Karacticus GRM+ Memberand Dork
1/8/22 10:26 a.m.

My Dad sent me this article this morning about the rotary powered tractor he worked on during his career at John Deere. 

Javelin GRM+ Memberand MegaDork
1/8/22 11:04 a.m.

That is WILD. An 11.6L 2-rotor?!? 

j_tso HalfDork
1/8/22 11:29 a.m.

Good read.

It said the engine could also take diesel with its spark ignition. The only other diesel Wankel I've read about is Rolls Royce's that used a big rotor to compress it into a smaller rotor chamber.

BoxheadTim GRM+ Memberand MegaDork
1/8/22 11:34 a.m.

That thing must've had all the braps.

bgkast GRM+ Memberand PowerDork
1/8/22 11:41 a.m.

Thanks for the read. I had no idea that John Deere worked on developing rotary engines.

Karacticus GRM+ Memberand Dork
1/8/22 12:09 p.m.

Dad told me a bit more about the tractor this morning while he Skyped me.  In the tractor installation, the cooling system had to do some serious heavy lifting to get the heat out that was concentrated by the large amount of power produced in a small volume.  There was also a third party involved in a step down gear box to get the shaft speeds down to something they could deal with.  One of the basic physical items though was that the engine was relatively light weight, which is a disadvantage in a tractor.

I remember going to a technical presentation during that time period, and the target military application was amphibious assault vehicles for the Marines.  Light weight was an advantage there.  While a turbine engine (like on the M1 Abrams) was even better on weight, apparently in those vehicles, intake air is pulled from the crew compartment when waves wash over the intake, and the rotary could work with that volume of air, but there was no way a turbine could.

karplus2 GRM+ Memberand Reader
1/8/22 7:54 p.m.

Cool! We have a 2950 at work and it's my favorite tractor we have (all the other ones are 2013 and newer). Would have been interesting to run one with a wankel

That is super cool. I couldn't imagine starting that on a cold Midwest day. 

AClockworkGarage Dork
1/8/22 11:51 p.m.

Wow a tractor without torque. That'll come in handy.

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
1/9/22 12:37 a.m.

In reply to AClockworkGarage :

It's all about gearing :)

dean1484 GRM+ Memberand MegaDork
1/9/22 12:47 a.m.
Keith Tanner said:

In reply to AClockworkGarage :

It's all about gearing :)

This!!!  I bet that thing is a beast. 

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
1/9/22 8:04 a.m.
j_tso said:

Good read.

It said the engine could also take diesel with its spark ignition. The only other diesel Wankel I've read about is Rolls Royce's that used a big rotor to compress it into a smaller rotor chamber.

Mazda rotaries will run on Diesel if you warm them up first.  Allegedly, have not tried.


In the IMSA GTU days, Mazda was running a mix of race gas and kerosene to get 80 octane fuel with good combustibility.


The high mixture motion in Wankels seems to work well with low volatility fuels. Here's a pull-started engine developed for UAVs that runs on wide-cut military fuel.


pres589 (djronnebaum)
pres589 (djronnebaum) UltimaDork
6/7/22 9:58 a.m.

There's more to this story.  From the Wikipedia entry on Lycoming Engine Company;

"Another attempt to rescue Williamsport was made in introducing the "radical" SCORE engine, a Wankel engine originally developed through a joint venture between Curtiss-Wright and John Deere. Curtiss-Wright lost interest in the design just as it was maturing and sold its interests in the project to Deere, which brought in Lycoming to sell the developed engine into the aviation markets. It was guaranteed a startup run by Cessna, also owned by Textron. Just as production was ready to start, Cessna announced it was halting its small-aircraft business for an indefinite period, and SCORE was cancelled. The remains of the Deere licenses were later purchased by Rotary Power International, which briefly produced a 340 hp (254 kW) version."

Cessna shelving their piston aircraft in the mid-80's helped put a bullet in this project.  They jumped out due to liability / lawsuit issues and never touched the rotary again.  I think this is also what seriously wounded the Porsche aircraft engine effort of the 80's as Cessna dropped out of that as well for the same reasons and never sold any Porsche-powered aircraft.

A Wankel-powered tractor, while an interesting idea, doesn't really make sense to me.  A Wankel-powered Cessna 210, aircooled, does have a certain ring to it.

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