What is Valve train?

Four stroke Motorcycle engines work the same way that car engines do. They consist of a piston, a cylinder block and a head; which contains the valve train. The piston moves up and down in the cylinder block, driven by explosions of a fuel-air mixture that has been ignited by a spark. The camshaft allows the valves to open and close to allow the fuel-air mixture to enter the combustion chamber. As the piston moves up and down, it turns a crankshaft, which transforms the energy from the pistons into rotary motion. The rotational force of the crankshaft is transmitted, via the transmission to the rear wheel of the motorcycle. The four strokes refer to intake, compression, combustion and exhaust strokes that occur during two crankshaft rotations per working cycle of Otto cycle and Diesel engines. Its power cycle consists of adiabatic compression, heat addition at constant volume, adiabatic expansion and rejection of heat at constant volume and characterized by four strokes, or reciprocating movements of a piston in a cylinder: 1. Intake Stroke, 2. Compression Stroke, 3. Power stroke, 4. Exhaust stroke. The cycle begins at top dead center (TDC), when the piston is furthest away from the crankshaft. On the first stroke (intake) of the piston, a mixture of fuel and air is drawn into the cylinder through the intake (inlet) port. The intake (inlet) valve (or valves) then close(s) and the following stroke (compression) compresses the fuel-air mixture.