Chapter 3 Ventilation system Section 1 Valve train (1)Valve (a) (b) (e) Figure 3.4 Valve head construction type Figure 3.5 Valve cone angle (a)flat heads (b)horn heads 机被寿电子工程原二 Automobile and Tractor Northwest A&F UniversityAutomobile and Tractor Northwest A&F University Chapter 3 Ventilation system (1) Valve Figure 3.4 Valve head construction type (a) flat heads (b) horn heads Figure 3.5 Valve cone angle Section 1 Valve train