Cylinder head, Valve guide, checking for wear

Insert a new valve into the guide so that  the stem is flush with the end of the valve guide.

Use a dial gauge against the side of the valve head, maximum permissible tilt is 0.65mm (0.025") on intake valves and 0.80mm (0.031") on exhaust valves.

Replace valve or guide if any measurement is below minimum specification.

Angle C is 45° on both intake and exhaust valves
Intake valves:  B = 0.50mm  (0.020")   D = 37mm (1.457")    E =36.6mm (1.441")  F = 1.2mm (0.047")
Exhaust valves :  B = 0.95mm (0.037")  D = 32mm (1.260")  E = 31.4mm (1.236") F =1.4mm (0.055")

Check valve seat for correct angles shown above. If out of specification , seats must be machined.

E30 M3 Repair Manual V2.7.  Copyright ©1999-2001 Koala Motorsport & Brett Anderson