The spark plug , in an engine that has spark ignition, provides the gap across which the high tension voltage jumps, creating the spark that ignites the compressed air and fuel mixture inside the combustion chamber.

Spark plug gaps differ from engine to engine; however, most gaps will fit between 0.501-2.032mm. Obviously, each engine has a different spark plug gap and so the size of the gap must be set to the engine manufacturer’s specifications. The size of the gap depends on the compression ratio of the engine, the design of the combustion chamber, and the type of ignition system.

Spark plugs are such an important part of the engine’s overall performance. Using the wrong type of plug could either damage your engine, or at the very least cause the engine to misfire and run roughly.

Spark plugs are designed so that the temperature at the firing end of the plug is high enough to burn off any of the carbon or other deposits that can otherwise build up. However, the plug must not be so hot for the heat to cause pre-ignition to occur in the combustion chamber.

Engine designers select spark plugs that will give excellent performance for every day average driving conditions. But if the engine is run under full load for a lengthy period of time, the standard plug will run too hot, causing pre-ignition to occur. Therefore, a colder plug is needed for the engine to perform correctly under such usage.

The opposite can happen to a standard plug when the engine is run too often at part-throttle position. The standard sparkplug will tend to foul up with carbon and other depository material. If the engine will be used under part-throttle for lengthy periods, a hotter spark plug needs to replace the standard spark-plug.

The ignition system must be timed precisely so that the spark occurs in the combustion chamber at the perfect moment for the engine’s requirements and demands.

For such a small device, the spark plug has a lot of responsibility for the overall efficient running and performance of a motor vehicle’s engine.We hope that helps answer the question ‘What is What is a Spark Plug?’!

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