New engine could save internal combustion from the scrap heap
motor1.com
motor1.com
I have a 1981 Diesel Chevette which can get 50 miles to the gallon when driven at a steady highway speed. If that forty year old fully iron engine can get 50 miles to the gallon in a car that's as aerodynamic as a brick, then why aren't new cars getting 80 miles to the gallon? Is our technology really that shitty? Or is it that the carmakers have marketed performance and "sportiness" to us over efficiency?
They certainly don't want to make engines that can last forty years and 750,000 miles, but that's another issue.
So the real question is this: if we can have 80, 100, 150, perhaps even 200 mile-per-gallon combustion engines, and if we can grow biodiesel from algae and even produce it using processes which pull CO2 from the air, then how much energy and carbon output could we save by not building limited life batteries and by not suffering the waste of electricity transmission and storage?
It's not all one thing or the other, and it never should be, but we've been milking the old internal combustion cash cow for so long we've virtually guaranteed her death, even though evolution of the internal combustion engine would be a net benefit.
I say it's time for a corporate revolution.
And yet, here we still are.
Old cars do well steady state, but are far less efficient in transient states; modern engines are far better at that.
Old cars have absolutely toxic emissions. I mean literal 100's of times worse than modern engines (especially diesels), which are already terrible.
Couple these two major factors and you'll see where most of the advances have gone. That said, I don't think you are completely incorrect either; incentives have to be put into the right places to drive these innovations forward.
If you want to see state of the art efficiency for fossil fuel engines look at trains. They are more heavily regulated for emissions than bunker fuel ships, and the amount of fuel per ton-mile used is tiny compared to a personal vehicle due to a few factors (load vs vehicle weight, efficiency of acceleration/deceleration, engines operating only at peak power/efficiency and the traction motors being electric, etc.).
On a side note, the lack of parts to keep an old car in compliance with emissions is driving me insane. My hobby car is a HUGELY popular car from 20-30 years ago and the supply of parts to keep it on the road is drying up already. Due to it's factory state of tune (naturally aspirated, ~100hp/liter) aftermarket discount parts are not suitable and fail quickly, sometimes damaging other parts. OEM parts are so rare now that they are getting painfully expensive to continue procuring them, and for emissions related systems the only quality parts left are the high end aftermarket (which aren't legal). It's becoming almost impossible to keep these vehicles legal, which I'm sure is intended. I'm at the point where I'll likely run the "illegal" (though perfectly identical if used properly) parts for 23 out of the 24 months it's on the road, and only use the almost impossible to obtain OEM parts for the 1 month needed to get it sorted for emissions testing.
Yes, even if they're physically indistinguishable. (And they would be physically distinguishable because 3d printed parts can be distinguished, even if they perform identically.)
It's a legal thing.
If we agreed (not suggesting this for obvious reasons) that everyone would just build ultra lightweight and fairly low power vehicles, I think 80 mpg is feasible, but probably a lot less safe.
A Beetle from the 50's might have 30-40 horsepower. You can pretty easily get cars with 10 times as much power now.
https://jalopnik.com/i-lived-with-a-japanese-kei-car-for-a-w...
A 2022 Corolla is ~3,000 pounds.
The Corolla has ~3x the horsepower.
Forty years is no problem already and a typical Honda/Toyota 4-cylinder engine is already a favorite to make 250K miles. Our CR-V just passed 225K miles and rust will kill that car long before mechanical problems do.
750K miles will cost you over $100K in direct operating costs (fuel and wear items). I don’t know that making an engine last 3x as many miles is that big a benefit to a new car buyer.
Modern cars are a marvel of cheapest manufacturing and materials. What would we accomplish if we optimized for corrosion resistance? It's not like we don't have the materials or processes. But they're nowhere as cheap as stamped sheet steel.
My first car was a 13 year old Toyota Tercel. It had literal 8"+ rust holes in every door, the frame had rust holes, and the fenders were falling apart from rust. My second car was a 10 year old Cutlass Supreme. It had a 6" rust hole one door, a rust hole in one fender, and plenty of other rust underneath. This does not happen anymore, except maybe trucks used for salt.
As for engines that last 40 years and 750,000. If you look after Diesel engines they can get to 500,000 or more. However people don't once the car gets over like 100,000 miles. Servicing costs typically more than the car is worth.
https://www.youtube.com/watch?v=fPF4fBGNK0U
You causing more pollution (particulate, NOx, etc) than a hundred luxury SUVs or more, is the difference.
Driving down the highway at 75mph able to hear the back seat passenger whisper versus having to talk loudly so the person in the front seat next to you can understand you.
A climate control system that keeps the car comfortable whether it is -20 degrees or 100 degrees.
