Abstract: A reciprocating piston-type internal combustion engine is equipped with a variable length connecting rod which is operable in response to engine oil pump pressures to cause a low throttle fuel charge to be compressed in the engine cylinder to substantially the same pressure as an open throttle fuel charge. An adjustable pressure regulator valve is provided to insure a substantially constant oil pressure at the connecting rod at all times during operation of the engine.

Abstract: An internal combustion engine has an articulated connecting rod linkage which is automatically adjusted by an improved fluid-pressure-responsive control, so that different density fuel-air charges inducted into the engine cylinder will be compressed to substantially the same extent each time the cylinder is fired, regardless of throttle setting, engine speeds, or loads.

Abstract: An internal combustion engine has a crankshaft offset to one side of the axis of the engine cylinder and an articulated connecting rod linkage operable to vary the stroke of the engine piston in accordance with engine operating conditions, so that different density fuel-air charges inducted into the cylinder will be compressed to substantially the same extent each time the cylinder is fired, regardless of throttle setting, engine speeds, or loads.

Abstract: A connecting rod whose length varies according to given pressure changes in the cylinder of an associated internal combustion engine. The connecting rod lengthens in response to subatmospheric pressures acting on the piston during the fuel intake stroke, and shortens in response to superatmospheric pressures of a given magnitude acting on the piston.