Return of Rotary Engine Confirmed by Mazda

[serialk11r]

https://www.motor1.com/news/447897/m...n=RSS-all-news

If they have managed to make this all aluminum, then I would love to rip a range extender out and convert it for sports car use

As a range extender, it needs to be at least somewhat efficient, because it's silly to save weight on the engine if you end up needing a lot of extra fuel. The obvious trade to make is increase rotor surface temperature to reduce unburned fuel at the cost of low end torque. It also needs to be reliable, so hopefully they've decided to incorporate ceramic coatings and seals as standard.

[weederr33]

Why the hell would Mazda stick a rotary motor in a Crossover?

[serialk11r]

Originally Posted by weederr33

Why the hell would Mazda stick a rotary motor in a Crossover?

I think this is one of those "because we can" things. A 1 or 2 cylinder piston engine that produces 50hp or something is really not very heavy or big, though it would have a lot more NVH. I can't imagine it would be hard to tuck a 2 cylinder engine under the hood of a crossover.

Nevermind the CX-30, the thing to be excited for is a custom crankshaft and lightweight rotors to make a 2-rotor 10000rpm beast.

[Irace86.2.0]

Originally Posted by weederr33

Why the hell would Mazda stick a rotary motor in a Crossover?

A range extender is used to power the battery for more range on an EV. The idea is the car can run on the electric motor and battery alone for most daily activities, but the small engine can recharge the battery when necessary for longer trips or provide some reduction of range anxiety. This is much different than a hybrid where the electric motor and ICE are both connected to the axles, and where the ICE needs to be larger to propel the car as a primary mover, and where the electric motor and battery are smaller because they are used in low load situations to increase fuel economy.

A small rotary engine could act as a more efficient, lighter, smoother and more compact range extender than a typical one or two piston “motorcycle” engine.

https://www.caranddriver.com/reviews...r-test-review/

The BMW i3 with the range extender uses a...

We tested both i3s models, including the REx version—which means it had the additional range-extending 38-hp, 647-cc two-cylinder engine and dedicated generator tucked under the rear cargo floor—as well as the standard car powered solely by electrons. While both feature the same 33.2-kWh lithium-ion battery pack, foregoing the range-extending option saves 274 pounds at the curb.

In REx form, opting for the i3s doesn't have any effect on this green machine's bragging rights. The EPA rates it with a driving range of 97 miles on the battery pack, plus another 83 miles with a fill of what amounts to a 2.3-gallon jerry can. The two-cylinder engine fires up and drinks from that meager supply only when the battery is nearly depleted. There's no mechanical connection between the engine and the drive wheels, so it only plays the role of an onboard generator. The i3s EV, in contrast, is rated at 107 miles of driving range and a combined 112 MPGe versus the standard i3 EV's 112-mile and 118-MPGe figures.

[Atropine]

Everything from the website "motor1" is unadulterated bullshit.

Now you know.

[Dadhawk]

Originally Posted by Irace86.2.0

A range extender is used to power the battery for more range on an EV.

Exactly.

This isn't new tech. It is basically how the Chevy Volt works, and is how diesel locomotives have worked for years, although without the battery I believe in case of the locomotive.

I would love to have a car that was pure generator driven, no massive battery pack. OK, it's not "green" but it would have the performance of an electric without the compromises.

[dragoontwo]

Originally Posted by Dadhawk

Exactly.

This isn't new tech. It is basically how the Chevy Volt works, and is how diesel locomotives have worked for years, although without the battery I believe in case of the locomotive.

I would love to have a car that was pure generator driven, no massive battery pack. OK, it's not "green" but it would have the performance of an electric without the compromises.

I like this idea, too. it would be interesting to see this kind of tech advanced and see what kind of motor comes out on top as the best generator(or alternator). Diesel, gas, rotary, LP?

[Dadhawk]

Originally Posted by dragoontwo

I like this idea, too. it would be interesting to see this kind of tech advanced and see what kind of motor comes out on top as the best generator(or alternator). Diesel, gas, rotary, LP?

Freedom Motors has been working on a rotary for this purpose, amongst others, for years and has shown a high output rotary working in various applications including hybrids. They claim 1.5 HP per engine lb in their "high performance model".