Handling, brakes, and acceleration that is astronomically better than whatever your Chevette has.
There's no such thing as a "200mpg engine" - most modern car engines are very efficient, with the Prius's Atkinson cycle engine being the most efficient among worldwide-available, mass-production, affordable cars. It's a function of aerodynamics, parasitic electrical and mechanical losses, and weight.
> It's not all one thing or the other, and it never should be, but we've been milking the old internal combustion cash cow for so long we've virtually guaranteed her death, even though evolution of the internal combustion engine would be a net benefit.
Making an engine that would last 750,000 miles is certainly possible - just look at engines in big rigs - but people don't care about that in a personal vehicle, and the capex and opex for such an engine is incredible compared to the cost of making it significantly cheaper but slightly less reliable.
They want a low price tag and low maintenance during the period they own the car. That's why most engines have a 10k oil change interval (though part of that is due to much improved quality of oil, and better filters.)
Because those modern cars have airbags, and thick pillars, etc, etc, etc and it's for your own good, peasant.
(also emissions, but modern tech to control emissions makes that a wash in the fuel economy department because said tech enables the engine to operate more efficiently on a per fuel basis)
https://theicct.org/nox-and-co2-emissions-from-trucks-what-t...
My Prius can easily do 60 mpg when driven on a flat road at highway speeds, and while it’s no speed demon in the quarter mile, it’s at least safe to operate. Plus it has more cargo carrying capacity and its vastly more pleasant to drive than a chevette.
Even my cheap dad got rid of that car as soon as possible.
> if we can have 80, 100, 150, perhaps even 200 mile-per-gallon combustion engines
Well, we can't.
Internal combustion engines have steadily gotten better, not stagnated.
In the 1970s, I heard all about oil companies buying 200 mpg carburetors to keep them off the market. My dad laughed at that, saying the military would never let patent law keep them from making 200 mpg tanks and stuff. Gas is a gigantic logistical problem for a mechanized military.
I've seen plenty cars get 300,000 miles here in Texas without a spot of rust on them. Do you live in Michigan or something? The salty states have only known rust and salt lol
It takes a lot of work to keep an older car running. My truck is 35 years old, and the window rollup mechanism has disintegrated. The seals around the doors and windows have rotted away. Knobs are missing. The door latch bushings disintegrated and I can't find new ones. The trim, which was glued on at the factory, simply fell off. The paint is about as shiny as an asphalt shingle.
The engine runs fine, though :-)
https://www.cummins.com/news/releases/2021/07/30/us-army-awa...
Cummins and Achates Power was supposed to have delivered two working prototype engines to the US Army's TARDEC to be installed into a Bradley for evaluations in 2019. I'm assuming that they testing went well enough to prove that the engines are viable enough for further development.
Uncertain if the technology will ever meander it's way to regular car market, but interesting to see ICE development continue on.
I know nothing about that story, but the military is budgeted by Congress and commanded by the President, and thus subject to political influence. Plenty of the what the military does is inefficient economically and militarily.
Do you think any military is going to allow itself to be crippled by patents?
In WW1, the American aviation industry was crippled by patent lawsuits. The government put a stop to that nonsense and forced them to form a patent pool, so advanced military airplanes could be built.
Outside of that? Sure. Particularly if the crippling allows for an element of surprise and keeps that tech out of other peoples hands. Even without that though every country that isn’t spending the most it can on its military is choosing to ‘cripple’ it in favour of other things.
That might make sense in theory, but the history of war profiteering, etc. is otherwise. Militaries are 'crippled' by poor materials (though 'crippled' is an extreme case) - especially at the beginnings of wars.
For example, many think most US airplanes are ineffective against serious foes, including the A-10, F-35 (not my opinion, but many think it), and all the older planes (including the new-old planes they recently signed to buy). That also applies to aircraft carriers. However, there are many vested interests in those weapons programs and they resist tooth and nail. Change requires aligning people within the national security community, the easy part, and then Congress and the President. Uniformed and civilian officials in the Department of Defense can be just as political and corrupt; many of both sorts go through revolving doors to industry and have careers invested in one thing or another, or simply, like many incumbents in many fields (such as IT), bury their heads in sand about change.
> allow itself
They have limited power to make these decisions, at least in democracies.
http://www.douglas-self.com/MUSEUM/POWER/unusualICeng/unusua...
We'll have to see if this one does anything different.
Battery-electric vehicles have such a huge efficiency advantage that I don't think ICE vehicles will ever be remotely competitive if you had to synthesize the fuel directly using renewable energy. A more efficient ICE engine (if it can live up to that claim) would be better than using old less-efficient engines, but I think we're at the point where the best option is not to use engines at all unless it's absolutely necessary for that application.
