Rotaries are a funny case. Look good on paper. Thermal efficiency issues. Smog. Seals. Noise control difficulties. Weird patches like bridge ports.
For modern passenger cars, it's kind of like overcoming the difficulties of two-stroke.
In anti-defense of 4-stroke ICE, it seems to me like we are hitting peak wacky complexity of those. Variable timing cams, turn off the cylinders, direct port injection, turbos, variable intake, complicated ECU. It's a far cry from a flathead 6 or VW flat 4.
Thank God electric cars are becoming more available, although I fear increasingly complex cooling and battery management and the 1000 things a software guy is going to add to them.
> Thank God electric cars are becoming more available, although I fear increasingly complex cooling and battery management and the 1000 things a software guy is going to add to them.
I'm hoping lithium iron phosphate starts to be used more in midrange vehicles; partly because they can be scaled up while sidestepping the potential resource bottlenecks around cobalt and nickel, and partly because they're very durable and cooling isn't usually much of an issue. Though heating might be an issue in the winter time (most LFP cells don't like being charged when temperatures are below freezing; heating might be necessary in winter).
Like those distorted maps of the united states weighted by population[1], your post should be read with "environmental compliance" as the center of mass. Yet you shrug it off like a footnote. Nobody, except perhaps ship designers, cares who has the biggest piston engines.
And what has happened since then? Google is showing me several engines with breakthrough efficiency in the last 10 years.
When I was a kid in the 90s, SUVs commonly got 12 MPG. The new models are 25 sometimes 30 MPG. Emissions have gotten considerably better in the last 30 years.
I’m looking and can’t find any info to back up the claim that this 1920s engine was more efficient than engines designed in the 80s and 90s. I am curious about it, not just is it true, but specifically what kind of efficiency you mean and what design features made it efficient. Do you have any sources or reading? Wikipedia talks about how the arrangement of the valves increased the efficiency, but only says this made it approach four stroke efficiency (at the time), not that it exceeded other designs. The 204 was a two stroke, and it seems to be common knowledge that even today, four strokes are more efficient. https://en.wikipedia.org/wiki/Junkers_Jumo_204
For modern passenger cars, it's kind of like overcoming the difficulties of two-stroke.
In anti-defense of 4-stroke ICE, it seems to me like we are hitting peak wacky complexity of those. Variable timing cams, turn off the cylinders, direct port injection, turbos, variable intake, complicated ECU. It's a far cry from a flathead 6 or VW flat 4.
Thank God electric cars are becoming more available, although I fear increasingly complex cooling and battery management and the 1000 things a software guy is going to add to them.