Abstract: A system of generating power in a multi-cylinder internal combustion engine. Each cylinder has a reciprocating piston passing in sequence through an intake stroke, a compression stroke, a power stroke and an exhaust stroke. A charge is drawn from an intake manifold through an intake valve and into a cylinder during the intake stroke. Greater than half of a volume of the cylinder is displaced, thereby returning a substantial portion of the charge to the intake manifold through the intake valve during the compression stroke at all operating speeds. The remaining charge in the cylinder is compressed during the compression stroke after closing the intake valve. The charge is ignited to expand the charge and liberate energy during the power stroke. The cylinder is exhausted of burned charge during the exhaust stroke. The quantitative expansion of the charge during the power stroke is at least twice the quantitative compression of the charge during the compression stroke.