When you think “engine,” you probably think “power.” And when you think “power,” you probably think “big.”
We do, too, but consider tiny engines. They operate on the same principles but on a more space-efficient scale, which requires a whole different kind of engineering finesse. Tiny engines may not be as practical as their big brothers, but they’re almost always more fun. And believe us, these engines are tiny. Check them out below:

Aliaksei Zholner is terrific at making model engines. Here, he illustrates a tiny paper throttle that he can use to rev up his mini V-8 to a terrifically tiny purr. It runs on compressed air, as opposed to any form of combustible fuel, but that doesn’t make it any less impressive. 
Leslie Proper enjoys model steamboats. He has posted videos of them in action, cutting through the water just like full-scale steamboats. Here, he shows off what makes them run: six tiny, functional engines. The single-cylinder, double-acting engine is especially impressive.

Sometimes the best way to make an engine tiny is to change how the thing works. Difo Productions, an Italian YouTuber, re-created a V-6 engine but decided to bypass the traditional explosions. Working with steam instead of fuel allows Difo flexibility to make alterations like using brass tubing for airflow and aluminum for the cylinders, crankcase, and pistons. It took seven months to build, but the miniature results speak f...