In a similar vein, my 2007 diesel Toyota Yaris regularly passed 60MPG and occasionally reached 70MPG before it was written off in an incident about 3 years ago.
If so, then the fact that you can have two involute shaped mating surfaces as valves (almost no sliding, just a rolling contact), and a rotor that could be statically and dynamically balanced to almost zero vibration, would be amazing.
It seems like this thing could rev really high, since there's no herky-jerky motion.
At this point, most of the parts of an EV are quite mature, and the overall system is a lot more straightforward than a conventional ICE car. A rear motor (or pair) can drive the real wheels without a transaxle or multi-speed transmission. Traction control can be achieved by rapidly adjusting torque. Regenerative breaking massively increases brake lifetime and reduces particulate emissions. 4WD is relatively inexpensive and increases efficiency (because the front and rear motors can be optimized for different operating regimes, and one can be turned off whole cruising). An electric A/C compressor can operate at the optimal speed for the A/C without regard for driving conditions. A small battery pack that can produce plenty of power for bursts of acceleration under anything except racing conditions is essentially a commodity.
So I think a series electric car with a 150kW (not kWh, and only supplying 150kW in brief bursts) and a small, highly efficient 30-40kW gasoline engine would be fantastic. And that engine would not need to have low efficiency and high emissions while warming up at low speed — when it turns on, it could immediately run at its optimal operating point even if the car is stuck in traffic.
Heck, a manufacturer could sell the engine as an optional feature — many customers could simply skip the engine and drive the car as a short-range EV.
The Chevrolet Volt used a similar principle as well, as opposed to the Prius and its more complicated mechanical duel-drive train.
This is different from pure electric drivetrains like diesel-electric locomotives where the fuel is only used to generate electricity and all of the propulsion is by electric motors.
A 30kW generator will produce 30kWh in an hour, which is enough energy to drive 120 miles and well above any average travel speed required.
In ideal conditions a 20kW generator would be enough to drive with a completely depleted battery at highway speeds, and a 10kW generator would be enough to significantly extend your range.
Which might be necessary.. a 30kW generator running at fult tilt while sitting at a stop light might be a rather unusual experience. Also looking at commercial extended duty 30kW generators makes me wonder where you're going to put that on an already 4,000lb car.
This setup is already used in diesel-electric locomotives and submarines but hasn't really been applied to other transport systems for various reasons. It's something I've been working on as a side project although maybe it's time to launch it as a startup.
There was another that was also sort of like a Wankel. In it the triangular Wankel rotor is static, and the combustion chambers rotate around it. They have a working model with transparent parts so you can watch how it works.
Nothing in the Omega 1 presentation seemed to offer any clue how it works or why it is better.
These engines both seem like viable general-avition engines to replace Lycomings and Continentals, because electric is not really up to the job. FAA should take initiative to get these approved and deployed, because nobody can afford to do it privately.
Still, FAA probably should look into pre-approving such a configuration, too.
I.e., there is no constitutional restriction against Congress assigning such a task to some agency. NASA might be best organized, of federal apparatus, to do the work, maybe under a future "General Aviation Revitalization Initiative" authorization, maybe letting contracts for actual development.
The problem to be overcome is that nobody private seems to be rich enough to jump through all the regulatory hoops to get a modern engine approved to build modern small aircraft around, no matter how much better one could be.
I don't know why a Cessna-size turboprop mill never got to market. Is periodic maintenance and inspection of turbines prohibitively expensive?
For small aircraft turbines: Cessna makes the 208 Caravan. If the 208 is too big, Quest makes the Kodiak and Socata makes the TBM. If someone’s going to pay all the purchase and operating costs to run a PT6 turbine, they might as well drag around a medium-sized airframe.
Maintenance and inspection of turbines isn’t prohibitive. Initial purchase price and specific fuel consumption at low altitude is a far greater concern for private operations.
Pistons are way more popular simply because of economics. Virtually everything else about turbines is better. If I could afford a turbine, I’d switch to one immediately.
I interpret the facts on the ground to mean qualifying a new light-aircraft power plant is in practice prohibitively difficult and/or expensive, and needs assistance, maybe even statutory assistance.
Ferrari sells almost as many cars in a month as light aircraft are sold in a year. I’m not surprised that people aren’t lining up to compete for those scraps.
It is a safe bet that if small aircraft got as cheap and performant as is in easy reach of modern engineering and production capabilities, there would be a lot more of them bought and used. Halving cost ought to result in much more than twice the demand.
For comparison, we may look at solar panels. There have been no fundamental advances in a long time, but increasing volume triggered by heavy Chinese subsidies kicked the market into a different mode it is still far from settled into.
