BMW worked on what was essentially an enlarged version of its highly successful BMW 801 design from the Focke-Wulf Fw 190A. This led to the 53.7-litre displacement BMW 802 in 1943, an eighteen-cylinder air-cooled radial, which nearly matched the American Duplex-Cyclone's 54.9-litre figure, but with a weight of some 1530 kilograms matching that of the 24-cylinder liquid-cooled inline DB 606; and the even larger, 83.5-litre displacement BMW 803 28-cylinder liquid-cooled radial, which from post-war statements from BMW development personnel were each considered to be "secondary priority" development programs at best.