Piston Timing Diagram. The inlet valve opens at a and the suction takes place from a to b. This is to ensure that the fresh charge enters the cylinder as soon the piston as soon as the piston starts to move down.
Valve overlap in valve timing diagram valve overlap is the short period of time in which both the inlet and the exhaust valve is open. Piston moves from the top dead centre tdc to bottom dead centre bdc. Valve timing diagram the above processes will be operated with the sequence of operations of the valves in the four stroke engine.
This is called the valve timing diagram.
The extreme position of the piston at the bottom of the cylinder is called bottom dead centre bdc. At b the inlet valve closes and the compression takes place from b to c. This relation between the valve opening timings to the piston moves from the top dead centre tdc to the bottom dead centre bdc can be represented on a circle. Engine valve timing diagram the inlet valve usually opens few degrees before the piston reaches tdc in its exhaust stroke.