 A turbocharged four stroke V12 with a bore and stroke developing 1,500 (later 1,600) hp at 1,000 rpm, it had a smaller cylinder, higher cylinder speed design than the 539 used in the RS-1.Production of the RS-2 was delayed several months while Alco worked out the new four pipe divided low rise manifold for the GE constant pressure RD-1 turbocharger.The 244 engine was not a reliable design, however, and was replaced in less than ten years by the Alco 251 engine.