Exhaust scavenging system

An exhaust scavenging system for an internal combustion engine, comprising

• at least three exhaust passages extending from the engine, each including an outlet, the outlets being equidistant from a common center line and terminating substantially in an outlet plane, the exhaust passage outlets defining a center space thereamong;
• an exhaust outlet system including a singular tube;
• a collector having an inlet collector portion configured to interface with and extend about the exhaust passages at the outlet plane in sealed arrangement, an outlet collector portion configured to interface with the singular tube of the exhaust outlet system and a transition collector portion between and providing flow transition between the inlet and outlet collector portions;
• a flow enhancement element in sealed arrangement with the exhaust passages at the outlet plane to close the center space and extending solely from the center space into the transition collector portion, the flow enhancement element being slidable relative to the outlet plane between an extended position and a retracted position;
• and
• an actuator coupled with the flow enhancement element and responsive to at least one engine parameter to move the flow enhancement element toward the extended and retracted positions based on a function of the at least one engine parameter.

An exhaust scavenging system for an internal combustion engine, comprising

• at least three exhaust passages extending from the engine, each including an outlet, the outlets being equidistant from a common center line and terminating substantially in an outlet plane, the exhaust passage outlets defining a center space thereamong;
• an exhaust outlet system including a singular tube;
• a collector having an inlet collector portion configured to interface with and extend about the exhaust passages at the outlet plane in sealed arrangement, an outlet collector portion configured to interface with the singular tube of the exhaust outlet system and a transition collector portion between and providing flow transition between the inlet and outlet collector portions;
• a flow enhancement element in sealed arrangement with the exhaust passages at the outlet plane to close the center space and extending along the common center line into the transition collector portion, the flow enhancement element being slidable relative to the outlet plane between an extended position and a retracted position, the transverse cross-sectional area of the flow enhancement element through at least half of the transition collector portion from the outlet plane not being substantially less than the transverse cross-sectional area of the flow enhancement element at the outlet plane in the extended position and decreasing continuously through the transition collector portion from the outlet plane in the retracted position;
• and
• an actuator coupled with the flow enhancement element and responsive to at least one engine parameter to move the flow enhancement element toward the extended and retracted positions based on a function of the at least one engine parameter.

An exhaust scavenging system for an internal combustion engine, comprising

• at least three exhaust passages extending from the engine, each including an outlet, the outlets being equidistant from a common center line and terminating substantially in an outlet plane, the exhaust passage outlets defining a center space thereamong;
• an exhaust outlet system including a singular tube;
• a collector having an inlet collector portion configured to interface with and extend about the exhaust passages at the outlet plane in sealed arrangement, an outlet collector portion configured to interface with the singular tube of the exhaust outlet system and a transition collector portion between and providing flow transition between the inlet and outlet collector portions;
• a flow enhancement element in sealed arrangement with the exhaust passages at the outlet plane to close the center space and extending solely from the center space into the transition collector portion with lateral flow communication between adjacent ones of the exhaust passages at the outlet plane, the flow enhancement element being slidable relative to the outlet plane between an extended position and a retracted position;
• and
• an actuator coupled with the flow enhancement element and responsive to at least one engine parameter to move the flow enhancement element toward the extended and retracted positions based on a function of the at least one engine parameter.