May 3, 2006 On March 7, we wrote of the coming of Scuderi Group's
Air-Hybrid engine which claims the title of the world's most fuel
efficient internal combustion engine. The Scuderi engine makes its
European debut May 9 - 11 at the Engine Expo 2006 in Stuttgart, Germany
on a bit of a roll. With three additional worldwide patents recently
filed, the air-hybrid system potentially doubles the fuel efficiency of
today's gasoline and diesel vehicles and reduces toxic emissions by up
to 80 percent.
WTF is Oujdeivß?
better article, and I hope they've had running samples of the silly
thing, as they are supposed to start production in 2007.
Alex Magdaleno wrote:
WTF is Oujdeivß?
Here's a quote, where Sal Scuderi responds to some questions.
--- quote ---
There has been a significant amount of questions recently regarding the
Scuderi Engine, especially in light of the funding approved by the
federal government for its development. As president of the Scuderi
Group and one of the inventors of the engine, I thought it might be
helpful to try to clear-up some of the basic misconceptions about the
The Scuderi Engine does take advantage of the Miller Effect but not in
the method used by conventional engines. The Miller Effect in the
Scuderi Engine is achieved by having a longer stroke on the power
cylinder verses the compression cylinder - not by leaving the intake
valve open and supercharging the intake. However, this is only one
feature of the Scuderi Engine that helps to improve efficiency. From a
thermodynamic prospective the objective for increasing engine efficiency
is to somehow increase the area under the pressure volume (PV) curve of
the Otto Cycle. In the Scuderi Engine, the PV diagram is really two
separate curves - one for compression and one for combustion. It is the
difference in the areas under the curves that determines the efficiency
of the engine.
There have been split-cycle engines in the past. However, they have
never functioned as well as conventional Otto cycle engines for two main
reasons. First, their volumetric efficiency (how well air is pumped
through the engine) was never as good as a conventional design. This
caused the split-cycle engines to be larger resulting in a lower power
density and greater frictional losses especially on part load. Second,
compressing the gas in the compression cylinder and again in the power
cylinder (because they fired before top dead center) was doing work on
the gas twice. Consequently, they were never as efficient as a
conventional engine. However, if you could solve these problems, the
advantage of the split configuration is that it really is two systems in
one - a compressor and an engine. This gives you a great deal of design
The Scuderi Engine solves both problems by using some unique valve
designs and by firing after top dead center (ATC). It was the firing ATC
that was really the major hurtle that had to be overcome. Normally
firing ATC is considered bad practice in engine design; it causes
reductions in both power and efficiency. In the Scuderi Engine, the
combustion process begins with high pressure air entering the power
cylinder from the crossover passage. Massive turbulence is generated in
the cylinder causing very rapid atomization of the fuel-air mixture. The
result is a flame speed, or rate of combustion, that is twice as fast as
anything previously obtainable. Because of the rapid rate of combustion,
high pressures on the power piston are achieved even though the piston
is pulling away from the firing point. The effect is a split
configuration with actually higher efficiency and more power density
than a conventional engine. (The firing point for the Scuderi Engine is
between 10 and 15 degrees ATC.)
An interesting phenomenon that resulted from firing after top dead
center was reduced peak temperatures. Our power cylinder does have
higher average temperatures than a conventional system; however, its
peak temperatures are considerably lower. It is the peak temperatures of
combustion that generate the NOx emissions. Because Scuderi Engineï¿½s
peak temperatures are significantly lower, the amount of NOx produced is
up to 80% less than a conventional engine.
Because of its design flexibility, the Scuderi Engine makes it possible
to enhance efficiency and performance in ways that are difficult, if not
impossible, in a conventional design. The Miller Effect, for example,
can easily be achieved by increasing the length of the power cylinder.
Simply increasing the diameter of the compression cylinder can
supercharge the engine without any added equipment or complexity. (A
four-cylinder engine could give you the power of a six-cylinder engine
but have approximately the size, weight and cost of a four cylinder.)
However, one of the most amazing features of the Scuderi Engine is that
it really is two systems in one - an air compressor on one side and a
combustion engine on the other. By having fuel only enter the engine at
the power cylinder through direct cylinder injection, the compression
cylinder is pumping only air. This makes the Scuderi Engine the ideal
engine for an air-hybrid system. This feature of the engine has only
recently been patented and is expected to have a huge impact on the market.
By simply adding a storage tank and some controls, the engine would have
the ability to store energy normally lost during braking. (Similar to
the current electric hybrids) The big difference is that the Scuderi
Air-Hybrid only requires one system, not two. Since the Scuderi Engine
already uses compressed air in its combustion process, it can utilize
the energy stored in the tank without modifying how it operates. The
gains in efficiency come from eliminating the need for a compression
cycle. When the engine is operating out of the storage tank that has
been pressurized from the braking of the vehicle, the efficiency of the
engine can potentially run over 80%. Gains in mileage are much better
than an electric hybrid and there is no compromise to power and
performance. However, the biggest benefit however is the cost. To
convert the Scuderi Engine to an air-hybrid, the cost is a few hundred
dollars unlike an electric hybrid which adds thousands of dollars to the
cost of the vehicle.
A ready supply of compressed air has additional benefits. Engine
accessories and components can now easily be pneumatic - camless valve
design for example. As long as the engine is running, there is a source
of compressed air. External accessories can be operated such as air
tools or other devices. This has major significance, especially in
These are only some of the features of the Scuderi Engine. Two
proof-of-concept prototypes are currently being developed at the
renowned Southwest Research Institute (www.swri.org) in San Antonio,
Texas. We expect the first to be finished in early 2007.
I hope I was able to clarify some of the basics of the engine. Updated
materials on the Scuderi Engine and its air-hybrid design will be
available in the near future. This material will go into greater detail
on the specifics of the technology.
Sal Scuderi, President
The Scuderi Group
--- end quote ---
The animation does more to explain it to the layman than anything else
But... The animation doubles the number of cylinders needed...
Or... If 16:1 is the optimum fuel air ratio......
Then how do you take a burned 16:1 exhaust ratio, and use it as the intake
charge, no matter the inlet psi?
Jeff (Without asking Nate <lol>) Rice...
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