| 摘要 |
An exhaust manifold with several inlet ports and a combination of diffuser and nozzle portions associated with each inlet port for producing a hig h flow rate and a low pressure drop from entry to exit. The diffuser and nozzle portions are in series and designed into the manifold at each inlet port and sli ghtly upstream of the next downstream positioned inlet port. The diffuser portion decreases the velocity of exhaust gases as they enter the manifold and are then turned substantially ninety degrees into a longitudinal direction of the manifol d. This diffuser action slows the velocity and reduces pressure losses as the turn of exhaust flow is accomplished. The next in series nozzle portion increases the velocity of exhaust gases to cause the flowstream to jump past a neighboring downstream engine exhaust port. Resultantly, the flow through the manifold is improved and the pressure drop decreased which enhances engine performance. Also, the heat rejection and thermal inertia of the manifold is decreased which enhances the earlier heating and light-off of a downstream catalyst of a gas treatment unit.
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