A retro-style technical schematic of a Tri-Dyne rotary engine — the kind of diagram that made 12‑year‑old me fall in love with impossible machines.
Some engines are weird because they were built.
The Tri‑Dyne rotary is weird because it never was — and yet it still managed to lodge itself permanently in my brain after I saw a diagram of it in an old Encyclopaedia Britannica. (That article had an excellent diagram, but you can see the basic idea from the cover of the July, 1969 Popular Science magazine — link courtesy of books.google.com — and that cover was the inspiration of the Gemini AI Nano-Banana generated image above — very similar to the diagram in the encyclopedia.)
I remember staring at that diagram way longer than any normal child should stare at a hypothetical combustion chamber; in fact, I once used it in a project in high school for "what I want to be when I grow up," or something like that (the "what" was "automotive engineer" — I did work in the reactor department, mechanical division, onboard a Nimitz-class US Navy Nuclear Aircraft Carrier, but then I switched back to my computer days, and I've been doing that ever since).
The Tri‑Dyne was one of those “future of engines” concepts that lived entirely in beautifully rendered cutaway drawings. It promised all the elegance of a rotary without the Wankel’s triangle‑shaped chaos:
- three oscillating vanes
- three combustion chambers
- three power pulses per revolution
- and theoretically better sealing, efficiency, and sanity
It looked like someone took the Wankel, removed the Dorito, and replaced it with a mechanical flower that opened and closed in perfect synchronization.
It was mesmerizing.
It was elegant.
It was also, as far as I can tell, never actually built — which is probably why the diagrams looked so clean. Real engines leak. Real engines get hot. Real engines warp, seize, and fling metal shrapnel into the nearest wall. The Tri‑Dyne lived in a world where none of that existed. (Actually, to be fair, some of them only threaten to do that — usually the ones that are in vehicles I own — but the Tri‑Dyne never even got the chance; maybe we should rename it "Try-Dyne" since it never actually "did".)
But the idea?
The idea was intoxicating.
It was the kind of engine that made 12‑year‑old me think, “I’m going to build one of these someday,” and adult me think, “Ah. That’s why nobody built one of these.” (Actually, I'd still like to take a stab at building that thing someday... maybe I can get a 3D printer and build a prototype sometime.)
Still, I love it.
It’s the perfect example of the rotary dream: the belief that if we just rearrange geometry cleverly enough, we can escape pistons forever.
Spoiler: we cannot.
But I respect the optimism.