Looking To Better Engines Instead of Electric Vehicles 570
hlovy writes "Don Runkle thinks it's engines, not batteries, that will make automobiles cleaner and more efficient. 'We unabashedly say that we have the best solution,' says Runkle, the CEO of Allen Park, MI-based engine developer EcoMotors International. The startup, which brought in $23 million in Series B financing this summer from Menlo Park, CA-based Khosla Ventures and Seattle billionaire Bill Gates, has designed an opposing piston, opposing cylinder engine that uses fewer parts than traditional motors do and generates more power from each stroke of the engine, CEO Runkle says. He says the 'opoc' engine is smaller, lighter, and less expensive than the motors already out there, and a more viable option than switching automobile fleets over to electrical power."
Re:why not both? (Score:5, Informative)
Room for improvement. (Score:5, Informative)
There is still room for improvement of the internal combustion engine, one is variable compression.
However - a very limiting factor is that consumers aren't willing to pay for the technology, especially in the US where gasoline is dead cheap compared to many other places in the world.
Just look at technologies that have been created earlier - the Alvar Engine (variable compression with a small piston that rotates phase-adjusted to the camshaft, and is actually a assymetrical counter-piston engine), Smokey Yunick's Hot Vapor engine (heating the fuel beyond boiling point before injection) etc.
Diesel engines are also one of the more fuel efficient engines around at the moment. Efficiency up to 55%.
But what really consumes fuel in many cases is the stop&go traffic in cities. Even a short term accumulation of energy in a capacitor bank would help to keep that down. And vehicle weight is also an important factor. Aerodynamic drag is of course important, but only at highway speeds. In a city you can do fine with a shoe box.
So the future for cars is probably a combination of solutions.
Titanium horseshoes (Score:4, Informative)
History repeats itself. What's old is new again.
And why are we beating the dead horse that is ICE engines when we could be advancing other technologies? I wrote in a previous comment how it's very similar to new titanium horseshoes... great, but why?
Old Tech (Score:1, Informative)
"EcoMotors’ opoc engine is built with opposing pistons, opposing cylinders, and a single crank in the middle. Together, the components work to create a combustion power event with every revolution, unlike existing 4-stroke engines that combust every other turn, Runkle says.
So basically you made a two-stroke [wikipedia.org] flat-four. [wikipedia.org] Color me unimpressed. You're not even using Stirling [wikipedia.org] cycle. Tell me, how the heck did you get Bill Gates to give you money anyway?
Re:energy density (Score:3, Informative)
Yes, we can
http://en.wikipedia.org/wiki/Fischer [wikipedia.org]–Tropsch_process
When the USAF tried to get Congress to let them build a plant in Montana it has been blocked by Congress because it doesn't reduce CO2 emissions, however some processes can be near carbon neutral, Henry Waxman won't allow it unless it's carbon negative
http://spectrum.ieee.org/aerospace/aviation/us-air-force-syntheticfuel-program-in-limbo [ieee.org]
With the House going Republican, I bet the USAF project comes back to life in '11-13
Re:opposing cylinders? (Score:3, Informative)
Subaru? A gentleman by the name of Ferdinand Porsche (perhaps you've heard of him) sold/licensed the original Boxer engine design to Subaru.
Nice video interview with developer (Score:5, Informative)
Tried to figure out how this thing worked and I found this video here: http://www.engineeringtv.com/video/Opposed-Piston-Opposed-Cylinder [engineeringtv.com]
Some good technical questions and answers, as well as a working illustrative model of the engine.
Re:Diesel (Score:3, Informative)
Re:Nothing revolutinary? (Score:4, Informative)
the few words with some real content in it makes it seem like this is just a two-stroke boxer engine.
You should watch the video linked in the article, it really is not just a 2 stroke. It's an opposed piston/opposed cylinder design - think a regular flat twin, but imagine a second pair of pistons moving where the valve head usually is. You can't easily see it in the picture in the article, but it is a neat idea. If it works, it could be cool. If it works.
