How an Engine Works: a Simple Explanation

Posted by at 22 October 2014, at 11 : 07 AM

How an Engine Works: a Simple Explanation

The simplest way to describe how an engine works is the term suck/bang/blow. I’m going to go through and elaborate on these terms, so that you guys and girls have a better idea of what this means. Hopefully this will help make diagnostics make some sense anyway.

1) Suck: The engine sucks air in through a maze of tubes starting with an air filter box. It then leads past a sensor that measures the amount of air, the outside temperature, and even the humidity. Continuing along that path it goes into a metering device — Almost everyone looks different but they do the same thing – Meter the amount of air going into the intake. The intake is where air mixes with fuel and is sucked (hence the term) into the combustion chamber, which takes us to our next step in the process.

2) Bang: Something called a valve opens up and allows a specific amount of the mixture into the chamber. It then closes tightly forming a seal. Compressed by the upward movement of the piston, this vapor becomes a little bomb just waiting to be ignited. A time controlled high energy spark is then released from the spark plug causing this little bomb to go off, and there you have the term Bang!

3) Blow: The vapor being ignited forces the piston down and that is how power is generated, but we still have to expel the byproduct which is called exhaust gases. As the piston comes back up another valve opens allowing the gas to be pushed into the exhaust manifold where the amount of byproduct is measured and then released into the exhaust system where it is eventually blown out of the tail pipe.

This process is repeated over and over again forming what is called a four-stroke cycle. Every cylinder in the car goes through the process and that is what makes an engine keep revolving.

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