Abstract: This heat engine, uses a Stirling cycle design, wherein a cold exchanger section of a cylinder and a hot exchanger section of the same cylinder are attached to an axis in an off-center positioned. The axis is preferably capable of rotation, but in some embodiments may be fixed. When a rotatable axis is used, a liquid acting as a piston moves within a portion of the cylinder against centrifugal force, and is driven by a working gas which is used in the same cylinder. By oscillating the liquid in the cylinder outwardly in the cylinder during a downward, or "power", stroke and inwardly in the cylinder during an upward, or "drag", stroke the center of mass of the liquid in the cylinder provides a greater moment of force during the downward power stroke than during the upward drag stroke. When used with a rotating axis and subjected to heating at a hot exchanger section and to cooling at a cold exchanger section at selected times it produces continuous power producing rotary motion about the axis.