Chapter 3 Ventilation system Section 1 Valve train p (a) The fourth cylinder The second cylinde first cylinder The third cylinder exhaust intake intake exhaust exhaust intakeintake exhaust ®迪®电®④ 0H此0e0阳0p (b】 (c) Figure 3.11 four-cylinder four-stroke gasoline engine camshaft (a )492QA engine camshaft b)relative angle position of cams diagram (c)air intake or exhaust cam projection 械电子工程学度 Automobile and Tractor Northwest A&F University Automobile and Tractor Northwest A&F University Chapter 3 Ventilation system Figure 3.11 four-cylinder four-stroke gasoline engine camshaft （a）492QA engine camshaft （b） relative angle position of cams diagram （c） air intake（ or exhaust ）cam projection Section 1 Valve train