How a Car Engine Works

Inside the engine there is a complex process taking place many times a minute as you drive down the road. It is fast and furiously having one explosion after another that is propelling your car or truck down the road by simple pressures of your foot on the accelerator pedal. It works like this:

• There is first the intake stroke. As the piston goes down the cylinder it draws in the air and fuel mixture. With the piston at the bottom the intake valve closes which traps the mixture of fuel and air in the cylinder.


• Now the piston will push up in the cylinder, which will highly compress the air and fuel mix at a rate of between 8:1 to 10:1 (basically making the mix about one tenth its original size).


• When the piston gets to the top the spark plug will fire and ignite the compressed air and fuel mix which makes a very powerful explosion. This will push the piston back down the cylinder providing power to the crankshaft that is hooked to the drive train propelling the vehicle. In a typical 8-cylinder engine this takes place at a slightly different time for each piston. By the time the crankshaft has made two revolutions each cylinder in the engine will have completed one full power stroke.


• When the piston hits the bottom of the cylinder the exhaust valve will open and permit the used gas from the explosion to be sent out of the system through the exhaust piping. If you think about your exhaust this is why there has to be a muffler on it to muffle the loud explosions that are occurring every few seconds as you speed down the road. Once the exhaust has been expelled it closes the exhaust valve and the four-stroke process starts all over again until the engine is turned off again.


• As all this is taking place the oil is being pumped under pressure into the engine to lubricate all its moving parts and the cooling system is pumping coolant into the engine through ports provided for keeping the engine cool as it goes through this process.