A Four Stroke Engine

To start a running version of the the Four Stroke Engine click this button:

This program simulates how a four stroke engine works. The piston is connected with a crankshaft. The crankshaft in turn, turns the car's gears which turns the wheels. I will give a short discription of the four steps (or strokes). A kickstarter or an electrical starter helps to initiate the following procedure:


As the piston starts going down, the inlet valve is opened (mechanically opened by the turning of the crank-shaft). A mixture of air and gas is sucked in. As it reaches the bottom, the valve closes.


Then the piston starts going up, caused by the force of the turning crankshaft. When it reaches the top, the air/gas mixture reaches a certain compression which is highly explosive.


At this point, the electric circuit connected to the spark plug is turned on (driven mechanically by the position of the crank shaft. The spark plug causes a spark in the dense mixture of air and gas. The spark starts the explosion in the cylinder on top of the piston. This expansion caused by the explosion pushes the piston down. This force turns the crank-shaft around. 


As the piston goes up again, the outlet valve opens (being driven mechanically. The used air (smoke) from the explosion escapes through the outlet valve. As the piston reaches the top, the outlet valve closes. The cycle is then repeated.


Friction between the piston and the cylinder is not taken into account. The space when the piston is at its max height and the cylinder top is not realistic. If it was realisticlly drawn, the space would not be seen. Before I wrote this program, I knew nothing about how a four stroke engine worked. I will include also some questions , that I had while working on this program.