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The Next Generation Hybrid

After re-engineering a 100-year-old design, Scuderi has now added a new twist to their Split-Cycle engine. It now sports a small holding tank between the 2 chambers which is used to store compressed air. This chamber allows the motor to run in either standard mode or a high-efficiency mode.

While in normal operating mode, the first cylinder brings air into the chamber. After the air is compressed, it is forced to the firing chamber via a small channel build into the block. While moving through the channel, some of the compressed air is forced into the small holding tank. The rest of the air is then forced into the other chamber where it is combusted and then forced out of the motor during the exhaust stage. The process is repeated till the chamber is full.

Air-Hybrid TankAir-Hybrid Tank

Once the storage tank is full, the motor can be switched into high-efficiency mode. This utilizes the compressed air in the tank to initiate combustion. Doing so eliminates the losses of compression normally exhibited. It also uses less of the air-fuel mixture so fuel mileage is sports a noticeable increase.

Another benefit uses the weight of the vehicle to continue building pressure during braking, known as Regenerative Braking. The firing cylinder is turned off while the car remains engaged with the motor. This makes the compression cylinder continue storing air in the holding tank to use later. It also helps to slow the car down by producing back pressure in the cylinder.

Scuderi Air-HybridScuderi Air-Hybrid

The design is also compatible with a turbocharger. By recovering energy normally lost from the exhaust, air is forced into the compression chamber, rather than sucked in. By doing so, the engine does not have to work as hard which frees up energy and makes for smoother operation. The turbo configuration is ideal for stationary applications such as generators.

The most impressive part about this new engine is the ability to use the compressed air for more than just motor operation. It can be tapped into via a valve on the top of the motor and used to run air tools or cam-less valves. It can also be used to inflate tires and even aid in starting the vehicle in the case of a dead battery.

As gas prices go up and EPA standards become stricter, people are looking for more and more ways to improve fuel mileage and reduce emissions. The Split-Cycle Air Hybrid motor has proven its ability to meet and exceed these new demands. With so much to offer this new engine could easily rise to the top of the automotive industry and rewrite how we look at tomorrow's automobiles.

George Delozier
Motorized Innovations


Oct 25, 2007
by makeworldbetter
makeworldbetter's picture

I don't see how

The Split-Cycle Air Hybrid motor has proven its ability to meet and exceed these new demands.

"Proven"??  I don't see a actual engine running and some solid number.

Turbo charger or supercharger are just doing fine and theyare a lot easier to build than many more extra cylinders

Oct 26, 2007
by Anonymous (not verified)

It's the same number of

It's the same number of cylinders, they just fire every revolution on the power side.

Oct 27, 2007
by Anonymous (not verified)


They been saying this for years Scudri group. Just looking for more money to pump into a failed technology. The first engine was to be ready in 05 then 06 then 07 now 08. Investors are kept in the dark. No american company or Japan has Taken any interst in this. That"s a fact.

Nov 8, 2007
by Henry Gibson (not verified)

Scuderi Engine

The split cycle engine has been built and used years ago, but without the the careful valve control of the proposed Scuderi. The Scuderi is in fact simply the implementation of the Jet Engine with pistons and valves to maintain the pressure from compression to combustion. With many intake and many output cylinders and reed compressor valves on the intake cylinders, the power cylinder needs only cylinder wall ports as in a two cylcle engine. Stelzer, in Germany, uses no valves at all and just wall ports. Some two stroke cycle engines have been doing the almost identical operation for decades where the back of the piston is used for a precompression cycle, and the valving is done by ports in the cylinder wall. See the INNAS NOAX CHIRON free piston engine for an easy to see example. The largest ship engine in the world (RTA96-C) seems to use this principle as well. The air hybrid concept has already been implemented in at least two large CAES systems in Germany and the US. Large diesel truck engines and others were started by compressed air decades ago. There was a report of such an engine exploding when the air in the starting cylinder ran out and oxygen from a welding cylinder was substituted at a remote site.

Diesel engines have used Roots blowers for many years for what is in effect a partial split cycle. One company used a rotary screw compressor as the input compressor for a gas turbine engine.

