This is the sort of thing you wish you were taught in your design and technology class back in high school. Let's ignore for a second the complexity of manufacturing the parts and putting it together correctly, or the fact the average D&T teacher probably wouldn't know the first thing about hand-crafting an engine. Instead, just marvel at the sheer awesomeness of one man's quest to construct his very own chrome baby.
You may notice there's no ignition system or fuel, so it's not an actual combustion engine. Instead, it runs on air. At the end of the video the maker, one Yesus Wilder, pumps compressed air into it and while it's not as meaty, it sure sounds like an engine to me.
The music is oddly... grandiose... considering the content of the video. Yet, it sort of works, if you can imagine there's a tiny brigade of hobbits crafting the engine instead.