The pump housing is made of cast aluminum and provides support and protection for inner part.
The Camshaft is supported by two taper roller bearings and driven by the engine, to work the feed pump and plungers. The Pump element, which is the most important part, consists of a plunger and cylinder, one element for each engine cylinder.
The control rack is connected to the linkage of the governor and meshed with each pinion which rotates the plunger to control the fuel delivery quantity and in the case of a special plunger, the injection timing also. The delivery valve prevents reverse flow of fuel in the high pressure pipe and dribbles from nozzle after injection.