3 ms·

It's not just air, its usually compressed air above atmospheric sea level (bar+). This opposed-piston architecture appears more complicated. Adding an additiona

by semerda 12y ago

It's not just air, its usually compressed air above atmospheric sea level (bar+). This opposed-piston architecture appears more complicated. Adding an additional crankshaft isn't a small feat. Removing valves that rely on the rotation of a crankshaft is a small win. Add bar+ of pressure into a combustion motor like this and watch it pop. Too many moving pieces! But saying this, what is the drive to keep on overcomplicating things like traditional combustion motors? The Wankel engine was simple, small & powerful (when a turbo hanged off it). The industry killed it to replace it with a more complicated piston engine. And now this more complicated architecture proposal. I would love to see engineering innovation focusing on simplification like that which exists in electric motors. There is still so much more that can be done with magnets & coils.

Gravityloss 12y ago
Emission controls have become a lot stricter. In heavier engines, they are the major technology driver now. Wankels have a crescent shaped combustion space. That is bad for emissions as the far away thin corners dont burn so well.
- semerda 12y ago
  Yap I understand why Wankel didn't meet emission standards. But neither would have the standard piston architecture if it weren't for innovation i.e. extension of it's complexity. As a ex-fan of combustion motors for many years, and having built a race car, I no longer see investment in combustion motors as sound. Electric motors are far simpler and smaller and are starting to yield similar results to combustion motors. That's where innovation should be heading.
  - jrapdx3 12y ago
    As a past owner (many years ago) of a Wankel-engine powered car I was entertained at the mention of "Wankel". Emissions were the least of its problems, reliability being far less than desirable, as in barely able to keep going at all. Later on there were more reliable rotary engines, e.g., Mazda. If memory serves, there were emission problems and the engine was eventually discontinued for that reason. Rotaries were an interesting idea, hypothetically better, but implementation was obviously difficult and ultimately a failure. In today's world, we need to stop burning fossil fuels and electric-powered vehicles look promising. I'm looking forward to advances that will make electric cars practical. Of course, burning coal or natural methane to make electricity wouldn't be ideal, though possibly more efficient than the distributed combustion we now use.
  - Gravityloss 12y ago
    Audi was considering a Wankel range extender for plugin hybrids around 2010 but they later moved to conventional three cylinder engines. I don't know the specific reasons for that.
- auxym 12y ago
  I don't have a reference on hand, but everyone I've spoken to who has worked close to engines (in the automotive, recreative and commercial transport industries) has said to me that compliance to emissions is now the leading design consideration. So, not only heavier engines, unless by "lighter" engines you are only referring to lawnmowers and such.

by semerda 12y ago

Gravityloss 12y ago

Emission controls have become a lot stricter. In heavier engines, they are the major technology driver now. Wankels have a crescent shaped combustion space. That is bad for emissions as the far away thin corners dont burn so well.

semerda 12y ago
Yap I understand why Wankel didn't meet emission standards. But neither would have the standard piston architecture if it weren't for innovation i.e. extension of it's complexity. As a ex-fan of combustion motors for many years, and having built a race car, I no longer see investment in combustion motors as sound. Electric motors are far simpler and smaller and are starting to yield similar results to combustion motors. That's where innovation should be heading.
- jrapdx3 12y ago
  As a past owner (many years ago) of a Wankel-engine powered car I was entertained at the mention of "Wankel". Emissions were the least of its problems, reliability being far less than desirable, as in barely able to keep going at all. Later on there were more reliable rotary engines, e.g., Mazda. If memory serves, there were emission problems and the engine was eventually discontinued for that reason. Rotaries were an interesting idea, hypothetically better, but implementation was obviously difficult and ultimately a failure. In today's world, we need to stop burning fossil fuels and electric-powered vehicles look promising. I'm looking forward to advances that will make electric cars practical. Of course, burning coal or natural methane to make electricity wouldn't be ideal, though possibly more efficient than the distributed combustion we now use.
- Gravityloss 12y ago
  Audi was considering a Wankel range extender for plugin hybrids around 2010 but they later moved to conventional three cylinder engines. I don't know the specific reasons for that.
auxym 12y ago
I don't have a reference on hand, but everyone I've spoken to who has worked close to engines (in the automotive, recreative and commercial transport industries) has said to me that compliance to emissions is now the leading design consideration. So, not only heavier engines, unless by "lighter" engines you are only referring to lawnmowers and such.