Title: Why Do Aircraft Engines Have Two Spark Plugs Per Cylinder? | Boldmethod
Headings: Why Do Aircraft Engines Have Two Spark Plugs Per Cylinder?
Why Do Aircraft Engines Have Two Spark Plugs Per Cylinder?
1) Reliability
2) More Power
3) Even Combustion
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Spark Plug Fouling
AA1Car.com
Two Really Is Better Than One
Colin Cutler
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Content: If you only had one spark plug per cylinder, you would lose more than 25% of your power, if you were flying a 4-cylinder engine. And if you've ever flown a small single-engine plane, you know that a power decrease like that could mean the difference between cruising and not being able to maintain altitude. By having a dual ignition system with two spark plugs, none of this is a problem. If you have a magneto fail, you'll probably see a slight drop in engine RPM, but the other magneto, and the spark plugs that it's connected to, will keep firing on all cylinders. And if you simply have a spark plug fail? The same thing happens. 2) More Power
There's another major benefit to having two spark plugs per engine, and that is power. When two spark plugs fire at the same time in a cylinder, you get something called a "twin flame front". That means that instead of your fuel-air mixture igniting from one point in the cylinder, it ignites from two separate locations on opposite sides of the cylinder. This is important for two reasons: