Four Stroke Engine at Work

I found this video of a running 4-stroke single engine with a transparent piston bore. I know how the four-stroke cycle works, but this blew my mind!

For those who haven't witnessed this it's worth a look. Frankly, it was a bit scary to think that all that stuff is going on while I'm enjoying my ride...twice!

It's a long video with no commentary so I found myself skipping to the action bits.

https://www.youtube.com/watch?v=nvMcFQqhbpM