It can be tough to visualize the inner workings of an internal combustion engine.
That process becomes much easier with this video from Matt Mikka of Warped Perspective. In it, he combines a see-through engine with a high-speed camera to record super-slow-motion footage of a four-stroke in action.
The coolest thing to me: Seeing how little gasoline is sprayed into the engine during the intake stroke. It almost looks like an accident. Compare that to later in the video, when Mikkas trades gasoline for rubbing alcohol. The stuff seemingly floods the cylinder, yet the engine runs just fine.
See the see-through engine in action in the video above. Find more of Mikka's work at YouTube.