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Scuderi Split Cycle Engine
The Scuderi Split Cycle Engine design is a rethink of the conventional
four-stroke Otto cycle internal combustion engine conceived by Carmelo
J. Scuderi (1925-2002). While as of this writing no working prototype
of the engine exists, computer simulations carried out by the Scuderi
Group and the Southwest Research Institute showed promising gains in
efficiency and toxic emissions. It also has the innate capacity to
power an air hybrid system.
n a conventional Otto-cycle engine, each cylinder
performs four strokes per cycle: intake, compression, power, and
exhaust. This means that two revolutions of the crankshaft are
required for each power stroke. The Scuderi split-cycle engine divides
these four strokes between two paired cylinders: one for
intake/compression and another for power/exhaust. Compressed air is
transfered from the compression cylinder to the power cylinder through
a crossover passage. Fuel is then injected and fired to produce the
power stroke. Because the engine produces one power stroke per
crankshaft rotation, a Scuderi-cycle engine has the same total engine
size (number of cylinders and displacement) as a comparable Otto-cycle
engine.
The power cylinder fires just after the piston has
begun its downward motion (after top dead center, or ATC). This is in
contrast to engine design convention, which calls for combustion just
before top dead center (BTC) in order to allow combustion pressure to
build. The Scuderi-cycle engine can get away with firing ATC because
its burn rate is faster, and so is able to build pressure more
quickly. This property of firing ATC is a key feature of the design,
as it enables the engine's higher efficiency and lower emissions
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