Method and system for turbocharging an engine

An engine method, comprising:

• opening a first exhaust valve of a cylinder before a piston reaches BDC expansion stroke of the cylinder;
• directing exhaust gases across the first exhaust valve into a first conduit;
• and
• recovering heat from the exhaust gases in the first conduit to a liquid, and then returning the cooled exhaust gases to a second conduit that is in communication with a second, later-opening, exhaust valve of the cylinder.

An engine system, comprising:

• a first cam profile in communication with a first exhaust valve in a first exhaust port of a cylinder;
• a second cam profile in communication with a second valve in a second exhaust port of the cylinder;
• a first exhaust conduit extending from the first exhaust port of the cylinder;
• a second exhaust conduit extending from the second exhaust port of the cylinder, the second exhaust port isolated from the first exhaust port;
• a gas-to-liquid heat exchanger located in a first branch of the first exhaust conduit, an outlet of the gas-to-liquid heat exchanger directed to an intake manifold and the second conduit;
• a turbocharger located in a second branch of the first exhaust conduit;
• and
• a first catalyst and a second catalyst located along the second conduit.

An engine method, comprising:

• opening and closing a first exhaust valve of a cylinder before a piston reaches BDC expansion stroke of the cylinder;
• directing gases across the first exhaust valve into a first conduit;
• and
• recovering heat from the gases in the first conduit to a liquid, and then returning the cooled gases to a second conduit that is in communication with a second, later-opening, exhaust valve of the cylinder.