The angle values are determined by turning the driving shaft clockwise.
S = Piston at top dead centre
I = Piston at bottom dead centre
α = Intake valve open
β = Intake valve closed
γ = Exhaust valve open
δ = Exhaust valve closed
Timing angles for operating purposes (valve clearance = 0.25 mm)
α = 16° before S
β = 36° after I
γ = 36° before I
δ = 16° after S
Timing angles for checking puposes (valve clearance = 2 mm)
α = 21° after S
β = closes in I
γ = 2° after I
δ = 20° before S
