As for the inventors, they all seem to have a common goal – market disruption with their power plant that can be a drop in replacement to the conventional gas / diesel engines. Laudable goals indeed. And I know that these types of re-design / new technologies have been lurking in the market since the first automobile rolled off the coach assembly line. Why don’t we see more of the non-mainstream engines?

Risk of capital and market share. Deviate too far from the accepted norms, and customers won’t buy. There won’t be enough of a support structure once the engine passes through its warranty period. Neighborhood mechanics can’t work on them, the owner can’t get parts. If anything ever goes wrong with a non-standard engine, what do you do?

The only large scale production of a non-piston engine that I think of is the Wankle Rotary from Mazda.

So, do these alternative engines have a chance? Even if they have market disruptive qualities, it will take a brave automaker to take the plunge. As the automakers become more desperate, we might still have a chance to get one of these garage-designed engines.

So, I’ll try and keep a catalog of the novel engines that I run across. It ought to be interesting to see what the near future brings.

Brayton-Cycle Engine and Biomass Process for Mixed-Alcohol Fuels

http://www.greencarcongress.com/2006/04/a_braytoncycle_.html

A Texas A&M chemical engineering professor has developed a process to convert biomass to a mixed alcohol fuel that contains more energy than fuel ethanol. He has also developed a compact Brayton-cycle engine (the same thermodynamic cycle employed by jet engines) capable of being powered by any type of fuel—including his MixAlco mixed alcohol fuel.

Prof. Mark Holtzapple projects that his StarRotor engine, which is being developed by a company of the same name, could deliver efficiencies of 49–55% applied in a passenger car—about 2.5 to 3 times more efficient than a conventional gasoline engine.

Gun Engine

http://peswiki.com/index.php/Directory:Gun_Engine

Developed by a Canadian inventor, he is claiming that his engine is 92% efficient. He redesigned the traditional engine, with a goal of gaining efficiency from it. He proposes a transmission free vehicle, the mileage of which exceeds 200 miles/gallon of fuel. The vehicle runs on any fuel including Hydrogen and that is possible as the vehicle uses a novel engine. The novel engine has many things in common with a traditional engine: crankshaft, piston, induction and exhaust evacuation valves, yet it is different. The engine is different since its cylinder is cooled with injections of water. Another difference is that the energy release from fuel is much faster. The speeding up of energy release is through detonations of homogenous fuel, yet a shielding of piston from explosions of fuel, prevents over excessive stress in crank and related parts, as the explosion of fuel acts rather on an additional piston floating on air pocket. Also traditional camshaft and associated gears, to manipulate valves, are replaced with electromagnetic or hydraulic actuators, controlled with an electronic controller similar to that in robotics. The engine could operate in a four stroke cycle during starting and after reaching a preset speed it switches automatically to a novel twelve stroke cycles. Its torque is independent from speed, which eliminates need to employ energy wasting transmission. Also the engine converts heat, disposed in traditional engine through cooling, into extra work. The conversion does quadruple its efficiency. Both, the elimination of transmission and extremely efficient engine contribute to mileage of the proposed vehicle. In addition, a hydrogen generation from water that uses solar panel for electrolysis enhances the mileage above 400 miles/gallon during sunny periods, since the vehicle fuels itself with hydrogen and that costs nothing.

Six cycle engine

http://www.autoweek.com/apps/pbcs.dll/article?AID=/20060227/FREE/302270007/1023/THISWEEKSISSUE

Bruce Crower has lived, breathed and built hot engines his whole life. Now he’s working on a cool one—one that harnesses normally-wasted heat energy by creating steam inside the combustion chamber, and using it to boost the engine’s power output and also to control its temperature.

“I’ve been trying to think how to capture radiator losses for over 30 years,” explains the veteran camshaft grinder and race engine builder. “One morning about 18 months ago I woke up, like from a dream, and I knew immediately that I had the answer.”

The engine has yet to operate against a load on a dyno, but his testing to date encourages Crower to expect that once he gets hard numbers, the engine will show normal levels of power on substantially less fuel, and without overheating.

“It’ll run for an hour and you can literally put your hand on it. It’s warm, yeah, but it’s not scorching hot. Any conventional engine running without a water jacket or fins, you couldn’t do that.”

Indeed, the test unit has no external cooling system—no water jacket, no water pump, no radiator; nothing. It does retain fins because it came with them, but Crower indicates the engine would be more efficient if he took the trouble to grind them off. He has discarded the original cooling fan.

So far he has used only gasoline, but Bruce believes a diesel-fueled test engine he is now constructing—with a hand-made billet head incorporating the one-third-speed camshaft—will realize the true potential of his concept.

Research at the Hydrogen Engine Center Inc. is done in an early 1900s red brick armory at the Kossuth County fairgrounds.

There, a clean six-cylinder engine that looks like it could have been pulled from a Ford pickup has been running for 110 hours, not quite half the 300 hours it must continuously run for certification. The company, led by a retired Ford Motor Co. engineer, hopes to meet Environmental Protection Agency automotive 2007 emission standards.

All 81 parts are original Oxx Power, the brand name the company has given all its engines.

The engine can run on a number of fuels including hydrogen, ethanol, natural gas, propane or digester gas from landfills.

The company, started by Ted Hollinger, 65, is initially focusing on making more efficient, environmentally friendlier engines to replace those used in generators and in forklift trucks, airline ground equipment, irrigation pumps, tractors and buses.

Ford, General Motors and Chrysler have dropped industrial engine production as they've cut costs, leaving what Hollinger said is a ready-made market for his fledgling company.

"Our engine has to bolt in where the old engine went and can't be a thread off," he said. "If you do that and you make improvements in it so that it gets rid of emissions and it's more efficient, then I think people are going to like it."