Patent ID: 7962276

Claim:
An internal combustion engine comprising: a plurality of combustion chambers; an air induction system for delivering air to each combustion chamber; a fuel system for delivering fuel to each combustion chamber; an exhaust system for relaying combusted gases form the combustion chambers to atmosphere; and an exhaust recirculation system to relay combusted gases from the exhaust system to at least one of the combustion chambers; wherein: the engine has a chamber deactivation operating mode in which at least one combustion chamber is active and receives fuel and air which are combusted therein and at least one other combustion chamber is deactivated and is supplied with no fuel by the fuel system; in the said chamber deactivation operating mode the exhaust gas recirculation system supplies combusted gas to the (or each) deactivated combustion chamber; a plurality of inlet poppet valves are provided to control flow of air to the combustion chamber(s), the inlet poppet valves being operated by a rotatable camshaft having for each inlet poppet valve a first inlet cam and a second inlet cam with a different profile to the first inlet cam with tappet means being provided for each inlet poppet valve to transmit lift to the inlet poppet valve selectively from the first inlet cam or the second inlet cam; in a first operating condition of the engine in which every combustion chamber is active and each inlet poppet valve is driven by the respective first inlet cam therefor; and in a second operating condition of the engine the engine operates in the valve deactivation mode with at least one combustion chamber deactivated and each inlet valve for each active combustion chamber is driven by the respective first inlet cam therefor whereby each active combustion chamber operates a Miller cycle combustion cycle by each first inlet cam for each active combustion chamber closing each inlet poppet valve early to reduce each inlet stroke in each active combustion chamber.