5 ms·

I'm surprised the air intake isn't more aerodynamic, more like a fan blade to compress the air into the engine? Could this engine be fitted inside the rear whe

I'm surprised the air intake isn't more aerodynamic, more like a fan blade to compress the air into the engine? Could this engine be fitted inside the rear wheel to save space and weight as well?

bmelton 4y ago
That's a really good idea. Mazda is doing something that I think is fairly novel, which is almost exactly what you've described. They've scaled down the rotary engine from their RX cars to a single-rotor and put it into their new EV (almost tucked into the front wheel well,) and letting it act as a 70ish horsepower generator for the otherwise battery-powered car to extend range.
- tromp 4y ago
  Presumably this new model: https://www.greencarreports.com/news/1138444_mazda-mx-30-r-ev-is-a-plug-in-puzzle-americans-might-not-get https://www.greencarreports.com/news/1138444_mazda-mx-30-r-e...
- digdugdirk 4y ago
  Mazda really seems like the only company innovating in the ICE space (this, wankel rotary engines, skyactive engines) and their cars look damn good these days too. On top of that, they make fun cars. With buttons and knobs on the dash! I'm glad they're still around doing their thing.
  - CocaKoala 4y ago
    Mazda's also one of the few carmakers that's independent, as opposed to being part of a much larger conglomeration!
    - KRAKRISMOTT 4y ago
      No. Japanese conglomerates are not structured the same way as those in the west. Right now Mazda is semi dependent on Toyota, similar to Subaru.
  - bmelton 4y ago
    Agreed, but there's also Koenigsegg, which has managed to eliminate the need for cams, and complete heads from ICEs, replacing them with their 'freevalve' tech (which basically replaces the timing chain with computers so that instead of having one or two modes that a camshaft can opt into, you can precisely dial in bespoke timings for every RPM, or every RPM and speed, or ever RPM / speed / gear combination. They've also practically reinvented the transmission to invent a new transmission that eliminates moving gearsets and gives you a dual-clutchish transmission with a 6 speed manual AND a 9 speed automatic in the same device. IIRC, the Freevalve tech is like a 30% efficiency hack for any ICE you put it on, and it's a part of how Koenigsegg are managing to squeeze 600 brake horsepower out of just a 2L, 3-cylinder engine. Wesley Kagan reimplemented their freevalve technology on his Mazda Miata, and it's probably the coolest hobby automotive project I've seen in years. https://www.youtube.com/watch?v=E9KJ_f7REGw https://www.youtube.com/watch?v=E9KJ_f7REGw Here's a really cool explainer on the transmission - https://www.youtube.com/watch?v=Hvb6J96KiSM https://www.youtube.com/watch?v=Hvb6J96KiSM
    - aidenn0 4y ago
      People have made test engines with camless electrically actuated valves for a long time; it's just been too expensive to put in production cars...
      - bmelton 4y ago
        Considering the MSRP on your median Koenigsegg, it may still not be
    - digdugdirk 4y ago
      Absolutely love Koenigsegg, and their new engines are probably the current state of the art in (small scale) production ICE engines. I just feel like Mazda doesn’t get enough credit for the innovation they manage to accomplish at a truly mass produced scale. It's almost like they're too "normal" to get the attention they deserve.
      - bmelton 4y ago
  - slaw 4y ago
    Nissan released cars with variable compression engine.
  - coryrc 4y ago
    Wankel is noticeably worse in about every metric, especially pollution and lifetime, so I wouldn't be too excited about it.
    - digdugdirk 4y ago
      Agreed. I feel the same way about every programming language beyond assembly. I mean, what's the point of trying something new and different if it isn't immediately better than the competition in every possible metric?
      - coryrc 4y ago
        It's been 100 years.
- detourdog 4y ago
  This was done by BMW for the i3 with REX (range extender) equipped models. To be classified as an EV the gas tank range can’t be greater than battery range. This led to a 2ish gallon tank.
- jdmichal 4y ago
  I always wondered why "electric with an onboard generator" didn't take off as a subset of available vehicles. AFAIK, hybrids all work with complex gear boxes to allow the engine to directly power the wheels, while also charging the batteries. I suspect the answer is because it's more efficient from a MPG perspective to allow the engine to directly power the wheels, at the cost of the extra complexity of gearing. Converting motion to electricity back to motion is lossy, and even more so if you insert battery storage as an additional step.
hoosieree 4y ago
Actually mounting an engine inside a wheel increases "unsprung weight" which is bad for handling. But putting such small engines near the wheels (but still on the body so the suspension can do its job) that could indeed improve cargo space. Pushing the engine weight outward toward the wheels would also make the vehicle harder to rotate, which is bad for track cars and go carts, but good for passenger and freight vehicles.
AnotherGoodName 4y ago
You want the unsprung mass to be as low as possible. As in you want the wheels to be much lighter than the rest of the car for a smooth ride. The wheels should bounce around but the rest shouldn't. Newtons law and all. Putting engines in wheels causes a very rough ride. Even if the engine is light you're still likely creating an order of magnitude more unsprung mass. That's an order of magnitude rougher ride.

