Patent ID: 6962049

Claim:
An engine comprising: four cylinders; an exhaust manifold mounted to a cylinder head of the engine; and four exhaust manifold branches included in the exhaust manifold and arranged to each cylinder, wherein two exhaust manifold branches of two cylinders that are not fired in succession are convergent at a convergence angle equal to or below 20 degrees to form a first convergent exhaust manifold branch, two exhaust manifold branches of another two cylinders that are not fired in succession are convergent at a convergence angle equal to or below 20 degrees to form a second convergent exhaust manifold branch, and the first convergent exhaust manifold branch and the second convergent exhaust manifold branch are thereafter made convergent, wherein the four cylinders line up in order of cylinder # 1 , cylinder # 2 , cylinder # 3 , and cylinder # 4 , the four cylinders being fired in order of cylinder # 1 , cylinder # 3 , cylinder # 4 , and cylinder # 2 , wherein the two exhaust manifold branches of the cylinder # 1 and the cylinder # 4 arranged at both ends in a cylinder-in-line direction of the engine are convergent, and the two exhaust manifold branches of the cylinder # 2 and the cylinder # 3 arranged between the cylinder # 1 and the cylinder # 4 in the cylinder-in-line direction of the engine are convergent, and wherein the second convergent exhaust manifold branch is formed such that the two exhaust manifold branches of the cylinder # 2 and the cylinder # 3 are projected toward each other and substantially along the cylinder-in-line direction, and are thereafter convergent.