Hercules Engines

Shown:Model IXA Hercules engine used in the Plymouth and Early Silver King.

This engine could be equipped with magneto or battery ignition, and notice the Silver King cast oilpan  which is one piece from where the front end pivots on the tractor, all the way to the bellhousing. The Hercules engine was the first engine used on the Silver King. They were used from 1934 to 1941. The cylinders are cast in block with the upper half the crankcase integral. The engine used a Thermo-Siphon system, which used the difference between the temperature of the radiator and that of the engine to circulate to the water. Therefore Silver Kings with Hercules engines do not have water pumps. However Hercules did make a water pump that would  mount  in front of the magneto , and worked quite well, these pumps are rare. The Plymouth and  early Silver King used the IXA engine, then they started to use the  IXB engine which they used the most . Not many tractors had the IXB-3 engine. Some of the specifications for the engines are listed below.

Engine Data:

        Engine Model                     IXA              IXB              IXB-3           

       Bore and Stroke                 3X4             3.25X4         3.25X4   

        Piston Displacement           113               133                133

        N.A.C.C.(taxable HP)        14.4               16.9              16.9

        Actual Horsepower            20.5               24.5              25.4

        Tested at Rated RPM        1400               1400            1500

Click here to go back "Models" page.