Improved internal combustion engine and working cycle

The present invention relates to a method of operating an internal combustion engine including at least one cylinder and a piston slidable in the cylinder, the method comprising the steps of: supplying pressurized air from an intake manifold to an air intake port of a chamber in the cylinder; selectively operating an air intake valve to open the air intake port to allow pressurized air to flow between the chamber and the intake manifold substantially during a majority portion of a compression stroke of the piston; and operably controlling a fuel supply system to inject fuel into the chamber after the intake valve is closed.