Probably there are lots who would rather general aviation not become a lot more accessible, but that is policy, not fundamental economics.
In many ways it’s like other expensive hobbies. Horses aren’t expensive because they’re rare or complex to make. Blue water sailing isn’t expensive due to lack of innovation in boats.
You could have said the same about computers just a few years ago. Now you carry a supercomputer in your pocket and complain how slow it is.
Nothing is more efficient under power; turbines are only inefficient at low power settings (descents, taxiing, etc.)
Idea is that if you can use a battery to boost output power for takeoff and climb out, for that few minutes, you can get along with a much smaller turbine just for cruising than you would need for a turboprop, so is cheaper. And, if the turbine drives a generator directly, it doesn't need the step-down gearing you would need to drive a prop, and you can run the turbine at a constant speed any time it runs at all, more efficiently for that and without gear-train loss. And, it can run on jet-A fuel, which is cheaper per kWh than Avgas.
I don't know where a turbine of the right size is in use, that could be re-purposed.
It seems to avoid the expensive fabrication a turbine needs for all those blades.
> In the case of the Rolls-Royce Wankel Diesel, the fuel-air mixture is first compressed by the lower rotary, and the output of that engine (which would be like the exhaust valve of a conventional rotary) sends the compressed diesel/air mixture to the intake of the smaller upper rotary engine, where it’s compressed to ignite like a regular diesel engine.
Seems like it had the same issues that have always plagued rotaries, primarily with apex seals.
https://jalopnik.com/this-might-be-the-weirdest-engine-rolls...
I mention that because 60% efficiency on a 70F day requires a heat source of at least 900F.
This one reason why, in piston engines, larger pistons ate more efficient. Less heat loss through the walls
Almost one third of all greenhouse emissions come from transportation, which is the same as saying from ICE's. There are 2 ways to reduce that: replace ICEs with electric motors, or increase their efficiency. If you manage to double the efficiency of ICE's, you're doing as good as replacing half of the ICEs with electric motors. If you increase their efficiency by 20%, it's like replacing 20% of the ICEs with electric motors.
So, yes, you could certainly revive ICEs, but only if you dramatically increase their efficiency.
Now, a typical ICE has an efficiency of 25%. Nissan is working on an ICE with an efficiency of 50% [1]. That thing can save ICEs. Anything else, it's just word spinning.
[1] https://www.greencarreports.com/news/1131416_nissan-claims-5...
Unlike one power stroke per two revolutions? That engine has one stroke lasting a full revolution, modern four-stroke has power stroke lasting half of revolution, every two revolutions.
As of awhile ago, the LiquidPiston folks were working on improving longevity. Building a test engine that works is an impressive achievement, but getting it to last also requires a lot of careful engineering and testing.
There is no going back now. The age of new repairable cars has ended.
Batteries can have any power density you want its really more of an aspect of pack design.
The only defficiency of EVs is the energy density of batteries.
Motors: high power density
Batteries: medium to high power density, low energy density
ICE: low to medium power density
Gasoline: high energy density
Their website is long on promises short on details. No pictures or videos of their purported prototype.
The Motor Trend article[0] they link has a video of it being used in a ducted fan configuration. They might be able to avoid particulate intake to the engine itself (just like every other reciprocating engine with a filter), but sandblasting the fans or smacking them with a bird is pretty guaranteed to cause damage to the prop or fan at a minimum, and still has a likelihood of torqueing the engine in a way that damages the seals and bearings.
It's cool, it's promising, but no prototype and high claims? I am extremely skeptical.
[0]https://www.motortrend.com/features/might-new-concept-rotary...
edit: I just saw that their video has all of five seconds of an extreme close up of their prototype. I'm still not persuaded.
https://www.engineering.com/story/update-wankel-20-the-retur...
Mazda also released the spark-compression gasoline engine in the current round of Mazda designs. PHEVs allow gas engines to run on the Atkinson cycle.
Range extenders or an emergency recharger is about all you can use them for.
We do need an ultracompact engine for what I think is a sweet spot for consumer transition: 100 miles of LFP battery range + a compact range extender gas engine until charging infrastructure is ready and fast charging works reasonably well.
How would a Wankel that only had to do recharging (fixed gear, etc) serve in that fashion?
A scaled down rotary that was portable might be a good "oh shit I ran out of charge" portable recharger, but then again, a fuel cell might be better for that.
0. https://en.wikipedia.org/wiki/Camless_piston_engine
1. https://www.thedrive.com/news/26267/koenigsegg-prepping-1-1m...
The sooner we can get the Walmart warriors into adult Power Wheels the better.