Valve seat machining (VW Polo 3)

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

2. Measure the distance between the end of the valve stem and the top edge of the cylinder head (Fig. 6.29).



3. Calculate the maximum allowable distance for lapping.

Minimum distance for inlet valve: 35.8 mm.
Minimum distance for exhaust valve: 36.1 mm.

4. Measured distance - minimum distance = maximum allowable distance for lapping. For example, measured distance 36.5 mm - minimum distance 35.8 mm = maximum allowable distance for lapping 0.7 mm.

Engines AEY, AFN, ANV, AHU, AKW, ALE

The seat angles of the inlet valve are shown in Fig. 6.30, and of the outlet valve - in Fig. 6.31.





Intake valve seat angles

• Diameter a: 35.7 mm.
• Diameter b: 1.6 mm.
• 45° - Valve seat angle.

Exhaust valve seat angles

• Diameter a: 31.4 mm.
• Diameter b: 2.7 mm.
• 45° - Valve seat angle.

Engine 1Y

The valve seat angles are shown in Fig. 6.32.

Valve seat angles