fours, first squares then Vs, by Honda, Kawasaki, Cagiva, Suzuki, Yamaha. Kawasaki also experimented with a trapezoidal four the 602S. Yamaha made the V4 RD500LC, and Suzuki the RG400 and RG500 square four road bikes. Square four A square four is a U engine with two cylinders on each side. This configuration was used on the Ariel Square Four motorcycle from 1931 to 1959. This design was revived as a two-stroke version on some racing Suzuki models, and their subsequent road-going version the RG500. Although some racing success was achieved, the road bikes didn't sell in great numbers, and the design was phased out in favor of in-line, four-stroke designs, as at the time two-stroke engines were quickly being superseded by more economical, reliable, and emissions-friendly four-strokes. Five V5 Honda has produced five-cylinder engines for racing, the RC211V 990 cc V5. No V5 engines are currently available in commercial production motorcycles. Just prior to their collapse, BSA planned a modular family of bike engines based around a 200 cc single. The range was to include the single, a 400 cc twin, a 600 cc triple and a 1000 cc V5. None of these motorcycles reached production. Six Inline six The 1,047 cc Honda CBX was produced from 1978 to 1982. The 1,300 cc Kawasaki KZ1300 was produced from 1979 to 1989. Benelli made the 750 cc and 900 cc the Sei from 1972 to 1978. Honda made a 250 cc straight-six GP bike. The BMW K1600GT and K1600GTL, which were launched in 2011, have a transverse-mounted 1,649 cc engine. Flat 6 The six-cylinder engine is currently used by Honda in the Gold Wing, and had previously been used in the Valkyrie and the Rune, both of which were cruiser developments of the Gold Wing. V8 Galbusera built a V8 in 1938, and Moto Guzzi experimented over a period of two years with its dual-overhead-cam 500 cc V8, the Otto Cilindri, in the 1950s. Some custom and one-off motorcycles use more than six cylinders. For example, the Boss Hoss motorcycle uses (5,700 cc, 6,000 cc and 8,200 cc) Chevrolet V-8 crate motors. In 2003 Daimler-Chrysler manufactured a limited number of Tomahawk concept vehicles with a Dodge Viper V-10 engine. Australian company Drysdale have built short runs of 750 cc V8 superbikes and 1L V8 roadgoing motorcycles, both with engines specifically developed for the purpose. No major motorcycle manufacturer has used eight