Summary (Score:5, Informative)
The article is light on details, but there's details elsewhere.
The OPOC engine is a horizontally opposed two cylinder two-stroke engine. As a cylinder in a two-stroke engine has a power stroke on every revolution instead of every second revolution, this engine has very high power density compared to a four-stroke engine of the same size.
Traditionally, two-stroke engines have had very poor emissions. Since the exhaust and intake strokes are not separate, the intake mixes with the exhaust to some degree. This means that some of the intake fuel goes out the exhaust unburned, and some of the exhaust remains in the cylinder with the intake charge, reducing peak temperature. This engine, however, uses assisted HCCI [wikipedia.org] with a diesel injection system, meaning the fuel is introduced during compression instead of intake, so unburned intake fuel does not cross over to the exhaust. (I'm not clear what the "assisted" part is in the assisted HCCI. Perhaps there's a spark plug that's only used during low-power, lean burn conditions?)
The cylinder pairs are intended to be balanced and stackable, so that multiples can be connected together for higher output. TFA suggests that it might even be stacked with an electric motor for low-speed operation.
I imagine these would be very useful for a hybrid, despite the summary title. Unassisted HCCI engines have a small power range, but this would be perfectly fine for a series hybrid generator motor running at a fixed RPM for charging.
Re:Old Tech (Score:4, Informative)
That was my first though too. "It's just a boxer."
If you watch the little video linked to from the article (and I emphasize little, what is that, 160x120?), they show you it's like a boxer but the cylinder heads (I guess) move in opposition to the pistons. It's a little like having two pistons that would hit each other on the head in the shaft, both tied to the crankshaft.
I'm a little unclear, I don't have sound on my computer so I could only watch the little animation.
Re:opposing cylinders? (Score:5, Informative)
Like a VW, Subaru, or BMW bike? This is new?
Ok, they may be taking this to a new level, but this design has been around for quite a while.
No. I thought the same and wondered why it was different from a flat 4 layout. This has two pistons per cylinder, each pushing away from each other. It's also an advanced two-stroke. (I remember in the late 80s and early 90s when all the talk was about how two-strokes were going to be the next big thing.)
You need to watch the linked video [ecomotors.com] to see how it works. It's actually kinda cool. Each pair of opposing cylinders can act as an independent unit, so you can shut one unit down when you need less power. The guy claims significant fuel consumption savings.
Re:opposing piston, opposing cylinder engine (Score:5, Informative)
The VW Beetle used a horizontally-opposed engine, which is not the same thing as an opposed-piston engine. In an opposed-piston engine, each cylinder is double-ended, with a piston at each end and no head. A horizontally-opposed engine uses ordinary single-ended cylinders with a head and one piston.
No, I don't know anything about this stuff. I just know how to use Google and Wikipedia.
Re:Old Tech (Score:3, Informative)
So basically you made a two-stroke [wikipedia.org] flat-four. [wikipedia.org]
He didn't. Go back and watch the video. It's not a regular flat 4. It has two pistons per cylinder, each pair of cylinders acts as a unit that can be shut down when energy needs are smaller.
Re:So (Score:3, Informative)
Especially since they give little details as to what is so special about their engine.
"Opposing piston, opposing cylinder" is nothing new and is known for being good for improving balance and reducing vibration. See: Porsche Boxster (Flat-4?), Porsche 911 (I think most if not all 911s have a Flat-6), all Subaru engines (Flat-4 or Flat-6, called "H4 and H6" by Subaru to indicate that they are horizontally opposed engines), and nearly all modern piston aircraft engines.
There's nothing fundamentally good about this design as far as fuel economy goes. In fact, Subaru is a bit behind in terms of piston engine efficiency, although it's hard to make an apples-to-apples comparison of engines, as all Subarus are AWD, and AWD is known for being somewhat detrimental to fuel efficiency on a system (e.g. vehicle) level.