Of course, the problem is this is a Paul Moller company. Moller was the inventor of the Super Trapp muffler, sold that then spent that money (and a lot of investor money) over the last 30 years trying to build a "flying car" that was going to ready "any day now". The rotary motor is an offshoot of the Moller airplane project. Basically, as far as I can tell he's a well intentioned snake oil salesman at this point.

I think this has much more potential than his aircraft and "flying saucer" business, although the plane concept is damn sexy.

[Irace86.2.0]

Originally Posted by Atropine

Everything from the website "motor1" is unadulterated bullshit.

Now you know.

Every news website is reporting the same thing. Just saying in case you are trying to suggest they are fabricating this story. Also, watch the video for yourself.

[Ohio Enthusiast]

Originally Posted by Dadhawk

I would love to have a car that was pure generator driven, no massive battery pack. OK, it's not "green" but it would have the performance of an electric without the compromises.

Coupled with a small battery to smooth out power demand, it would allow the ICE generator to be optimized to a very narrow RPM/load levels, making it more efficient and environmentally friendly. It would basically be a better hybrid. On the sliding scale between full ICE and full EV, typical hybrids are closer to the ICE side (with the ICE providing the bulk of the power) and plugin hybrids are about in the middle (with the ICE and the electric engine providing similar levels of power). This would be closer to the full EV, with the electric engine providing the power and the ICE just charging the small battery.

[serialk11r]

Originally Posted by Dadhawk

I would love to have a car that was pure generator driven, no massive battery pack. OK, it's not "green" but it would have the performance of an electric without the compromises.

That's called a series hybrid. Doesn't really work if you want performance because the generator has less power than a normal engine because it's supposed to represent the average load. You would need an intermittent power source (small battery or capacitor pack), and the car would only be barely faster on the track than something powered by the same engine.

I guess on the street you only need short bursts of acceleration which is maybe what you were getting at. In that case yes, you could end up with a lightweight car using a tiny generator, though it would struggle to climb a mountain since the battery would be quickly depleted. At the end of the day though, if you're hauling around say 100lbs of battery (with today's technology this actually isn't enough, you would only get around 200hp out of this), 100lbs of generator (this is being very generous, even a single rotor wankel generator is probably going to be more than this all in), 50lbs of gasoline, then another 200lbs of electric drivetrain, you could easily have a gasoline engine putting out similar power for the same mass.

A mild hybrid runs the engine less efficiently but has less drivetrain losses, and it can produce near peak power continuously. The gasoline engine's low end torque can be completely ignored, making it better at producing max power, and you get the benefit of hearing glorious engine revving noises.

I've posted about Freedom Motors a few times around here, their ideas are surprisingly simple, but the ceramic seals are probably the dealbreaker cost-wise. 1.5hp/lb is an underestimate because that's rated at only 4500rpm (the power should be climbing past 8000rpm). You'll notice that the "high power configuration" is more like 2.5hp/lb, and that's at 7500rpm. If Mazda is getting into this game though, then there's hope that they've made more affordable long-lasting apex seals and reduced oil consumption.

Wankels really are a great fit for racing because they're mechanically simple, compression ratio is geometrically limited (so it's naturally biased towards high-load efficiency) and high-rpm efficiency is good if you add more spark plugs (much easier than adding spark plugs to a piston engine or jet ignition or multi-point laser ignition).

[Dadhawk]

Originally Posted by Ohio Enthusiast

This would be closer to the full EV, with the electric engine providing the power and the ICE just charging the small battery.

That's pretty much what I was thinking as well. It would also allow for storage of energy created by the generator when peak load isn't needed.

[Dadhawk]

Originally Posted by serialk11r

That's called a series hybrid. Doesn't really work if you want performance because the generator has less power than a normal engine because it's supposed to represent the average load.

That all makes sense, and is why I don't design cars, but leave it to those that better understand it. I'm an idea guy, but they aren't all good.

[Tcoat]

Whooo Hoooo they are going to use a rotary powered generator.
Don't expect to see a whole line up of ICE powered rotary sports cars.
This is the beginning of the end of ICE powered cars not a new era of rotary RX models!