Rotary-Swapped Willys Jeep Does Its Own Kind of 700 RPM Idling “Burnout”

Why? This is the question Jeep folks, rotary fans and, frankly, a lot of other car nuts will throw at Seth Hensler (aka Red Eye Cage Garage on social media). And that’s because the man has given a Jeep Willys a rotary swap.

We’re used to Wankels being thrown in all sorts of machines these days, from a Mazda MX-5 Miata RF to a Ferrari 456. Given how lawmakers around the world are determined to retire internal combustion engines (it seems synthetic fuel will buy time, but at what cost?), you can always view this as a sign of protest, since rotaries aren’t exactly friendly to the planet. Me? Like so many Wankel fans out there, I simply adore the linear, high-revving nature of these engines, and, obviously, their shrieking soundtrack.

However, every single rotary build we’ve covered to date was all about beastly tarmac driving—cue to the thoughts about mixing the engine’s brap-brap song with the sounds of smoking tires. Not this one, though, as the machine is meant to keep its off-roading roots. Heck, it may even build on them. But what is this vehicle, exactly?

The condensed story of the Willys Jeep and where this unit stands

Back in 1940, Willys-Overland and then Ford got contracts to build “jeeps” for WWII. The former started production of the Willys MB (aka Jeep, from General Purpose Vehicle, or GP) in 1941. As for Ford, whose vehicles were essentially clones with small differences (the parts were all interchangeable), its production line started rolling in January 1942.

Once the conflict was over, Willys converted the vehicle into a civilian Jeep (CJ), with this entering the market as the CJ-2A in 1945. Four years later, it was replaced by the CJ-3A, which is the very chassis on our screens. However, this wears a 1945 Ford GPW body. In case you’re wondering, the name stands for G: government contract, P: 80-inch wheelbase, and W: Willys design.

The donor car for the 13B twin-rotor naturally aspirated engine Seth used here was a 1991 FC (second-gen) Mazda RX-7. This also gave away other parts, from the five-speed manual to the throttle pedal.

According to its builder, this is the world’s first four-wheel drive, 13B-swapped Ford GPW. And speaking of traction, the project features a 122:1 final drive, a Dana 44 5.38 rear end with a Samurai transfer case packing 6.5:1 gearing.

Yes, rotaries still have a lot to learn from piston engine in terms of torque, an asset that’s essential for off-roading. Nevertheless, the low gearing mentioned above and the lightweight nature of this Jeep, plus the almost tripled power, meaning there should be no issue out there on the trails.

For the record, the vehicle has lost 270 lbs thanks to the new engine, gearbox, and transfer case—rotaries are light and compact and while that may not matter for newer, beefier Jeeps, it does here. Thus, the Wankel Willys now tips the scales at just over 2,000 lbs. And yes, that includes the shovel and the axe on the driver’s side.

Rotary-swapped Ford GPW vs. VW TDI-powered Willys CJ-3A

In a crawling test, which awaits you in the first video below, Seth pits the 13B Jeep against a 1949 Willys CJ sporting a Volkswagen 2.0 TDI, even though he doesn’t offer the exact specs of the diesel, This proves the low gearing of the rotary works wonders—the expectation here is that it will compensate for the Wankel’s lack of torque, despite the engine’s 700 rpm idle being a tad much for an ideal off-road build. Of course, it also shows how much the man loves building these old Jeeps.

And, once we checked out the second vid below, a random drive on the road in this canvas-topped contraption, I became captivated by the quirkiness of the machine. I have to admit, the steering wheel knob drifting-with the rotary soundtrack-at the end of the clip is something I never expected to see outside the world of ridiculously eccentric racing games.

The third clip? This shows the “burnout” mentioned in the title, which would’ve probably set a world record (i.e., slowest) if it had been possible on tarmac.

The builder has recently fitted a resonator to address some of the 13B’s raspy exhaust sound. And it shouldn’t be long before this thing hits some properly rugged terrain, if it survives the scrutiny of the internet, of course.



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