1999 AUDI A4 AFC Engine Lock Carrier Removing For Service Workshop Manual

15-31

Valve seats, refacing


Note:

Pay attention to the cylinder head minimum
dimension when refacing valve seats page 15
-32


Only reface valve seats enough to produce
perfect contact.
Before refacing, calculate the maximum
permissible refacing dimension. If this
dimension is exceeded, correct functioning of
hydraulic valve lifters can no longer be
guaranteed and the cylinder head must be
replaced.

Intake valve seat
a - Diameter: 39.2 mm (1.543 in.)
b - Max. permissible refacing dimension
1)
c - Seat width: 2.0 mm (0.079 in.)
30 - Upper correction angle 45 - Valve seat angleZ - Bottom surface of cylinder head
Pa
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11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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pair&id=AUDI.B5.GE01.15.4

1) Calculating max. permissible refacing dimensions page 15
-32

Pa
ge 34 of 35 Lock carrier, removin
g for service
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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15-32


Exhaust valve seat 1) Calculating max. permissible refacing dimensions page 15
-32

Maximum permissible refacing dimension, calculating a - Diameter: 32.4 mm (1.276 in.)
b - Max. permissible refacing dimension
1)
c - Seat width: 2.4 mm (0.094 in.)
30 - Upper correction angle 45 - Valve seat angleZ - Bottom surface of cylinder head- Insert valve into guide and press firmly against valve seat.

The maximum permissible refacing dimension is the difference between
the actual distance measured at the cylinder head and the specified
minimum dimension.
Minimum dimensions - Measure distance -a- between end of valve stem and top surface of
cylinder head.
At intake valve: 33.8 mm (1.331 in.)At exhaust valve: 34.1 mm (1.343 in.)
Pa
ge 35 of 35 Lock carrier, removin
g for service
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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e=re
pair&id=AUDI.B5.GE01.15.4