Alright, folks, gather ’round. Today, I’m gonna tell you about the time I tried to build a radial engine motorbike. Yeah, you heard that right – a radial engine, like those old airplane engines. It sounded cool in my head, I gotta admit.

So, first things first, I started digging around for info. Turns out, radial engines were a thing in airplanes way back when. And they made their way into motorcycles at some point. I found some posts online that mentioned the radial engine. One mentioned how they converted from the plane to motorcycles and the BMW motorcycle engine. I scratched my head a bit but kept going. I thought this would be a piece of cake, you know? Just slap an old airplane engine onto a bike frame and call it a day. Boy, was I wrong.
I managed to get my hands on a beat-up radial engine. I think it was from some old crop duster or something. This thing was massive, by the way, way bigger than any regular motorcycle engine. I spent days just cleaning it up, getting rid of all the gunk and grime. My hands were black for a week, I swear.
The Build
Next up, the frame. I figured I’d need something sturdy, so I went with a custom-built frame. Had to learn a bit of welding for that one. Let me tell you, welding is no joke. It’s hot, it’s messy, and it’s a lot harder than it looks. But after a few, uh, let’s call them “practice runs,” I managed to put together something that looked vaguely like a motorcycle frame.
Then came the hard part – fitting the engine to the frame. This is where things got interesting. I had to fabricate all sorts of mounts and brackets. My workshop looked like a mad scientist’s lab, with metal scraps and tools everywhere. There were moments when I thought, “What am I even doing?” But I kept at it.
- Engine Cleaning: This took forever. Grease, grime, you name it.
- Frame Welding: Learned a new skill, burned myself a few times.
- Engine Mounting: Custom brackets, lots of trial and error.
Somehow, after weeks of tinkering, I managed to get the engine mounted. It wasn’t pretty, but it was solid. Hooking up the transmission was another nightmare. I had to rig up a custom drive shaft, which involved a lot of guesswork and even more swearing. But eventually, I got it all connected.

Did It Work?
Finally, the moment of truth. I added some fuel, said a little prayer, and hit the starter. The engine sputtered, coughed, and then… roared to life. It was loud, it was shaky, and it was probably the most terrifying thing I’ve ever built. I took it for a spin around the block, and let me tell you, it was a wild ride. The whole thing vibrated like crazy, and it felt like it was going to shake itself apart.
So, did I succeed in building a radial engine motorbike? Technically, yeah. Was it practical? Absolutely not. It was a fun project, though, and I learned a ton along the way. Would I do it again? Probably not. But hey, it made for a great story, right?