Contents Section: 6.0l 12-cyl. 4v Engine Mechanical, Engine Code(s): Bsb All sections

Determining maximum allowable reworking dimension Audi A8 D3 рестайлинг

Determining maximum allowable reworking dimension

  1. Insert valve and press it firmly against valve seat.

Note. If the valve is to be replaced as part of a repair, use a new valve for the calculation.

Scheme 558

Scheme 558
  1. Measure distance - a - between end of valve stem and upper cylinder head surface with a depth gauge.
  2. Calculate maximum allowable reworking dimension from measured distance and minimum dimension.
Minimum dimension
Short intake valveLong intake valveShort exhaust valveLong exhaust valve
32.2 mm10.6 mm32.2 mm10.6 mm

Measured distance minus minimum dimension = max. permissible reworking dimension.

Example for long intake valve
Measured distance10.8 mm
Minimum dimension10.4 mm
=Max. permissible reworking dimension= 0.4 mm

Note. If the maximum allowed reworking dimension is 0 mm or less than 0 mm, repeat the measurement using new valve. If the measurement result is still 0 mm or less than 0 mm, replace the cylinder head.

Scheme 559

Scheme 559: Reworking intake valve seat

a - diameter 32.6 mm

b - Max. permissible reworking dimension

c - 0.9 to 1.5 mm

d - max. diameter 35.0 mm

r2 - Radius 2.0 mm

Z - Cylinder head lower edge

α - 45 valve seat angle

β - 30 upper correction angle

gamma - 60 lower correction angle

Note. Calculating the maximum allowable reworking dimension, --> Determining maximum allowable reworking dimension .