Fluid-cooled manifolds and engine systems

A method of cooling exhaust from an engine, the method comprising:

• operating an engine so as to produce exhaust;
• directing at least a portion of the exhaust from the engine into a first fluid-cooled manifold that is coupled to the engine, wherein the first fluid-cooled manifold comprises:
• a first group of exhaust runners including a first exhaust runner and a second exhaust runner, wherein the first exhaust runner is detached from the second exhaust runner, and wherein each exhaust runner of the first group of exhaust runners comprising:
• a runner body having an inlet end and an outlet end,
• an exhaust conduit extending through the runner body from an exhaust inlet opening at the inlet end of the runner body to an exhaust outlet opening at the outlet end of the runner body, and
• a coolant passage extending through the runner body from a coolant inlet opening to a coolant outlet opening;
• directing a coolant from a coolant feed pipe into the coolant passage of each exhaust runner of the first group of exhaust runners, wherein the coolant feed pipe includes a plurality of outlets and each outlet is coupled to the coolant inlet of a respective one of the exhaust runners of the first group of exhaust runners;
• and
• receiving, in a coolant exit pipe, the coolant from the coolant passage of each exhaust runner of the first group of exhaust runners, wherein the coolant exit pipe includes a plurality of inlets, and wherein each inlet of the coolant exit pipe is coupled to the coolant outlet of a respective one of the exhaust runners of the first group of exhaust runners.