Now for engine efficiency itself, GDI is leading to significant improvements in piston engine efficiency. (See Ford EcoBoost, which is a turbocharged GDI, and the new Hyundai Sonata GDI engines). They aren't as efficient as diesel engines (While they have a higher than traditional compression ratio, they're still lower than diesel), but do have the benefit of reduced pumping losses that diesel does (Note: this particular benefit negates one of the benefits of hybrid vehicles, which is keeping the engine outside of a state where it experiences significant pumping losses), without the NOx and particulate emissions issues that diesel engines do.
Re:why not both? (Score:5, Informative)
Re:opposing cylinders? (Score:2, Informative)
Re:opposing cylinders? (Score:3, Informative)
Having finally found some details, it is quite a bit different from the horizontally opposed approaches of Subaru/Porsche/VW/Textron Lycoming/Continental (the latter two are aircraft engine manufacturers).
However, it doesn't seem "simpler" to me - it appears to require three piston rods per cylinder (one for the inner piston, two for the outer - a single rod for the outer would result in some significant torque on the pistons from having an edge-mounted rod. Also, this means you have crankshaft rods going OUTSIDE of the engine block.
All in all it looks to be a hell of a lot more complex than a traditional one piston per cylinder design.
opposing PISTON engine (Score:3, Informative)
Now if someone would just rear-mount that in a cute little chassis, maybe one that looked kind of like a bug or something...
What do you mean? Like those cute little minesweepers [wikimedia.org] or cute little locomotives [wikimedia.org] that have been powered by opposing piston [wikimedia.org] engines?
Re:So (Score:5, Informative)
"Opposing piston, opposing cylinder" is nothing new and is known for being good for improving balance and reducing vibration. See: Porsche Boxster (Flat-4?), Porsche 911 (I think most if not all 911s have a Flat-6), all Subaru engines (Flat-4 or Flat-6, called "H4 and H6" by Subaru to indicate that they are horizontally opposed engines), and nearly all modern piston aircraft engines.
You're missing half of the picture. The engines you list are all traditional four strokes. This one has an "opposing piston" above each traditional piston, where the valve head should be, moving in opposition to the standard piston (to increase compression, I guess). It's absolutely a different design.
Re:So (Score:5, Informative)
If you go to the site he has a bit more info including a graphic rendering of the engine >> EcoMotors International [ecomotors.com]
As I understand it, "traditional" flat engine, or opposing cylinder engine technology uses multiple crankshafts and cylinders and are often based on two-stroke engine technology. Certainly none of the examples I saw or read about in the wikipedia article (Opposed-Piston Engine) seemed less complex, nor efficient. [wikipedia.org]
This engine, uses two cylinders, each containing two opposing pistons, and only a single crankshaft to obtain 4-stroke emissions benefits without the added complexity of synchronising multiple crankshafts. Also, they're proposing that multiple such powerplants could be daisy-chained together to provide additional power when it is required. In theory, 1-4 of these modules connected thusly could give you performance up to that of an 8cy car, but use as few as two cylinders when the extra horse-power isn't necessary (by "turning on" extra modules as necessary, then turning them back off again when it isn't).
In theory at least, that should radically improve the available efficiencies of modern engines without needing to alter the existing fuel-distribution network, and without a loss of available horsepower when such is required. In that light, I would say it does represent "something new" (as opposed to your assertion to the contrary).
-AC
Re:Old Tech (Score:3, Informative)
They're not using the Stirling cycle because Stirling engines are very heavy (and have poor transient performance), and are thus a very poor choice for transportation applications.
They're one of several companies looking at opposed-piston (not simply a flat-four, but two pistons per cylinder) two-stroke engines (Achates Power [achatespower.com] is another significant venture-backed player), because the power-to-weight ratio advantages there are substantial, if issues with lubrication, cooling, and combustion quality can be solved well enough to bring them in line with conventional 4-stroke reciprocating engines in quality.
