Exhaust structure for exhaust manifold

An exhaust manifold for an engine, the exhaust manifold comprising:

• an exhaust structure including:
• a first inlet section arranged at a first side of the exhaust structure, wherein the first inlet section defines a first inlet flow passage in fluid communication with a first set of cylinders of the engine to receive exhaust gas therefrom, the first inlet flow passage having a diameter defining a normalized cross-sectional area of flow;
• a second inlet section arranged at a second side of the exhaust structure, wherein the second inlet section defines a second inlet flow passage in fluid communication with a second set of cylinders of the engine to receive exhaust gas therefrom, the second inlet flow passage having the diameter defining the normalized cross-sectional area of flow;
• and
• an intermediate section disposed between the first inlet section and the second inlet section and in fluid communication with each of the first inlet section and the second inlet section, the intermediate section including:
• a flange;
• an outlet section defining an outlet flow passage extending through the flange that is in fluid communication with each of the first inlet flow passage and the second inlet flow passage, the outlet flow passage including a single opening through the flange through which exhaust gas from both the first inlet section and the second inlet section exits the exhaust structure;
• and
• an exhaust redirection section disposed between the first inlet section and the second inlet section, the exhaust redirection section defining a redirection flow passage adjacent the outlet section, the redirection flow passage defining a redirection cross-sectional area of flow, the redirection cross-sectional area of flow, measured at a midpoint of the flange, being less than the normalized cross-sectional area of flow of the first inlet flow passage;
• and
• a manifold portion secured to the exhaust structure at the second side of the exhaust structure, wherein the manifold portion is arranged to receive exhaust gas from at least one cylinder of the second set of cylinders.

An exhaust structure for an exhaust manifold, the exhaust structure comprising:

• a first inlet section that defines a first inlet flow passage;
• a second inlet section that defines a second inlet flow passage;
• and
• an intermediate section disposed between the first inlet section and the second inlet section and in fluid communication with each of the first inlet section and the second inlet section, the intermediate section including:
• a flange;
• an outlet section defining an outlet flow passage extending through the flange, the outlet flow passage being in fluid communication with each of the first inlet flow passage and the second inlet flow passage and including an outlet opening through the flange;
• and
• an exhaust redirection section disposed between the first inlet section and the second inlet section such that exhaust from the first inlet section and from the second inlet section is configured to converge at the exhaust redirection section, the exhaust redirection section having areas of curvature configured to guide exhaust towards the outlet opening, including areas of curvature that define a ridge at a central portion of the exhaust redirection section.