The info that I have is that in November 1935, Rudolph (Rudy) Daub submitted an unsolicited design for a two-row, 14-cylinder, radial engine, which would eventually become the R-2600. Wright was looking for a new engine design, but Daub was not one of the designers asked to submit a proposal. On 29 November 1935, Daub was notified that his design had won and that he was now the engine project’s head designer. Official design work on Daub’s engine was started on 1 December 1935, and the engine was first run in June 1936. Wright issued official specifications for the R-2600 on 23 September 1936. The engine completed a 150-hour endurance run in November 1936, and passed its type test on 10 June 1937. I do not know when the R-2600 was first flown, or what type of aircraft made the flight.
At the Paterson, New Jersey plant, limited production was started in February 1937, with production increasing to over 25 units per month in September 1939, over 50 units in January 1940, and nearly 100 units in June 1940. Peak R-2600 production at Paterson was in 1941 with 7,186 engines being built that year.
Production at the Lockland, Ohio plant started in June 1941, and 135 engines were built in November 1941. Peak R-2600 production occurred at Lockland in 1944 with 25,680 engines being built.
