An internal combustion engine combustion system, including an ignition element and an ignition actuation member. The ignition element is configured to ignite an air-fuel mixture compressed within a combustion chamber of an internal combustion engine. The ignition actuation member is movable between a first position in which the ignition actuation member prevents ignition of the air-fuel mixture when present in the combustion chamber, and a second position in which the ignition actuation member permits ignition of the air-fuel mixture by exposing the ignition element to the air-fuel mixture when the air-fuel mixture is present in the combustion chamber.