In design terms the 323 was basically a dead-end with little growth potential. By the start of the war its 1,000 hp was already at the low end of the performance scale, and use was limited to transports and bombers. In order to build a 1,500 hp-class engine Bramo started development of a two-row version of the engine as the Bramo 329, mirroring similar developments at BMW who were trying to scale up their Pratt & Whitney Hornet into the two-row BMW 139. Design of both engines was well advanced in 1939 when BMW bought Bramo, and cancelled work on the 329 to concentrate on what would become the excellent BMW 801.