The very successful production versions of Pescara's free piston engines have most of the features of the Scuderi and far fewer moving parts with separate compressor and combustion pistons, compressed air chambers for both the intake air and exhaust but a gas turbine power output. The gradually increasing capacity, increasing specific power, familiarity and efficiency of the standard diesel engine eliminated Pescara's engine. The same thing happened to Junkers free piston air compressors built for many years in Germany and Japan.

One emergency power supplier uses many standard air bottles in its system to supply a quick start turbine-generator that comes rapidly into operation while a flywheel-generator briefly carries the load. With its separate compressor and electrically charged heat exchanger it is a micro CAES.

The lack of any working prototype for many years has been a curious issue. The automotive industry is a hard industry to break into. Scuderi may be waiting for a large company to give it a lucrative intelectual property deal on a product that cannot be put into a production automobile for at least five years. Meanwhile research grants and capital infusions are paying for breakfast lunch and dinner. Its not as good a deal as some golden parachutes, but it is far far better than not eating. The air-hybrid idea came along just in time to prevent the need for a working prototype that would show some higher efficiency than a conventional gasoline engine but not much more than a good European diesel. One more obvious but unexplained modification of the cycle is still available for additional study before an actual engine has to be built, and gives time to get more research money. The compressed air car has been promoted in France for many years with several investors involved. The EPA-UPS compressed-air-hydraulic-hybrid drive is in revenue operation for over a year. FEV could have built a Scuderi prototype and tested it in less than a month and a car with another in less than a year. Perhaps Scuderi is using FEV software.

The very very high cost of hydrogen fuel cells will also keep its researchers in breakfast lunch and dinner for a decade or more. The nearly five decades of use of fuel cells in the space program has not brought them into the price performance range of lead acid batteries and electric motors and the grid. No one would buy any fuel cell on the market if it were not for a special project or had massive govenment support. The largest engine in the world is more efficient than any fuel cell now built and uses far less expensive fuel and fuel delivery systems. Both it and many fuel cells can be made even more efficient with Rankine heat recovery cycles familiar to the geothemal energy industry. It is interesting that the shaft speed of the RTA96-C is about the same as a hydro-electric turbine generator.

Major automobile companies have no need for efficiency in their engines or cars, in the US at least, because they do not pay the fuel bill. Higher efficiency can be gained simply by using smaller displacement versions of already existing engines with lower horsepower. At low loads, large engines have much lower efficiency because most of the parts are just creating friction. Selective operation of only some cylinders has been tried with success in some engines. A Large OPOC engine with clutches between cylinder pairs would reduce additional friction loss.

The original CITROEN had only two horsepower. The US market does not want efficiency it wants high rated horsepower. Not a single car sold in the US with an engine display shows the actual horse power at the wheels. A CALCARS Prius Plus has an average of 8 horsepower at the motor if it goes 30 miles in one hour at the claimed 200 watt hours per mile. But the TZERO claims less than 180 watt hours per mile are needed. This figure can vary by a factor of more than ten with the speed and the location. Continous operation at 100 horsepower would use a minimum of 7 gallons an hour for the best automobile engine and the amount could double for many engines. This compares to about 5 gallons per 100 horsepower-hours for the largest, most efficient piston engine in the world.

Never the less, I would like to see at least one Scuderi air Hybrid car built; it is a far better idea than the hydrogen fuel cell car and far more practical and cheaper.

Large nuclear powered chemical factories should be built near coal fired power plants to capture the CO2 and turn it into liquid fuel, perhaps butanol or diesel, for automobiles, trucks and locomotives. Eventually CO2 will have to be extracted from air to make liquid fuels. Zero Emission cars and trucks could now be built that capture CO2 from burning hydrocarbons at far less cost than the use of hydrogen fuel cells. The CO2 can be dropped off at service stations. Methanol made from coal directly is far cheaper than crude oil per unit energy. South Africa already makes diesel from coal. Germany made about half of its WWII fuel from coal. And if the production, refining and transportation energy cost of oil is considered, including the wasted natural gas, the use of coal derived fuels may not put any more CO2 into the air than does oil. Production of the liquid fuels right at the USA coal mine is less costly than shipping it from Arabia and refining it here.

