Before discussing about the four-step cycle diesel engine it should be agreed in advance some of the terminology / terms that will be widely used.
1) Top dead center / top dead point: Position the top of the piston movement.
2) Bottom dead center / bottom dead point: Position the bottom of the piston movement.
3) Bore: Diameter combustion chamber (combustion chamber).
4) Stroke: indicates the distance traveled by the piston to move from BDC towards TDC or otherwise.
5) Displacement: Bore x Stroke Area.
6) Compression ratio: Total volume (BDC) / compression volume (TDC).
Figure 4.1 Figure TDC and BDC
Figure 4.2 Figure Bore
Figure 4.3 Figure Stroke
Figure 4.4 Figure Displacement
Figure 4.5 GambarCompression Ratio