valve timing diagram and port timing diagram

Valve timing diagram and Port timing diagram

Valve timing diagram:

The Valve timing diagram is used to represent the opening and closing of valves at the time of  operation is known as valve timing diagram.
Valve timing diagram explains about the working of valves in the  four stroke engine. Suction and Exhaust stroke are also included init. This diagram helps to find the angle of inlet valves and outlet valve openings. And it also clearly explains about the position of piston at the time of valve opens.
Before reaching the piston to the top dead center of the cylinder the inlet valve opens and the degree of crank about 10°-30°. and the Outlet Valve gets opened before the piston reaches to the Bottom Dead Center and the angle of crank is about 30°-40°. The compression ratio of valve timing diagram is 7:1 to 10:1

Port timing diagram:

The port timing diagram representing the opening and closing of Inlet and Outlet ports at the time of  operation, which is explained along with the representation to crank rotation is known as port timing diagram.
Port timing diagram explains about the working of ports present in two stroke engine, in this it does not contains suction and exhaust stroke. The Inlet port gets opened when the piston reaches to the Top dead center at the crank angle of 20° and Outlet port opens before the piston reaches to the Bottom dead center at the crank angle of  50°. In this the compression ratio is 11:1 to 22:1