Re:why not both? (Score:5, Informative)
Nitpick: railroad serial hybrids don't use battery power storage for propulsion. They use a motor-generator fed from a diesel. The diesel is governed at a constant RPM where it has peak efficiency. The motor-gen set acts as a gearbox and clutch -- all electrically controlled. The motors can be installed directly on the bogeys -- you then don't have universal joints to maintain.
Re:opposing piston, opposing cylinder engine (Score:2, Informative)
...or you need a big, thick, heavy, super-strong rod to handle high loads (power) and vibrations (rpm). ... In fact they're over 100 years old.
I'm not an engineer of any sort but it seems to me you've completely ruled out super-strong modern alloys. 100 years ago they would use heavy iron or steel, likely killing efficiency entirely, but that has changed dramatically. If they can create super-light, super-strong alloys then isn't this argument essentially moot?
That being said, I see the future in electric vehicles personally. But more power to anyone who can come up with more efficient ways of doing anything we do now.
Re:why not both? (Score:3, Informative)
Isn't this basically a boxer motor? Granted, from the picture, it loosk quite a bit smaller than most boxers, but boxer motors are, as they say, a real bitch to mount.
These have been around for a long time, and would have a number of problems all their own.
Re:So (Score:3, Informative)
Re:why not both? (Score:5, Informative)
You mean like previously discussed here? [slashdot.org]
Which was reported here. [cnet.co.uk]
It's an electric vehicle with micro-turbines powering the electric generators if the car travels past the 68 mi single charge limit... or if you want the extra boost to do 0 to 60 mph in 3.4 seconds.
Oh, and it should be capable of accepting multi-fuels, so we (in the US) don't have to wait for the lift on extremely high EtOH import tarrifs while we also subsidize our corn -> EtOH program or wait for industrial research to fund (and patent) biochemical oil reactors (i.e. algae to diesel), or any of the other promises which trivialize the three laws of thermodynamics (enthalpy, entropy, and politics).
Re:energy density (Score:4, Informative)
Waxman is out as of tomorrow or whenever the new congress critters get swored in.
Re:why not both? (Score:1, Informative)
Isn't this basically a boxer motor?
Yes, its a boxer, suitable for plugging into any Subaru or flat-engine Porsche, but not many other current vehicle architectures.
Video interview with the EcoMotors designer here,
http://www.autolinedetroit.tv/journal/?p=10723 [autolinedetroit.tv]
Re:why not both? (Score:3, Informative)
Not quite. This engine uses 2 pistons per cylinder. Basically, take a boxer, remove the heads, and link the cylinders into one, with a single spark. Both cylinders get moved simultaneously rather than alternately as a boxer does.
Re:energy density (Score:3, Informative)
Nope. Without batteries, electric motors run between 3 to 5 times the power to weight ratio of internal combustion engines. Electrics also provide high torque from 0 RPM, so they start better, and you don't need a transmission. That in turn allows them to more easily put that weight right down in the wheels, which improves the weight distribution of the vehicle and can eliminate losses from gearing and couplings.
The problem is the batteries; the problem has always been the batteries. While they can also be placed very low and so aid in the vehicle's overall stability, the bulk and weight is huge, and that is what tips the overall weight in favor of the ICE. The engines themselves, though... electric wins by a huge margin.
Re:Energy use per transport mode (Score:3, Informative)
These numbers may be approximate for goods, however they are wildly innacurate for passenger journeys. Some little used rail systems actually average worse, in terms of co2 emissions per passenger, than single people in their cars. It all comes down to how many people are using the service - Full planes are better than single people in their cars too.
Re:opposing piston, opposing cylinder engine (Score:3, Informative)
The problem is buckling. The metal is so flexible that a slight lateral disturbance can cause an axially loaded member to collapse. To prevent this, the member is made much thicker than you would need just to support the compression.