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Interesting link.

While the Mazda engine is subject to the limitations of the Otto cycle, it adds some new limitations of its own. It runs hot, has apex seals, and tends toward incomplete combustion.

The engine you linked to is interesting, the Brayton cycle is used in some land propulsion systems (mostly heavy military vehicles) using conventional turbine engines. I'm guessing that they are using rotary compressors and expanders to avoid high machining costs associated with fan-type compressors and turbines. I'm sure that some very smart people are working on the star rotor engine, but I wonder what would happen if they replaced at least the compressor with a fan.

If you think the star rotor is interesting check this out: http://www.mcmastermotor.com/concept.htm

Not that the McMaster motor is without problems of its own. It still needs seals, and operates (I think) in the diesel cycle. They also talk about using hydrogen to power their motor, I'm guessing that there are some insane compression ratios in that thing as currently designed, but it looks to me that the design of the McMaster motor is more flexible than either the Wankel or star rotor engines. I don't know all of the limitations, but I have to wonder if it might not be more economically viable if it ran on diesel.

the previous link wasn't very clear in how it was supposed to work.

http://www.roymech.co.uk/Related/Pumps/Rotary%20Po sitive%20Displacement.html

is a lot clearer the first diagram appeared to show two pistons attached to the wobble plate in reality they are pushed against the plate by springs and the pistons track in and out following the contour of the wobble plate.

armed with this information

http://www.eaa.org/benefits/sportaviation/october2 003.html

shows some engines developed using wobble plates

and heres a better animated one

http://www.mcmastermotor.com/technical.htm

it claims on this page this engine in equivilent to an 8 cylinder engine.

There are a lot of things in this post to comment on. Generally, the situation is a catch-22. In order to make alternative energy sources / carriers cheaper, there has to be a demand for it, but in order for there to be a demand, it must be cheaper. The bottom line is that if we sit around debating the pros and cons of the different technologies, in the end we'll get nowhere.

There was an article posted here years ago which mentioned an inventor who has invented a hydrogen and oxygen powered rotary-style engine which is far more efficient than today's engines. Although his web site has not been updated in a very long time, it has some interesting ideas.

Article: http://www.business2.com/b2/web/articles/0,17863,5 14029,00.html

Web Site: http://www.mcmastermotor.com/about_us.htm

This may be somewhat off topic but may be relevant.

There was a reference to an article here a long time ago about a guy who was building a rotary engine which used hydrogen and oxygen as fuel and exhausted water. When you park your car, it plugs into solar panels which 'recharge' the water back into oxygen and hydrogen.

The article is still at http://www.business2.com/b2/web/articles/0,17863,5 14029,00.html and the web site for the invention is at http://www.mcmastermotor.com/engine.htm. The web site has not been updated since 2001, though.

This reminds me of a nutating (wobbling, essentially) sphere engine I read about at McMaster Motor.

I have a little more faith in McMaster's credentials, and the design seems more realistic.

Bah!

What would I like to see succeed?

How about the McMaster Motor? Two moving parts, light weight, innovative fuel source (but could be run off of steam in a pinch!), simple design - similar to a
Nutating Disk Displacement Meter.

Or, how about the Ball Piston Engine? An interesting design that looks more like a ball bearing than an engine. The nice thing about the engine is the "standard" parts - ie, all the cylinders look the same and operate the same, parts can be swapped almost at will. I would bet one of these could be prototyped using parts from Home Depot.

Yet another twist on engines, The Henry Engine is a rotary steam engine, not a turbine.

These are the kind of mechanics I want to see in a future car. Something different, maybe based on older tech (I am sure all of these examples I have given are based on older principles/ideas).

Another kind of engine, one that I think would actually make for a better and lighter hybrid vehicle: the free-piston engine. Basically this engine consists of a piston that is fired on both side (alternatingly), with the shaft that extends through the piston driving linear hydraulic pumps, with the hydraulic fluid being conveyed in the normal manner to power hydraulic motors which drive the wheels. I would suggest that instead of the piston driving pumps (more indirection=more friction=more heat=wasted energy), make the piston a magnet of sorts, wrap a coil around the cylinder (or make the cylinder be the coil), and extract the electricity directly as the piston is bounced back and forth between the ends. I would think such a system could be made to use the fuel in a super-efficient fashion (not perfect, but better than a standard piston engine). I can think of a number of design issues (ie, how to make a piston be a magnet with the heat of combustion working at odds, among others) - but these can be worked out.

Think about how (relatively) simple a free-piston engine is - a tube, a piston inside the tube, and inlet/outlet ports (and controlling valves) plus spark plugs at the ends. I would think a good spud-gun builder could build a prototype (that would run for a while, then melt from the heat) from ABS/PVC pipe, sprinkler valves, etc from Home Depot - make the piston from a chunk of wood with steel end plates, magnets set in holes around the edge, wrap wire around the middle. Control the solenoid valves and plugs with reed magnet switches, maybe some relays (or Hall Effect sensors) - hmm, if I had the time I would do it myself!

