Two Stroke Engine In two stroke engine, instead of valves ports are provided, these are opened and closed by the moving piston. Through the inlet port, the mixture of air and fuel is taken into the crank case of the engine cylinder and through the transfer port the mixture enters the engine cylinder from the crank case. The exhaust ports serve the purpose of exhausting the gases from the engine cylinder. These ports are more than one in number and are arranged circumferentially.
A mixture of air fuel enters the cylinder through the transfer ports and drives the burnt gases from the previous stroke before it. As the piston begins to move upwards fresh charge passes into the engine cylinder. For the remainder of upward stroke the charge taken in the engine cylinder is compressed after the piston has covered the transfer and exhaust ports. During the same time mixture of air and fuel is taken into the crank case. When the piston reaches the end of its stroke, the charge is ignited, which exerts pressure on top of the piston. During this period, first of all exhaust ports are uncovered by the piston and so the exhaust gases leave the cylinder. The downward movement of the piston causes the compression of the charge taken into the crank case of the cylinder. When the piston reaches the end of the downward stroke. The cycle repeats.
