Patent ID: 8550042

Claim:
A method for operating a two-stroke, uniflow, full expansion internal combustion (IC) engine, the method comprising repeating a cylinder cycle, the cycle comprising the steps of: a) passing pressurized inlet air through an uncovered swirl inlet port and into a cylinder with a piston proximate the bottom of its reciprocal stroke (BDC) within the cylinder, and swirling the inlet air in tangential turbulent unidirectional flow within the cylinder, b) maintaining an exhaust port in an open position while the swirl inlet port is uncovered to provide scavenging of the cylinder by the inlet air, c) advancing the piston upward to cover the swirl inlet port, d) further maintaining the exhaust port in an open position after covering the swirl inlet port for a substantial portion of the remaining stroke movement of the piston toward top dead center (TDC); e) closing the exhaust port, f) compressing the inlet air between the piston and the cylinder head toward top dead center, g) dispersing a fuel near the end of the compression stroke at a lean burning fuel to air ratio, h) igniting and combusting the air-fuel mixture to initiate the power stroke, i) opening the exhaust port near the end of the power stroke to exhaust pressurized combustion gases, and j) uncovering the swirl inlet port as the piston approaches the bottom of its power stroke; wherein the exhaust port is open for a majority of crank cycle between the BDC position to the TDC position.