Porsche 928 Workshop Manual page 180

15
Engine/Cylinder Head, Valves
928
Removing and installing Valve
Springs
Remove and install valve springs with P 200 a.
Remove and install valve springs with US 1020
(only applicable for USA).
Checking Installed Length of
Valve Springs
1. Install Special Tool 9138 with shims belonging
to a pertinent valve. spring retainer and both
keepers.
2. Read distance from Special Tool 9138 and, if
necessary, correct by adding or removing shims.
Shims are available in thicknesses of 0.5 and
1.0 mm.
928 Models 197811979
Intake valve 39.6 + 0.5 mm
Exhaust valve
36.6 + 0.5 mm
928 Models 1980
Intake valve 38.2 t 0.3 mm
Exhaust valve 38.2 + 0.3 mm
928 S
Intake valve 38.5 + 0.5 mm
Exhaust valve 37.5 + 0.5 mm
Example: 928 Models 1980
Special Tool 9136 shows 38.6 mm. In this case
install one more 0.5 mm shim.
Example: 928 S (Exhaust Valvel
Special Tool 9138 shows 38.6 mm. In this case
install additional 1 .O mm shims.
a
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15.8b Disassembling and Assembling Valve Drive v11,19!33
Printed in Germany