You might think there’s nothing refined about gasoline being pumped into your car’s engine to create big, loud, hot explosions. But one look at those gorgeous explosions and you might think these dirty gas engines are a bit more sophisticated than you gave them credit for.
That’s because gas and air don’t just get shoved into your cylinder randomly—they’re directed by the valve ports and the piston head shape to create turbulence or “swirl” so that the air and fuel can mix to optimize combustion efficiency.
Here’s a flathead engine being fed gasoline, alcohol and acetylene by YouTuber Warped Perception. Through that see-through cylinder head, you can good idea of how the air/fuel mixture moves throughout the combustion chamber, and how the flame front propagates. It’s a beautiful sight:
It looks like a fun experiment, and I do have a flathead engine sitting around.