Someone should try to build this - I guarantee you will get /.'ed in seconds if you do (heck, it will be a better story than another one about case mods)...

Take a look at this: "...equivalent to an eight-cylinder engine..." then on this page they quote: "...equivalent to the six-cylinder engines..." then, on the same page they say, "Also planned is a four-cycle, gasoline-powered version, which will burn substantially cleaner than a traditional gasoline-powered engine." Four cycle? What? How can there be four cycles involved in a "wabble" plate. I can see multiple "wabble" plates, but would that then not be equivlent to multiple cylinders?

I will believe it when I see it. For the time being, looks like a nicely put together practical joke to me. People have been claiming for years that they have invented a perpetual motion machines. Once again I say, "show me your code."

Sorry, but there is no such thing as a free lunch, and if something looks too good to be true, it probably is.

It is just sad that many computer geeks see information like this and want to tell everyone else about it in the same way as some of my clueless friends will pass around emails warning you to check phone booths for needles in the coin return slot with a note stating that you now have aids. They are very sincere in the fact that they beleive they are helping and feel this is true. I want a review of this technology from someone whos focus of study is specifically such technology.

/RANT

Take a look at this: "...equivalent to an eight-cylinder engine..." then on this page they quote: "...equivalent to the six-cylinder engines..." then, on the same page they say, "Also planned is a four-cycle, gasoline-powered version, which will burn substantially cleaner than a traditional gasoline-powered engine." Four cycle? What? How can there be four cycles involved in a "wabble" plate. I can see multiple "wabble" plates, but would that then not be equivlent to multiple cylinders?

I will believe it when I see it. For the time being, looks like a nicely put together practical joke to me. People have been claiming for years that they have invented a perpetual motion machines. Once again I say, "show me your code."

Sorry, but there is no such thing as a free lunch, and if something looks too good to be true, it probably is.

It is just sad that many computer geeks see information like this and want to tell everyone else about it in the same way as some of my clueless friends will pass around emails warning you to check phone booths for needles in the coin return slot with a note stating that you now have aids. They are very sincere in the fact that they beleive they are helping and feel this is true. I want a review of this technology from someone whos focus of study is specifically such technology.

/RANT

The seal problem is actually easier than I thought.

After more carefully looking at a different animation of an operating engine on the McMaster web site, I see that the outer path described by the nutating disk defines a sphere, not a cylinder. (Duh!) The point of tangency where the disk edge contacts the spherical inside of the motor remains at a constant 90 degrees. Therefore, the seal travels an almost flat surface on the inside of the containing sphere, and can therefore be more like a conventional piston ring.

Now, if there is an oil-delivery system travelling through the axle and disk and out the edge (between two seals) then I agree with the original poster that oil that will be burned.

Unfortunately, I'm long since removed from my organic chemistry days, so I can't answer how the ammonia and/or nitrous oxide compounds might react to the tramp oil on the sphere's wall. It almost certainly will cause most of the pollution problems with this engine, either by causing undesirable reactions with the pre-ignition fuel components (preventing them from achieving 100% combustion) or by simply being burned and the waste being exhausted.

Whatever the results, it's much more likely to be eco-friendly than the good-old-fashioned hydrocarbons we burn today. Certainly the fuels he describes will combust more cleanly.

John

The McMaster Motor website, describes the engine running on nitrous oxide and ammonia (essentially hydrogen and oxygen, with a bit of nitrogen thrown in to make things easier and safer to handle = 3 N20 + 2 NH3 = 3 H20 + 4 N2 + kaboom ).

Added bonus: Nice little animations to show how the combustion system works.

http://www.mcmastermotor.com/technical.htm
http://www.mcmastermotor.com/concept.htm

The McMaster motor is based on spherical geometry and has only two moving parts - the shaft and ball assembly, and the wobble-plate assembly.

1) the annular wobble-plate is attached to (or part of) the ball, and the ball moves the drive shaft via gears, or
2) the ball is attached (or part of) the drive shaft, and the annular wobble-plate moves the ball via friction.

http://www.mcmastermotor.com/technical.htm
http://www.mcmastermotor.com/concept.htm

The McMaster motor is based on spherical geometry and has only two moving parts - the shaft and ball assembly, and the wobble-plate assembly.

1) the annular wobble-plate is attached to (or part of) the ball, and the ball moves the drive shaft via gears, or
2) the ball is attached (or part of) the drive shaft, and the annular wobble-plate moves the ball via friction.

http://www.mcmastermotor.com/technical.htm
http://www.mcmastermotor.com/concept.htm

The McMaster motor is based on spherical geometry and has only two moving parts - the shaft and ball assembly, and the wobble-plate assembly.

