If you like video content that comes with the words Wankel, rotor, and rotary, Rob Dahm is probably one of the YouTubers you should follow. The man just loves his rotary, to the point that he's built a 4-rotor Wankel engine before and shoehorned it into, well, you've guessed it, a Mazda RX-7.
While the 4-rotor AWD, Jeep Grand Cherokee Trackhawk-beating RX-7 build was already crazy, to begin with, Dahm has just received something even crazier. We're talking about a 12-rotor Wankel engine, given to Dahm by a man named Tyson Garvin.
The engine displaces 15.7 liters but is enclosed in a big block the size of a Chevy V8. It's relatively compact in terms of actual size, and that's thanks to the power plant's Y configuration consisting of three, four-rotor banks.
What's even more bonkers is that Garvin built this engine at home. As someone in the video's comments section has perfectly put it, Garvin is the type of person who answers "Why not?" when someone asks "Why?"
Of note, Garvin's 12-rotor engine is probably the most number of rotors we've seen in a rotary engine. Dahm has shown a 6-rotor example at the start of the video, while running examples of the 4-rotor mill was the famous Mazda 787B that won the 24 Hours of Le Mans in 1991.
A bit of history about this engine: Garvin is really into speedboats. According to him, the idea of making this monster of a powerplant was born when he got tired of big block Chevy V8s that "break for the fun of it."
Although the teardown video above doesn't really show the 12-rotor engine being started or even fitted into a car (that's for another episode), Garvin said that his creation can rev up to 10,000 rpm and can produce up to 800 pound-feet of torque at 2,000 rpm. Previous reports show that it can produce up to 1,400 horsepower but can obviously do more with race fuel and turbocharging involved.
If you're curious how this 12-rotor Wankel sounds, here's a video from nine years ago while it was being tested on the dyno: