| 摘要 |
A manifold 24 has branches 22 leading from individual exhaust ports 20 engine to a downpipe 26 and a manifold 34 has branches 32 interconnecting the exhaust ports. The cross-sectional area of each branch 32 facing the exhaust flow from the associated exhaust valve is no less than 25% of the total port area and the branches of both manifolds 24, 34 terminate within the ports 20 in close proximity to the exhaust valves 18. In this way, a large proportion of the exhaust flow discharged from the exhaust valve of one cylinder is captured by the associated branch 32 of the manifold 34 and distributed by this manifold to the exhaust ports 20 of adjacent cylinders where the exhaust valves 18 are closed and leave the exhaust ports of the adjacent cylinders through the associated branches 22 of the manifold 24, scouring the closed ends of the exhaust ports in the process. A flat partition wall (30, Fig. 2) may divide each exhaust port 20 to direct exhaust flow to the manifolds 24, 34. A valve 52 controls the proportion of gases recirculated through the manifold 34 and may form the waste gate of a turbocharger 28. An exhaust gas oxygen sensor may be located in the manifold 34. <IMAGE> |
