Split-cycle engine

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.