skoda Workshop Repair Guides

Skoda Workshop Service and Repair Manuals

ABOUT US
Inspect valve guides > < Repairing Valve Gear

Octavia Mk1

Grinding in valve seats
Grinding in valve seats
Special tools and workshop equipment required
t  Grinding paste
  Note
t  When carrying out repairs on engines with leaking valves, it is not sufficient to machine or replace the valve seats and valves. It is also necessary to inspect the valve guides for wear, particularly on engines with a high mileage → Chapter.
t  Rework valve seats only sufficiently in order to obtain a proper contact pattern. Calculate the maximum permissible reworking dimension before commencing → Anchor. If the reworking dimension is exceeded, the proper operation of the hydraulic valve clearance compensation is no longer ensured. If this is the case replace the cylinder head.
Calculating maximum permissible reworking dimension
–  Insert valve and press firmly against the valve seat.
  Note
If the valve is replaced when carrying out repair work, use a new valve for the measurement.
   
–  Measure distance -a- between the end of the valve stem and the upper face of the cylinder head.
–  Calculate max. permissible reworking dimension from the distance -a- measured and the minimum dimension.
Minimum dimension:
   Inlet valve 35.8 mm
   Outlet valve 36.1 mm
Distance measured -a- minus minimum dimension = max. permissible reworking dimension.
Example:
  S15-0312

-		distance measured -a-
Minimum dimension		36,5
35,8		mm
mm
=max. permissible reworking dimension0,7mm

  Note
If the max. permissible reworking dimension is 0 mm, repeat measurement with a new valve. If the max. permissible reworking dimension is again 0 mm, replace cylinder head.
   
Reworking inlet valve seat
a = 35.7 mm
b = 1.6 mm
45° = Valve seat angle
  Note
The 30° rear milled section on the valve seat is absoluteiy essential due to the flow characteristics in the inlet canal.
  S15-0304
Reworking exhaust valve seat
a = 31.4 mm
b = 2.7 mm
45° = valve seat angle
  S15-0305
–  Grind in valve/valve seat -arrows- with fine grinding paste until a perfect contact pattern is achieved.
–  Inspect valve for leaks.
The inspection can be carried out with water colour (perfect contact pattern over entire circumference) or by filling fuel into the interior of the cylinder head (no fuel must flow out at the valve seat).
  Note
After installing the cylinder head, check the hydraulic bucket tappets → Chapter.
  S15-0061

Inspect valve guides > < Repairing Valve Gear