Cutters for machining valve seats
B — valve contact width;
F — valve guide bushing;
H — height of the cylindrical part;
S — valve seat ring.
The valves are ground on a grinding machine at an angle of 45°. Valves with too small a height (H) must be replaced. Minimum edge thickness for petrol engines: exhaust valve - H=1.98 mm, intake valve - H=1.19 mm.

Note: When machining the valve seat, machine the surface at an angle of 45°, then machine the width of the contact surface by milling while maintaining the correction angle. After machining, grind the valves.
Dimensions after machining of valve seats
Examine the original source using the link on the website «BMWman.ru»
