SEAT Workshop Service and Repair Manuals

Calculate the max. permissible reworking dimension –  Insert valve and press firmly against valve seat.   Note If the valve is to be renewed as part of a repair, use a new valve for the calculation.

–  Measure distance between end of valve stem and upper edge of cylinder head. –  Calculate maximum permissible reworking dimension from measured distance and minimum dimension. Minimum dimensions: t  Inlet valve 7.6 mm t  Exhaust valve 7.6 mm Measured distance minus minimum dimension = max. permissible machining dimension. Example:

	Distance measured Minimum distance	8,0 7,6	mm mm
=	Max. permissible reworking dim. → Remark	0,4	mm

1)  The max. permissible reworking dimension is shown on illustrations for reworking valve seats as dimension „b“.

Reworking the intake valve seat

a	= Ø 28.7 mm
b	= Max. permissible reworking dim. → Remark
c	= 1.5...1.8 mm
Z	= cylinder head lower edge
α	= 45 ° angle
β	= 30 ° upper correction angle of valve seat
γ	= 60 ° lower correction angle

2)  Calculating max. permissible reworking dimension → Chapter

Reworking the exhaust valve seat

a	= Ø 25.0 mm
b	= Max. permissible reworking dim. → Remark
c	= approx. 1.8 mm
Z	= cylinder head lower edge
α	= 45 ° valve seating angle
β	= 30 ° upper correction angle
γ	= 60 ° lower correction angle

3)  Calculating max. permissible reworking dimension → Chapter