I'm surprised the air intake isn't more aerodynamic, more like a fan blade to compress the air into the engine? Could this engine be fitted inside the rear wheel to save space and weight as well?

bmelton 4y ago

That's a really good idea. Mazda is doing something that I think is fairly novel, which is almost exactly what you've described. They've scaled down the rotary engine from their RX cars to a single-rotor and put it into their new EV (almost tucked into the front wheel well,) and letting it act as a 70ish horsepower generator for the otherwise battery-powered car to extend range.

tromp 4y ago
Presumably this new model: https://www.greencarreports.com/news/1138444_mazda-mx-30-r-ev-is-a-plug-in-puzzle-americans-might-not-get https://www.greencarreports.com/news/1138444_mazda-mx-30-r-e...
digdugdirk 4y ago
Mazda really seems like the only company innovating in the ICE space (this, wankel rotary engines, skyactive engines) and their cars look damn good these days too. On top of that, they make fun cars. With buttons and knobs on the dash! I'm glad they're still around doing their thing.
- CocaKoala 4y ago
  Mazda's also one of the few carmakers that's independent, as opposed to being part of a much larger conglomeration!
  - KRAKRISMOTT 4y ago
    No. Japanese conglomerates are not structured the same way as those in the west. Right now Mazda is semi dependent on Toyota, similar to Subaru.
- bmelton 4y ago
  Agreed, but there's also Koenigsegg, which has managed to eliminate the need for cams, and complete heads from ICEs, replacing them with their 'freevalve' tech (which basically replaces the timing chain with computers so that instead of having one or two modes that a camshaft can opt into, you can precisely dial in bespoke timings for every RPM, or every RPM and speed, or ever RPM / speed / gear combination. They've also practically reinvented the transmission to invent a new transmission that eliminates moving gearsets and gives you a dual-clutchish transmission with a 6 speed manual AND a 9 speed automatic in the same device. IIRC, the Freevalve tech is like a 30% efficiency hack for any ICE you put it on, and it's a part of how Koenigsegg are managing to squeeze 600 brake horsepower out of just a 2L, 3-cylinder engine. Wesley Kagan reimplemented their freevalve technology on his Mazda Miata, and it's probably the coolest hobby automotive project I've seen in years. https://www.youtube.com/watch?v=E9KJ_f7REGw https://www.youtube.com/watch?v=E9KJ_f7REGw Here's a really cool explainer on the transmission - https://www.youtube.com/watch?v=Hvb6J96KiSM https://www.youtube.com/watch?v=Hvb6J96KiSM
  - aidenn0 4y ago
    People have made test engines with camless electrically actuated valves for a long time; it's just been too expensive to put in production cars...
    - bmelton 4y ago
      Considering the MSRP on your median Koenigsegg, it may still not be
  - digdugdirk 4y ago
    Absolutely love Koenigsegg, and their new engines are probably the current state of the art in (small scale) production ICE engines. I just feel like Mazda doesn’t get enough credit for the innovation they manage to accomplish at a truly mass produced scale. It's almost like they're too "normal" to get the attention they deserve.
    - bmelton 4y ago
- slaw 4y ago
  Nissan released cars with variable compression engine.
- coryrc 4y ago
  Wankel is noticeably worse in about every metric, especially pollution and lifetime, so I wouldn't be too excited about it.
  - digdugdirk 4y ago
    Agreed. I feel the same way about every programming language beyond assembly. I mean, what's the point of trying something new and different if it isn't immediately better than the competition in every possible metric?
    - coryrc 4y ago
      It's been 100 years.
detourdog 4y ago
This was done by BMW for the i3 with REX (range extender) equipped models. To be classified as an EV the gas tank range can’t be greater than battery range. This led to a 2ish gallon tank.
jdmichal 4y ago
I always wondered why "electric with an onboard generator" didn't take off as a subset of available vehicles. AFAIK, hybrids all work with complex gear boxes to allow the engine to directly power the wheels, while also charging the batteries. I suspect the answer is because it's more efficient from a MPG perspective to allow the engine to directly power the wheels, at the cost of the extra complexity of gearing. Converting motion to electricity back to motion is lossy, and even more so if you insert battery storage as an additional step.

hoosieree 4y ago

Actually mounting an engine inside a wheel increases "unsprung weight" which is bad for handling. But putting such small engines near the wheels (but still on the body so the suspension can do its job) that could indeed improve cargo space. Pushing the engine weight outward toward the wheels would also make the vehicle harder to rotate, which is bad for track cars and go carts, but good for passenger and freight vehicles.

AnotherGoodName 4y ago

You want the unsprung mass to be as low as possible. As in you want the wheels to be much lighter than the rest of the car for a smooth ride. The wheels should bounce around but the rest shouldn't. Newtons law and all. Putting engines in wheels causes a very rough ride. Even if the engine is light you're still likely creating an order of magnitude more unsprung mass. That's an order of magnitude rougher ride.