Marine engines and exhaust systems for marine engines

A marine engine comprising:

• a cylinder block having first and second banks of cylinders that are disposed along a longitudinal axis and extend transversely with respect to each other in a V-shape so as to define a valley;
• a conduit that conveys the exhaust gas from the marine engine, wherein the conduit reverses direction only once with respect to the longitudinal axis;
• wherein the conduit comprises a first branch conduit receiving exhaust gas from the first bank of cylinders, a second branch conduit receiving the exhaust gas from the second bank of cylinders and a third branch conduit receiving the exhaust gas from the first and second branch conduits and discharging the exhaust gas;
• a sealing interface between the third branch conduit and the first and second branch conduits.

A marine engine comprising:

• a cylinder block having first and second banks of cylinders that are disposed along a longitudinal axis and extend transversely with respect to each other in a V-shape;
• and
• a conduit that conveys the exhaust gas from the marine engine, wherein the conduit receives the exhaust gas from the first and second banks of cylinders and conveys the exhaust gas to an outlet, wherein the conduit reverses direction only once with respect to the longitudinal axis;
• wherein the conduit further comprises a first branch conduit receiving exhaust gas from the first bank of cylinders, a second branch conduit receiving the exhaust gas from the second bank of cylinders and a third branch conduit receiving the exhaust gas from the first and second branch conduits and discharging the exhaust gas to the catalyst receptacle;
• wherein the third branch conduit comprises a first conduit portion receiving exhaust gas from the first branch conduit, a second conduit portion receiving the exhaust gas from the second branch conduit, and a third conduit portion receiving the exhaust gas from the first and second conduit portions, and wherein the first and second conduit portions are separated by a dividing baffle.

A marine engine comprising:

• a cylinder block having first and second banks of cylinders that are disposed along a longitudinal axis and extend transversely with respect to each other in a V-shape;
• a conduit that conveys the exhaust gas from the marine engine, wherein the conduit receives the exhaust gas from the first and second bank of cylinders, and conveys the exhaust gas to an outlet;
• wherein the conduit reverses direction only once with respect to the longitudinal axis;
• wherein the conduit further comprises a first branch conduit receiving the exhaust gas from the first bank of cylinders, a second branch conduit receiving the exhaust gas from the second bank of cylinders, and a third branch conduit receiving the exhaust gas from the first and second branch conduits and discharging the exhaust gas;
• and
• wherein the conduit merges the exhaust gas from the first and second branch conduits together within a 180-degree bend.

A marine engine comprising:

• a cylinder block having first and second banks of cylinders that are disposed along a longitudinal axis and extend transversely with respect to each other in a V-shape to define a valley therebetween;
• and
• a conduit at least partially disposed in the valley, the conduit conveying the exhaust gas from the marine engine, the conduit reversing direction only once with respect to the longitudinal axis;
• wherein the conduit further comprises a first branch conduit receiving exhaust gas from the first bank of cylinders, a second branch conduit receiving the exhaust gas from the second bank of cylinders, the second branch conduit being separate from the first branch conduit, and a third branch conduit receiving the exhaust gas from the first and second branch conduits and discharging the exhaust gas;
• and
• wherein the third branch conduit comprises a first conduit portion receiving exhaust gas from the first branch conduit, a second conduit portion receiving the exhaust gas from the second branch conduit, and a third conduit portion merging the exhaust gas from the first and second conduit portions, and wherein the first and second conduit portions are separated by a dividing baffle.