The Elements Of Combustion

Nov 06, 2021

A customer has his car towed into a repair shop because it will not run. He turns the key and it cranks, "Ahahrharharharharhharharharh." And it may fire up for a second but it doesn't run. And the mechanic says "Hmm, I guess I'll have to check to see if it has a spark."

And he checks for spark. And indeed, it has a spark. He checks to see if it has gas. In fact, the car has a throttle body injection and he cranks it and he sees gasoline. He has all the ingredients for combustion! He has compression, he has whatever you call it when you rub the two sticks together. And yet the thing won't start because he is missing something. He is missing one of the essential ingredients for making the engine run.

So he takes out one of the spark plugs. I don't know why he does this, but he just takes the spark plug out, turns the key, and it starts. Now what, pray to tell, prompted him to try this?

If you know what prompted him to remove the spark plug and why it wouldn't start in the first place, write us!


The ingredient that was missing was exhaust.

Pons and Fleischmann discovered this the laboratory. In order for the engine to work it must exhaust its exhaust.

And if it doesn't, it stays in the cylinders and there's no room for a fresh charge. So what was happening in this case is that the exhaust system was plugged up solid, so that when a piston was trying to suck in a fresh mixture, it couldn't because there was exhaust present. And when he took out one of the spark plugs, he allowed the exhaust to sneak out through that cylinder.

Every time that exhaust valve opened it acted like the muffler exactly. The exhaust that was trying to go out the tailpipe instead came out through that spark plug hole. And of course the engine ran loudly. But it indeed ran!

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