Wankel intended his unit to be a true rotary [ engine revolves around grounded crankshaft] to utilize air-cooling, but referred to his production units as being a rotating piston design…
If there is any merit in the ‘Liquid Piston’ set-up, I `d wonder if Toyo Kogyo hasn’t checked it out…
Incidentally, Mazda pushed the technically improper ‘rotary’ nomenclature - as a way of avoiding paying royalties on the Wankel name…
Page 93, July 25th 1946 edition of Flight ; [available in on-line archive] ,
Has an interesting plan of a proposed 500+ mph Napier Sabre powered fighter using advanced ducting methods…
The citation of the Stirling engine was just a joke on my part,(and a rather obvious one I might add ) although they would be appreciative of the increase in power available in the lower temps at altitude, the Stirling of the 40’s would be more at home in a river barge. They were used in shipping for awhile, but the room required for them took space needed to revenue producing cargo. The pistons and displacers moved slowly enough for people to ride on while in operation.
As to the Wankle, even after the the problems of uneven wear on the inner surface of the rotor, and the apex seals were finally resolved, it still used too much fuel. Mazda would have been better off getting a license to use John Marshall’s Tri-Dyne rotary engine. Since the Tri-Dyne wasn’t around in the 40’s it wouldn’t be much help in War time aviation.
Mainly due to emissions in the U.S., but yes, fuel efficiency is a big problem despite the excellent power output to displacement ratio. The Wankel rotary also received a bad rap in the United States because the turbo-charged variant of the last gen of the RX-7 tended to destroy itself after about 60K. They pulled it out of North America yet solved the problem and continued to sell them in Japan for a while after. They had the RX-8 here, but the horsepower was dampened again by emissions whereas the car had about 20 more horsepower in Japan…
For some reason the automatic Rx8 was detuned too, - but I really liked that triple rotor howling sound made by the 20B Rolex championship sports-racing Rx8s…
They were fun to drive, I think Mazda was shying away from the super-car thing as the last of the RX-7’s were virtually on par with Corvettes and more expensive Euro performance vehicles. The RX-8 was marketed as a nice, fun car to drive with real world performance. But it wasn’t powerful enough for enthusiasts and the fuel economy was abysmal. Also, Mazda went to their MazdaSPEED entries for the turbocharged Mazda3 in the U.S. as their performance niche making the RX-8’s obsolete. And many people who would have bought an RX-8 simply opted for the Miata. I think they’re still working to comeback with a Rotary powered sports car in the future…
There were some Corvettes that had Wankel engines in them, though they never made it to a showroom. The XP-895,(1973) an outgrowth of the XP-882 program (a Corvette with a transverse V-8 Mid-Engine design) The 895 used a pair of joined 2 rotor engines from another Chevy product program. This was later changed to the XP-897GT which used a single 2 rotor engine, along with some other design changes. The entire program was tossed out as the fuel shortages of the early 70’s made it unlikely to be a sales success.
They’ve probably taken a look and left it at that for now. As with any prototype engine, there are enormous hurdles to be overcome before you can even think about commercialisation. Far better to have them continue to work on it, and license the design if it ends up working moderately well in order to refine it for mass production.
Personally I suspect Mazda will never use it for a road car (or if they do, it’ll be a niche model for remote areas) - given the trajectories of oil prices and battery performance, in 20 years or so I think cars will be overwhelmingly electric. It does have potential use in aviation though, where weight is critical.
Electrickery…nah…battery power is a dead-end,… heavy, limited range & long re-charge times…useless…
Unless maybe an electromotive type, with a high-efficiency liquid/gas fuelled ceramic 2-stroke turbo-diesel engine running at max torque - as generator to electric drive…
…& maybe with an electro-regenerative motor at each wheel, like Porsche drew up over a century ago…
Or a NASA surplus, deep-space probe, plutonium fuel-cell electro-drive…
Back to the Stirling engine we go, even Sears, and Roebuck sold them in the latter 1800, they did well for field engines on the farm, and in mining. Sears even sold a solar version having a cast iron collector at the top. modern incarnations of the Stirling might well do for a car. (as long as no one wants it to go very fast. )
Recharge time has been demonstrated in the lab to be a product of microstructure, not chemistry. They’ve demonstrated on a benchtop scale the technology to recharge a car with ~300 miles of range in under a minute, for a total system weight very comparable to current petrol-based systems. Given the throttling losses IC engines experience, once you get the charge speed and cost right (which is now a matter of engineering, not science), electric cars will always be cheaper to run.
I wish they were cheaper to buy, for my general inclement weather needs, a battery only car would do a good job. The price is much too high at present to make a purchase worthwhile. I appreciate the technology, and all of the present troubles one may avoid by driving an all electric, (and can only wonder at what future troubles they may present us) but its still too costly. I have hopes that the GM Highwire will someday be available at something approaching a realistic price, would have one in a heart beat, fuel cell clean, but no range limitation.
Prices are coming down pretty rapidly, the likes of the Nissan Leaf are still pretty expensive but that’s always the case for a first prototype. Give it another decade and they’ll be on a par with combustion engines.
The Leaf is available here in the mountains, I had given it a look over. Would be fun to have one someday.
Wonder what hill climbing power usage will do to battery endurance/car range?
I 've heard proposals that quick swap battery packs will become available, at gas stations, or maybe Hydrogen fuel cells…
How does running other power ancilliaries [ heating/aircon/lights/sound systems & etc] affect battery car range?
Maybe there is a Tesla wireless energy transfer system coming…kinda like a slot-car - but without the need for direct electrode [source-to-pickup] contact?
Like any other finite power source, the more you use, the faster it’s depleted. They don’t have a great deal of range to begin with, maybe 100 miles best conditions, start using hvac, wipers, lights, etc. and that would lessen the useful range considerably. The brakes should be regenerative, like dynamic brakes on a locomotive, and should recharge the battery pack as you go along. Just found a video about it, so if you like, have a look.
http://youtu.be/0_4fvEwXros
although when I think about it, one of these would be fun too… http://youtu.be/ZFcanpNarEg