What you’re seeing is the engine of a 2017 Nissan GT-R—that is, the 3.8-liter V6 24-valve twin-turbocharged engine—being hand assembled. It’s like the world’s hardest 3D puzzle that gets bigger as you’re going through it with more complicated pieces to mess up the process. The final product is a machine of beauty, 565 horsepower with 467 lb-ft of torque. This is how beasts are made.
Why do you think this is “the worlds hardest 3D puzzle”? Clearly an engine mechanic knows pretty much where every part goes, and has blueprints if they don’t know. Not only that, but they have specialized tools to make them more productive and safe, and there’s really only a few dozen parts. That doesn’t seem particularly hard.
I’m not saying it’s an easy task to build the engine, I’m just saying that claiming this is the worlds hardest 3D puzzle seems rather silly. It’s not even in the same ballpark as a 3D puzzle, much less the worlds hardest puzzle.