Time for a little aviation input. If the DC-3 was the airplane that made the early airline business successful, and it was, here's the engine that made them all fly. This engine made trans-continental flight in the USA practical. With only three (3) refueling stops, a DC-3 could cross the US from west to east in 15 hours. Going the other way (east to west) took 17 hours due to prevailing headwinds. THE ENGINE: Wright R-1820 Cyclone 9 Wright merged with Curtiss in 1929 and recovered from the loss of Rentschler and other engineering staff. In 1932, the R-1750 was developed to a capacity of 1823 cu in. This was the F model Cyclone, designated R-1820. This engine introduced a forged aluminium crankcase and was developed through the 1930s to reach 890 hp. It used a bought-in General Electric supercharger and Wright concluded that this feature limited the potential power output of the engine. For the next development, the G-Series of 1937, Wright developed its own single-speed supercharger. The G-series was developed to deliver 1200 hp at 2500 rpm and made up the bulk of R-1820 Cyclone production during World War 2. The final phase of development of the single row radial design was the H-Series at 1350 hp. The good old days(?). Bill