Cummins' times with the engine company continued to be tumultuous even after this success, but money was being made. Cummins' first successful engine design, the Model F [(1924)], was originally used for marine applications, but came to be used in other applications. In 1931 Cummins entered the Indianapolis 500 with a self-built (3,389 pound, 361 cubic-inch) four cylinder, three-valve, , Model U marine diesel that he installed into Model A Duesenberg. The Cummins Duesy averaged and completed the race on 1 tank of fuel, without any pit stops.