Answer for How to explain the working of a four-stroke diesel engine

In a diesel engine, the engine cycle is completed after the four strokes are performed in the following ways:
Suction Stroke: The inlet valve remains open. Piston moves from T.D.C. towards B.D.C. When the piston goes down, in the empty spaces in the cylinder, clean air is filled.
Compression Stroke: The inlet valve is closed. Piston moves from B.D.C. towards T.D.C. and the cylinder’s air gets compressed in the combustion chamber at a high ratio. Because of this high pressure the temperature of air is highly increased. , Automobile Engineering
Power or Firing Stroke : Diesel is sprayed in the compressed hot air with air injector, when the diesel comes into contact with the hot air it burns and gases spread in the cylinder. This causes pressure on the piston and it moves from T.D.C. towards B.D.C. The jolt received by piston turns crank shaft and the flywheel in the form of power through the connecting rod. This power received by the flywheel is used for other purposes.
Exhaust Stroke : Exhaust valve remains open. Piston moves from B.D.C. towards T.D.C. The gases burnt by the pressure of the piston are released out of cylinder. In this manner, turn by turn, the four strokes are completed and engine keeps on working.