dead center position

dead center position

dead center positionclick for a larger image
Dead center positions with piston at top dead center on the left and at bottom dead center on the right.
The position of the piston in a reciprocating engine in which the wrist pin, the crank pin, and the center of the crankshaft are all in one line. The two dead center positions are top dead center (TDC) and bottom dead center (BDC). At either of the two positions, the piston stops moving and reverses the direction of its movement.