used a V5 engine. The transversely-mounted 990 cc engine had three cylinders at the front, two cylinders at the rear and a V-angle of 75.5 degrees. The engine used 4 valves per cylinder.

BSA
In the last days of the BSA motorcycle manufacturer, the factory design team produced plans for a modular range of four engines, all using a 200cc cylinder. (It was planned to increase the cylinder capacity to up to 250cc in due course). The range, which never went further than the drawing board, comprised: (The company avoided the perhaps obvious 800cc straight-four option, to avoid direct competition with the major Japanese factories that already dominated the market with such machines).
 * 200cc single
 * 400cc parallel twin
 * 600cc triple
 * 1,000cc V5 muscle bike