The Cyclone
Cost to Develop: $2 million
Time: 8 years
Prototype | | | | | Product
As long as the internal combustion engine has been around, garage tinkerers have been trying—in vain—to best it. But Florida boat engineer Harry Schoell, a lifelong inventor with a portfolio of patents, thinks he’s got the answer, in the form of a reinvented steam engine.

But steam engines small enough to fit in a car don’t typically produce enough energy to drive it. Schoell’s design, called the Cyclone Green Revolution Engine, gets more power from the steam by making it so hot that it turns “supercritical,” a stage at which it behaves more like a liquid and expands far more than gaseous steam.
Although it can scale up or down, Schoell’s prototype is roughly the shape and size of a backyard grill’s propane canister. Inside a doughnut-shaped combustion chamber at the top, fuel—be it biodiesel, ethanol or gasoline—combusts with air continuously to create a 2,000°F tornado (hence “Cyclone”). Steam circulates around a heat exchanger until it reaches 1,200°F and then pipes into the engine’s cylinders to drive the pistons. As the steam cools, it’s recycled back into the system and reheated.
By zealously reusing every possible bit of heat, steam engines can convert up to 46 percent of incoming energy into torque. Most gas-powered internal combustion engines, in contrast, are only about 25 percent efficient. Schoell’s prototype also emits much cleaner exhaust than a standard gas engine; unburned fuel sits in the combustion chamber until the engine fires up again, and eventually nearly all the waste particles and unused fuel are incinerated.
Schoell’s company, Cyclone Power Technologies, has recently signed a deal to develop a Cyclone for lawn mowers and other garden equipment. And unlike most garage tinkerers, Schoell has even won the respect of the pros: In 2006, he won the Distinguished Automotive Engineering Award from the Society of Automotive Engineers for the Cyclone’s design.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.


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It's not an "internal" combustion engine -- it's an "external" combustion engine. The article is vague or misleading on that point.
The video would have been much better if we could have seen the engine work. I think many people who read PopSci are also interested in the details. How is the 'cyclone' generated in the combustion chamber? How is the steam pumped? What does it sound like? What are the 'green' implications? (It runs on 'any' fuel -- does that just mean gasoline and ethanol, or does it include diesel and wood?) He said there's no oil. Don't the pistons still need to be lubricated in some way, or is the steam a kind of lubricant?
I know answers to all these questions would require a longer article, but a few of them could have been answered without much extra text or video.
It's a great item however and Popsci.com is free, so I'm not really complaining. Just suggestions.
How about giving us a better idea of the power output--the 20 lb. propane canister size unit apparently develops enough horsepower for a lawnmower--oh, wait, it doesn't really say that.
But, the question is, how big a unit (approximately) would be needed for a car (and what kind of car?)?
Randy Kramer
You really had to pay attention due to the poor quality video.
The deionized water acts as a lubricant.
The unit they were looking at was a 300HP truck engine. It looked like it was a bit bigger then the average big block. Or maybe the size of a eighteen wheeler engine but I don't think so.
But in any case, Popsci should think about sending the camera guy back to high school. That video was terrible.
Those are great questions. If you have the time to log in, read and post these questions, then maybe you could go to http://www.cyclonepower.com. The site answers all the questions you have in-depth. I have been following this company and its tech. for some time now. It is very interesting.
It is more than difficult to beleive that the US Navy does not know steam engines. It is even more difficult to beleive the heating of water to the temperature stated. It is possible, but with an enormous penalty is fuel. The heating of 1 pound of water is the equivelent to 1BTU. A bearing material and no friction, and water as a lubicant just seem to be a lot of perfect.
We are sure of one thing, a laborotory is a lab. A lot of experimental starts have been attempted. With the appropriate results.
Harry is on to something here, we've know for years the power of steam and even superheated stream that is used industrialy. In the last decade we have seen leaps and bounds in engine technology, metal technology, and metallurgist, have made great strides in new materials. I think Harry's engine is a display of the technology.
Yes the video was poor and yes Harry was vague in his discription of the engine. However, if you invented this seemingly new hi-tech steam engine, and in explaining it, trying not to give away patented ideas of it's running condition, and explaining it's running theory to people that only know and are exposed to old principles and theory
then you to would limit the information given about your product as well.
A steam engine is an absolutely legitimate power plant, and much more efficient than an ICE. If one were to pay attention to the video, one would learn that this engine runs at a much LOWER temperature than an ICE. Remember, water boils at only 212 degrees F. Modern bearing materials make it possible for the superheated water to act as the lubricant. And because superheated steam generates nearly 100% torque, the engine does not have to rely on high speed rotation, the cause of much of the heat in an ICE. Because of the lower running temperature this motor is able to do without oil lubrication, radiator and coolant, and really much of exhaust system, not to mention, because of the tremendous torque steam generates, it needs no transmission.
