Jumping the Gap - Understanding What Your Spark Plug Does

Welcome back to our series of short articles onconditions despite carbon buildup and fast moving air
automotive repairs and how to guides for the newand fuel mixtures. As your piston comes up during it's
weekend warrior auto mechanic. It's important to knowcompression stroke, the air and fuel mixtures
that these aren't written for the racing car pit crewcompress. At near the top of the compression stroke
professional. In fact, it's written for the average guyan electrical current will pass from the ignition coil,
just like yourself that really just wants to know a littlethrough the distributor and spark plug wires, and down
bit more about how his car works and maybe wouldto the plugs. At the tip of the plug, there are two
like to get his hands dirty on the weekend. In this articleelectrodes. Once the electrical current reaches the tip
I'm going to talk specifically about what a spark plugof the spark plug it has to jump a very thin gap to
does. It's important to understand this basic part ofreach the negative electrode. When it jumps the gap,
your engine so that if something goes wrong and youthe air and fuel mixture is compressed and exposed to
think it's ignition related, you have the information youthe heat and energy from the 40,000 volts or more of
need to properly understand what it should and shouldelectrical current causing it to catch on fire. This flame
not be doing.front then travels through the air and fuel mixture,
The spark plug is a pretty simple device. It's basicburning and pushing the piston downwards. Once the
purpose is to be durable enough to withstand thespark has reached the negative electrode, the spark
temperatures and forces of combustion, yet still beplug's job is done until the next compression stroke
able to conduct electricity in this high temperatureduring which the whole process repeats itself.