Exhaust valve deactivation and intake valve phasing to enable deceleration fuel shut off and engine braking

A method of operating a four-cycle internal combustion engine having at least one combustion chamber with a reciprocating piston with cam driven intake and exhaust poppet valves, said piston having a top dead center position and a bottom dead center position, said method including selective deactivation of at least one of said combustion chamber during a desired deceleration event of said vehicle said engine is powering, said method including:

• disabling said cam driven exhaust poppet valve for said deactivated combustion chamber;
• and
• varying a phase of operation of said cam driving said deactivated combustion chamber intake poppet valve opening and closing to be generally symmetrical about one of said piston center positions.

An arrangement of an automotive vehicle comprising a four-cycle internal combustion engine, said engine including:

• an engine controller cognizant of a desired deceleration condition for said vehicle;
• and
• at least a first combustion chamber with a reciprocating piston mounted therein, said piston having a top dead center and a bottom dead center position, said first combustion chamber having a cam driven exhaust poppet valve which can be selectively disabled to a closed position to deactivate said first combustion chamber in response to a signal given by said engine controller, said first combustion chamber also having a variable phase cam driven intake poppet valve responsive to a signal given by said engine controller to selectively set the opening and closing operation of said intake poppet valve to be generally symmetrically about one of said center positions during said first combustion chamber deactivation during said vehicle deceleration.