--- title: "Watch This Air-Powered Lego Truck Run Well With a Three-Cylinder Engine" description: "It's not every day you see a remote-controlled Lego car powered by compressed air, but today is absolutely one of those days." date: "2023-01-24" modified: "2023-01-24" authors: - name: "Peter Holderith" job_title: "Contributor" link: "https://www.thedrive.com/authors/peter-holderith" url: "https://www.thedrive.com/news/watch-this-air-powered-lego-truck-run-well-with-a-three-cylinder-engine" categories: - "News" --- # Watch This Air-Powered Lego Truck Run Well With a Three-Cylinder Engine ![]() *\Brick Technology via YouTube\* Lego vehicles don't typically escape the realm of electric power, but as we've seen before, you can build [air-powered engines]() with the building blocks, and they can even do useful work. Getting them to power [a car]() is a different story. In short, you have to carry your compressed air around with you, and that's easier said than done. As usual, [Brick Technology]() has figured it out. Sure, you have to build a miniature semi-truck with a trailer consisting of two-liter bottles, but it works and works [surprisingly well](). The little truck is powered by a three-cylinder engine, which fits nicely under the hood of the completed vehicle. This proved to be the best configuration tested. Power is sent to the rear axle via a one-speed gearbox with reverse. To prevent stress on the drivetrain components, there's a neat one-way clutch on the back of the engine that allows the truck to freewheel when the engine stops abruptly. https://youtu.be/3crQ09q5Jco The entire thing is [remote-controlled](), and there's an entire ecosystem of Lego components to support this, which is pretty interesting. Likewise, it seems like there's something of a small economy of parts people use to make advanced pneumatic devices, like engines, out of Legos. If only I had this stuff as a kid. The machine comes together nicely, but it seems like it's not until late into the vehicle's construction that our friend, uhh, *Brick* realizes just how poor the energy density of compressed air is, which is why it's a semi-truck hauling around two-liter bottles. To be clear, very highly compressed air can have an energy density (by volume) in the realm of [lead-acid batteries](), but that's at, like, scuba tank pressures. Two-liter bottles can hold up to a significant amount of pressure, but not that much. ![]() ![]() ![]() With the two bottles, the little car has a fair amount of driving time for what it is, though. Also, it's just cool to see it actually working. The Lego truck has a little engine running on compressed air, carrying around its fuel with it. The only batteries involved are powering the various servos to enable remote control. We're all so used to seeing these things be powered by electricity, I guess seeing one powered by an energy source as unusual as compressed air is novel. As usual, I just want to see *more* after this. *Got a tip? Email us at tips@thedrive.com* ## Author Peter Holderith is a former staff writer for The Drive. He enjoys covering the regular news cycle, writing reviews, and hunting down long features on obscure pieces of automotive history. ### Author social links [LinkedIn]() [Twitter]()