Founded in 1925 and still active nowadays, the Pratt & Whitney Aircraft Company is one of the most important US companies in the aeronautical and aerospace sector. Its first engine, named R-1340 Wasp, was completed at the end of 1925, and became the archetypal model of a long series of engines that gained considerable commercial success all over the world thanks to their performance and high reliability. Many of them are still used today in various aircraft. In particular, the R-1830 model, developed in the early 1930s, is the most famous of the Wasp series as well as one of the most produced piston engines in the history of aviation, together with its counterpart and direct competitor, the Wright R-1820. The R-1830 engine was produced up to 1951 in over 170,000 units, that were used in numerous military and civilian aircraft. Its constructive scheme, also adopted by other companies, remained almost unchanged over the years, and allowed the development of the original project through dozens of models and various sub-types. They were subject to continuous technical updates and notable performance improvements, going from about 650 HP of the first prototypes to over 1350 hp of the latest models for the four-engine Douglas DC-4, while maintaining almost unchanged original dimensions.