Chapter 1 Basic structure and principle of the engine Section 2 Basic working principle 2.1 Four-stroke gasoline engine working principle inlet inlet intake stroke port fuel/air mixture mixture. intake Atmospheric pressure line connecting rod crankshaft otation (a) 业机电子工程学度 Automobile and Tractor Northwest A&F University Automobile and Tractor Northwest A&F University Chapter 1 Basic structure and principle of the engine 2.1 Four-stroke gasoline engine working principle intake stroke Section 2 Basic working principle