A major upgrade was started in 1940 in order to better compete with the 601, following in its footsteps with a pressurized cooling system. The resulting 211E proved to be able to run at much higher power settings without overheating, so it was quickly followed by the 211F which included a strengthened crankshaft and a more efficient supercharger. Running at 2,600 RPM the F and similar J engines delivered a much improved 1,350 hp. Further improvements to this basic line led to the 1,425 hp 211N and 1,475 hp 211P.