To understand how a diesel engine operates, an understanding of the major components and how they work together is necessary. Figure below is an example of a medium-sized, four-stroke, supercharged, diesel engine with inlet ports and exhaust valves and provides a cross section of a similarly sized V-type diesel engine.
Cutaway of a GM V-16 Four-Stroke Supercharged Diesel Engine
Cross Section of a V-type Four Stroke Diesel Engine