You Wouldn’t Download A Combustion Engine

Although 3D printing it a great tool for making all sorts of things, the nature of the plastics used in most desktop FDM printers means it isn’t the first tool most would think of to build an internal combustion engine. [Alexander] is evidently not most people, as he’s on his third generation 3D printed engine.

There are 3D printed pumps to distribute coolant water and oil, plus some clever engineering in the head to make sure they don’t mix — a problem with a previous iteration. As you probably guessed, the engine isn’t fully printed. Assembling it requires add-on hardware for things like bearings, belts, and filters.

But it’s still impressive just how much of this beast is actually made of plastic. Not even fancy engineering plastic, either — there are a few CF-Nylon parts, but most of it is apparently good old ASA and ABS.

If you’re looking for “cheats”, the plastic engine block does get a stainless steel sleeve, and the head is CNC’d aluminum, but we hesitate to call anything that gets a homemade engine running a “cheat”. It’s hard enough using all the ‘right’ materials. Just like another 3D printed engine we featured, the carb is also an off-the-shelf component.

Still, it’s the dancing bear all over again: it’s not how well it runs that impresses, but the fact that it runs at all. We’ve also seen hackers use 3D printing to make steam engines, hot-air Stirling engines, and electric motors— all with varying amounts of non-printed parts.