The speculators, including the big US oil companies, have limited and cornered the oil market with the help of OPEC to raise the price of oil far beyond its production cost. Not one of the present oil companies or any of its affiliates should be allowed to participate in any way in the oilshale, tar sands or coal to liquids industry.

The willingness of the US population to go along with the extortion of the oil industry because we are rich and most of our energy is supplied from coal and gas, has improverished most of the world that does not have our resouces. The use of corn for fuel is starving them as well by increasing the world price for foods. The import duty put on ethanol from brazil should be reflected immediately by an equal per unit of energy import duty put on imported oil, and put into place permanently to allow the Coal to liquid fuel industry to prosper like the ethanol industry is.

Nuclear reactors can supply much or all of the heat required to refine liquid fuel from tar sands, oil-shale, natural gas or coal. Electricity from nuclear reactors or coal fired boilers is expensive because of the capital costs of the turbine, generator, tranformers, transmission lines, controls and very high pressure heat exchangers, but heat energy from nuclear reactors is cheaper than any other source. The price of refined uranium represents a small fraction of a cent in the cost per kilowatt -hour. A reactor made to operate at low steam pressure for the production of process heat is far less costly than current reactors and easier to control. Very cheap heat could be bled from existing reactors to produce ethanol from celulostic wastes including grass, straw, wood and news paper at much lower costs. Steam could also be provided for coal to liquids processes.

Special high temperature reactors that cannot have rapid run away reactions are being tested in China and could be used for higher temperature chemical reactions to produce fuels from water and carbon dioxide. It would not take much time to engineer a steam turbine powered heat-pump that could produce the high temperatures required for chemical processes from existing reactor steam temperatures. The equipment could be much cheaper than present electrical generators, but perhaps mass produced, very cheap small steam turbine-generators could use very cheap steam produced at lower temperatures at lower costs.

The plug-in-hybrid car is the most immediatly available solution to the automobile fuel issue. Conventional lead acid batteries can be used at low enough costs and advanced light weight lead batteries are available from EFFPOWER for fast acceleration along with the standard lead batteries. Firefly, Atraverda and others are on the verge of producing low weight lead batteries. Special computer management of the lead batteries can give them much longer life. Series hybrid operation with small engines removes any distance limitation, and mass production of motors and controlls will reduce their cost.

The ZEBRA battery is taking over some of the heavy electric vehicle market in England and is being introduced with the new TH!NK car. It has similar capacity to lithium ION but is better tested and understood. The high price is compensated by a lease agreement, but the cost of electricity is multiplied by more than three by the use of the battery. Still cheaper than gasoline. TH!NK is moving towards unproven lithium technology probably for greater distance and to avoid the need for constant high temperature in the ZEBRA which in Norway, even can be an unexplored advantage. TH!NK could cut the cost of the battery in half if they were to use a small engined series hybrid.

Lithium batteries are now still very expensive and heat sensitive, but will be used where engineering money and capital costs are not important.

The Prius is a production car that can be converted in a few hours into a plug in hybrid. CALCARS deserves support, comendation and attention for this proof. TZERO demonstrated a trailer that proved the infinite distance capability of the TZERO full electric for long trips. It is too bad that an EV1 was not fitted with a similar trailer. GM cannot say that there was no demand for the EV1 as they never tried to sell a single one like every other car that they introduced. No other production GM car was ever leased only to highly selected customers. The first cars off of any line are very expensive to build as were the EV1s but there has never been a selection test, other than money, for buying most of them. A modified HONDA EU3000is portable generator mounted in the trunk would have made a very useful plug in hybrid with even the lead battery versions of the EV1.

Nov 20, 2007
by Anonymous (not verified)

i think its a little crazy

i think its a little crazy my self, but i wonder if you could some how hook up a internal stationary rotory motor that ran off the crank arm like in a steam engine instead of that "dead" cylinder.?.