Injection Pump
This system uses a Bosch Type A fuel injection pump. Through action of a governor and timer, the pump feeds pressurized fuel to the engine. Pump transfers fuel from the tank, through the filter, to the plunger assembly. Plunger then forces fuel, in correct amounts, to the injector nozzles.
Pump has one plunger and one delivery valve for each cylinder. An automatic timer is mounted on the drive end of pump housing. Governor is on opposite end. Pump housing contains the camshaft, tappet, plunger, control sleeve and control rack assemblies. Pump plungers have a constant stroke and are operated, through roller tappets, by a camshaft in pump assembly. Pump camshaft is driven at half engine speed by a gear meshed with engine camshaft gear. Lower end of each plunger engages fork on control rod which is connected to governor. See Fig 1.
Governor movement is transmitted to each plunger, causing them to turn in their cylinders. This turning action changes position of helical groove machined in each plunger in relation to cylinder ports. Fuel delivery is controlled by this change in groove-to-port positions.