Really this motor is just an update of Doble's steam engine from the 20s, see: http://www.jaylenosgarage.com/video/video_player.shtml?vid=213453
I had the great honor of getting to meet Harry a couple years ago at his shop down in Fla. At the time he was building the prototype you see in the video. As he said in the video, it is able to run on anything that can burn. At the time he was using citrus oil pressed straight out of orange peel. It will burn any other type of sustainable oil as well, soy, corn, flax, potato, and yes, hemp, not to mention gasoline, kerosene, diesel, and even hydrogen.
it would be a great replacement for todays ICE. It uses far fewer resources than the current transportation standard, and is infinitely more flexible than an ICE no matter what GM tells you. I'm glad to see Harry is finally getting the recognition he deserves out of this project. Spread the word.
I wonder how much water it leaks. Sealing is always an issue with this type of engines. Also, didn't he say it uses deionized water. Deionized water dissolves a lot of things, including engine parts.
Ron S.
Why would a car be too small to contain a steam engine big enough to move it when a gigantic heavy train, plus cars, is capable of plenty speed (in steam trains of yesteryear)
Steam was the method that moved the world....look the world over for steam driven power....not just the USA, it was every where in the world...it moved trains and alot of weight,city's used it for a heat source, factories used it to manufacture..anyone not sure of the potencial power it contains....just look to the past!!
Nothing more than a steam engine. The so-called "waste-heat" which is supposed to make this thing sound like it's actually saving energy or recovering it, is the steam generated by the BOILER (nothing new there) and the "waste-heat engine" is nothing more than a radial piston engine powered by steam. Radial engines have been around since World War 1. Unless I'm mistaken, if you look at the tubes going into the cylinder heads (starts to sound kinda ordinary now, don't it?!) you'll notice they only feed the top of the piston. Single acting cylinders, meaning half as efficient as double-acting pistons, where there is power in both directions of the stroke, which would create much more torque and efficiency.
This article is deceptive; to quote-"But steam engines small enough to fit in a car don’t typically produce enough energy to drive it. " Ever heard of the Stanley /steamer?! The Doble?! C'mon, guys do your research!!!
Steampunk, of course the Waste Heat Engine will save energy by using heat otherwise lost to generate steam for the engine. What the WHE provides is a cost-effective means. We don't see small heat recovery heat engines today because they would be too expensive. Also, these engines are not standard radials. The old radials have an odd number of (offset) cylinders while the Cyclone has an even number of cylinders with axes in the same plane. This allows multiple cylinders to drive a single crank making for a simpler and more compact design. Finally, the single-acting design makes for a simpler and more compact engine by avoiding the use of crossheads and piston rods/seals, and allows much shorter cylinders to be used. A single-acting engine is also easier to design and build for high speeds as there is less mass in the reciprocating components. This is not a problem where engine speeds remain low (as in the old steam locomotives), but high speeds are necessary to optimize efficiency in small steam engines (especially uniflows). Single-acting is the way to go in a modern steam engine, IMO.
Jay Leno has a steam car from the last turn of the century that could produce instant steam and match the power of any IC engine. The design failed because mass produced IC powered vehicles were cheaper to build. Mass production would bring down the cost of such steam powered vehicles. But there are other types of combustion powered engines that are being tested. Like using a small turbine to generate electricity in a all wheel drive hybrid vehicle. May the best design win. Still until all vehicles are powered by renewable energy sources, plug in rechargeable hybrid vehicles, the major threat of running out of mined and drilled combustion energy sources, combined with the rising levels of CO2, mercury, and other toxic chemicals in our enviroment released by burning of non-renewable energy resources, threaten society as we know it.
not too much knowledgeable about engines. just wondering if it was possible to link car battery to ignition coil to an electric burner which will heat the boiler which will run the engine and the engine will recharge the battery through an alternator. That way we will have a self sustaining steam engine. Not sure if its possible.
Steam engines are really attracting a lot of interest lately.
There's even an open source project going on: the Open Source Steam Engine Construction Set, which will include an Arduino to control the electronic steam injection.
You can take a look at its wiki page here:
http://bit.ly/ose-steam-engine.
And read more on what Marcin Jakubowsky, Robert Thomas and Nick Raaum are up to here:
http://openfarmtech.org/weblog/2010/08/steam-engine-prototype-1-design/
http://openfarmtech.org/weblog/2009/01/steam-age-meets-the-digital-age-open-source-steam-engine/
If cars that ran on steam were around one hundred years ago then why hasn't something better and more efficient been invented that runs on steam?