1) the annular wobble-plate is attached to (or part of) the ball, and the ball moves the drive shaft via gears, or
2) the ball is attached (or part of) the drive shaft, and the annular wobble-plate moves the ball via friction.

http://www.mcmastermotor.com/technical.htm
http://www.mcmastermotor.com/concept.htm

The McMaster motor is based on spherical geometry and has only two moving parts - the shaft and ball assembly, and the wobble-plate assembly.

1) the annular wobble-plate is attached to (or part of) the ball, and the ball moves the drive shaft via gears, or
2) the ball is attached (or part of) the drive shaft, and the annular wobble-plate moves the ball via friction.

http://www.mcmastermotor.com/technical.htm
http://www.mcmastermotor.com/concept.htm

The McMaster motor is based on spherical geometry and has only two moving parts - the shaft and ball assembly, and the wobble-plate assembly.

1) the annular wobble-plate is attached to (or part of) the ball, and the ball moves the drive shaft via gears, or
2) the ball is attached (or part of) the drive shaft, and the annular wobble-plate moves the ball via friction.

http://www.mcmastermotor.com/technical.htm
http://www.mcmastermotor.com/concept.htm

The McMaster motor is based on spherical geometry and has only two moving parts - the shaft and ball assembly, and the wobble-plate assembly.

1) the annular wobble-plate is attached to (or part of) the ball, and the ball moves the drive shaft via gears, or
2) the ball is attached (or part of) the drive shaft, and the annular wobble-plate moves the ball via friction.

The other technology discussed here is photovoltaic (solar-electric) conversion of water to hydrogen for combustion.

The edge of the rotating "wobble plate" has to form a tight seal against the cylindrical, outer casing. Without an effective seal, combustion products leak across the plate, reducing power and (being hot) eroding the surface of the casing and the edge of the wobble plate.

Any point on the edge of the wobble plate is describing a long, looping path on the surface of the casing. If any pinpoint on that edge erodes it creates a path for hot gases which would quickly erode a wider and wider path.

Gas sealing was the downfall of the Wankel rotary and it is an even worse difficulty here. This engine is just not practical on that basis alone.

Since you've taken apart your Mazda, you're familiar with the Wankel engine. Now go to McMasterMotor and you'll see something completely different.

They've got some more info on the engine (including a neat little animated pic of the theoretical engine in operation).

According to his website (which I found from another comment), the fuel is actually nitrous oxide and ammonia, does not require air, and exhausts air (nitrogen) & water.

Looking at it helps me understand the way it works. I don't know if this will ever come to fruition, but I sure hope it does. Even if it doesn't, he's a revolutionary thinker with a significant record of success, and deserves our praise and respect for that.

Looking at it helps me understand the way it works. I don't know if this will ever come to fruition, but I sure hope it does. Even if it doesn't, he's a revolutionary thinker with a significant record of success, and deserves our praise and respect for that.

Okay, so nobody's bothered to check up on google, yet. His web site includes a lot of more detailed information. Check it out, then let's discuss what's there, not just what's in the article.

Yes, the guy's a little, er, fringey -- one of his other projects is an antigravity machine. I'm not saying such a machine is impossible, just that I'd not expect anyone who's not, say, Stephen Hawking, to come up with one.

That bit of weirdness aside, what do people think about the engine itself?

First, the fuel. The article implies that it uses Hydrogen. We've discussed to death the problems with using straight hydrogen as a fuel, which ultimately (putting aside safety and infrastructure issues) comes down to energy density -- pound for pound (or liter for liter), Hydrogen gas just doesn't pack as much punch, specatcular disasters caught on tape notwithstanding, as gasoline. However, the page talks about using a mixture of Nitrous Oxide and Ammonia, ignited with a glowplug, not straight hydrogen. It does speak of a catalyzed reaction being researched to derive the fuels from solar power, air, and water.

Questions: Is it likely that such a catalytic reaction exists? If not, will it take more fossil- or nuclear-fuel energy to create, using other reactons, the needed amounts of nitrous and ammonia? Would that added cost be worth it to reduce fossil-fuel emissions from cars? (let's ignore issues of infrastructure for now...)

Next, there's the design of the engine itself. Basically, it appears that it's an angled plate in a cylinder, with the reactive explosion happening first on one side (causing the plate to rotate around the axis it's mounted on), then on the other. Nifty idea, simpler looking than the Wankel rotary engine, and MUCH simpler than the internal combustion engine.

Questions: Can such an engine really operate, with any fuel? Could you really run it at many different speeds, and if so, how would you manage that? (I'm not personally convinced that you could do without a transmission). Would the "chambers" formed by the rotating plate provide any compression for the fuel (a major requirement for traditional engines)?

Let's not dismiss this entirely, out of hand, as a wacko idea. Look at the web pages in detail, ignore his strong claims and "past performance", and just focus on the ideas presented. I'm intrigued, but don't know enough about chemistry or mechanical engineering to pass any kind of judgement (and I suspect most of the people here don't qualify, either.) Those who do qualify...what do you think?

david.