Valve Seats, Refacing Audi A8 D2

Note. Only reface valve seats enough to achieve a proper contact surface. Before refacing, calculate the maximum permissible refacing dimension. If refacing exceeds this dimension, proper operation of the hydraulic valve lifters can no longer be guaranteed and the cylinder head must be replaced.

Scheme 83

1. Insert valve into valve seat and press valve firmly against valve seat. see scheme 92: Measuring Distance Between End Of Valve Stem And Top Of Cylinder Head
2. Measure distance (arrow) between end of valve stem (center) and top of cylinder head. From this measured distance, subtract the specified minimum dimension to calculate maximum amount of material that can be removed when refacing the valve. See «MINIMUM DIMENSION»(ref-196861-S36501707762005100900000) table. MINIMUM DIMENSION Minimum dimension ABZ AEW Intake 36.0 mm (1.417 in.) 36.4 mm (1.433 in.) Exhaust 36.3 mm (1.429 in.) 36.4 mm (1.433 in.)

Identifying Intake Valve Seat Angles. Scheme 84

Refacing Intake Valve Seats Reference Data. Scheme 85

Identifying Exhaust Valve Seat Angles. Scheme 86

Refacing Exhaust Valve Seats Reference Data. Scheme 87