Marine engines and exhaust systems for marine engines having a catalyst for treating exhaust

A marine engine comprising:

• a cylinder block having first and second banks of cylinders that are disposed along it longitudinal axis and extend transversely with respect to each other in a V-shape so as to define a valley there between;
• a catalyst receptacle that is disposed at least partially in the valley and contains at least one catalyst that treats exhaust gas from the marine engine;
• and
• a conduit that conveys the exhaust gas from the marine engine to the catalyst receptacle, wherein the conduit receives the exhaust gas from the first and second banks of cylinders and conveys the exhaust gas to the catalyst receptacle, wherein the conduit reverses direction only once with respect to the longitudinal axis;
• wherein a portion of the conduit extends out from a top end of the valley and then hack into the top end with respect to the longitudinal axis.

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 there between;
• a catalyst receptacle that is disposed at least partially in the valley and contains at least one catalyst that treats exhaust gas from the marine engine;
• and
• a conduit that conveys the exhaust gas from the marine engine to the catalyst receptacle, wherein the conduit receives the exhaust gas from the first and second banks of cylinders and conveys the exhaust gas to the catalyst receptacle, 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 hank 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;
• 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 so as to define a valley there between;
• a catalyst receptacle that is disposed at least partially in the valley and contains at least one catalyst that treats exhaust gas from the marine engine;
• and
• a conduit that conveys the exhaust gas from the marine engine to the catalyst receptacle, wherein the conduit receives the exhaust gas from the first and second banks of cylinders and conveys the exhaust gas to the catalyst receptacle, 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 so as to define a valley there between;
• a catalyst receptacle that is disposed at least partially in the valley and contains at least one catalyst that treats exhaust from the marine engine;
• and
• a conduit that conveys the exhaust gas from the marine engine to the catalyst receptacle, wherein the conduit receives the exhaust gas from the first and second bank of cylinders, and conveys the exhaust gas to the catalyst receptacle;
• 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 to the catalyst receptacle;
• 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 comprises a single 180-degree bend that conveys the exhaust gas from a vertically upward directional flow to a vertically downward directional flow with respect to the longitudinal axis;
• wherein the valley has a center located proximate to the cylinder block and wherein the 180-degree bend carries the exhaust gas radially outwardly away from the center of the valley;
• 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.