Stephen Cox Blog Presented by McGunegill Engine Performance Triumph took the world by storm in 1938 by introducing its Speed Twin, the first of the great British parallel twin street motorcycles. But their enthusiasm – and sales – were cut short by World War II, which began the following September. Triumph engineers quickly adjusted to wartime production by re-designing the Speed Twin’s excellent 500cc power plant for military use as a portable generator. The cylinder heads and barrels were cast from aluminum and the generator’s operating temperature was kept in check by connecting an external fan to the engine’s tin, Read More