Split-cycle engine
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The Scuderi Split Cycle Engine is a design of internal combustion engine invented by Carmelo J. Scuderi. The Scuderi group who own the patents on the design, claim that computer simulations of the engine show promising gains in efficiency and reduced toxic emissions over conventional four-stroke Otto cycle designs. The group also claim it could be used as part of an air hybrid system.
As of April 2007 no working prototypes of the engine exist.
Design
In 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 transferred from the compression cylinder to the power cylinder through a crossover passage. Fuel is then injected and fired to produce the power stroke. In a standard Otto cycle engine, the pistons fire every other revolution. However, the Scuderi engine fires every revolution.
In the Scuderi cycle, the power cylinder fires just after the piston has begun its downward motion (after top dead center, or ATDC). This is in contrast to Otto cycle design convention, which calls for combustion just before top dead center (BTDC) in order to allow combustion pressure to build.