发动机生产厂设计进、排气管时,均用科学方法设计进、排气管长度及弯曲半径。要求进气管道具有尽可能大的尺寸而且拐弯要少,气道内表面要光滑;要求排气管排气阻力要小,结构要简单。但是,现在有不少机手自己改装排气管,特别是搞运输作业的机手,他们为了避免排气烟雾熏眼,改成如图所示的形状。这样,使得排气管 Engine design into the exhaust pipe, are used scientific methods into the exhaust pipe length and bending radius. Requires the intake pipe with the largest possible size and less turning, the inner surface of the airway to be smooth; require exhaust pipe exhaust resistance is small, the structure should be simple. However, quite a few handlers have converted their own exhaust pipes themselves, especially for transport operations. In order to avoid the smoky exhaust of smoke and smoke, they have been transformed into the shape shown in the figure. This makes the exhaust pipe