Dual Mode Internal Combustion Engine

A reciprocating, internal combustion engine is capable of two modes of operation. The engine comprises three cylinders of substantially equal diameter. Each cylinder is provided with a piston. During operation, all pistons are synchronized and move in phase with one another. Valves are configured to selectively close paths between the second cylinder and two combustion chambers. Further valves are provided to selectively seal intake and exhaust channels leading to the two combustion chambers. A high efficiency combustion mode is achieved by increasing an expansion ratio through intake and compression of the fuel mixture in one cylinder and expansion in two cylinders. A high power combustion mode is achieved by compression and intake of the fuel mixture in two cylinders and expansion in one cylinder.