Engine

1 . An engine that is a V-type engine comprising a first bank and a second bank arranged side by side in a left-right direction, the engine comprising:

a first cooling liquid passage and a second cooling liquid passage disposed between the first bank and the second bank and extending in a front-rear direction; and

an exhaust manifold passage disposed inside a space formed between the first bank and the second bank and extending in the front-rear direction and disposed below the first cooling liquid passage and the second cooling liquid passage, passage, wherein

the first bank, the first cooling liquid passage, the exhaust manifold passage, the second cooling liquid passage, and the second bank are arranged in the stated order from one side to another side in the left-right direction,

at least one of the first cooling liquid passage and the second cooling liquid passage includes a first wall portion extending downwards; and

the cooling liquid passage including the first wall portion includes a second wall portion extending from a lower end portion of the first wall portion toward a closer one of the first bank and the second bank.

2 . An engine that is a V-type engine comprising a first bank and a second bank arranged side by side in a left-right direction, the engine comprising:

a first cooling liquid passage and a second cooling liquid passage disposed between the first bank and the second bank and extending in a front-rear direction,

an exhaust manifold passage disposed between the first bank and the second bank and extending in the front-rear direction and disposed below the first cooling liquid passage and the second cooling liquid passage, wherein

the first bank, the first cooling liquid passage, the exhaust manifold passage, the second cooling liquid passage, and the second bank are arranged in the stated order from one side to another side in the left-right direction,

at least one of the first cooling liquid passage and the second cooling liquid passage includes a first wall portion extending downwards; and

the cooling liquid passage including the first wall portion includes a second wall portion extending from a lower end portion of the first wall portion toward a closer one of the first bank and the second bank.

3 . An engine that is a V-type engine comprising a first bank and a second bank arranged side by side in a left-right direction, the engine comprising:

a first cooling liquid passage and a second cooling liquid passage disposed between the first bank and the second bank and extending in a front-rear direction; and

an exhaust manifold passage disposed between the first bank and the second bank and extending in the front-rear direction and disposed below the first cooling liquid passage and the second cooling liquid passage, wherein

the exhaust manifold passage includes a first exhaust passage section and a second exhaust passage section arranged side by side in the left-right direction,

the first exhaust passage section and the second exhaust passage section are formed by connecting a plurality of portions of the exhaust manifold passage by corresponding connecting portions, and

the first exhaust passage section and the second exhaust passage section are disposed with a position of the corresponding connecting portion of the first exhaust passage section and a position of the corresponding connecting portion of the second exhaust passage section being offset in the front-rear direction.

4 . The engine according to claim 1 , further comprising

an intake filter disposed above the first cooling liquid passage,

wherein the intake filter either overlaps the first cooling liquid passage in a plan view from above, or is disposed on an opposite side of the exhaust manifold passage with the first cooling liquid passage interposed therebetween.

5 . The engine according to claim 1 , further comprising

a blow-by gas passage disposed above the first cooling liquid passage,

wherein at least a part of the blow-by gas passage either overlaps the first cooling liquid passage in a plan view from above, or is disposed on an opposite side of the exhaust manifold passage with the first cooling liquid passage interposed therebetween.

6 . The engine according to claim 1 , further comprising a cover member that covers at least a part of the first cooling liquid passage, the second cooling liquid passage, and the exhaust manifold passage.