Nanni T4.155 seriers, Workshop Manual

Page: 114 / 191

60300140 (
indice A
) 4 CYLINDERS WORKSHOP MANUAL 114/191
2. REINSTALL THE COMBUSTION CHAMBERS
a. Make the combustion chamber position pin coincide with the
corresponding recess in the cylinder head.
b. Use a plastic mallet to fit the combustion chambers and position
them.
c. Use a dial gauge to verify the amount the combustion chambers
protrude.
Combustion chamber protrusion:
Less 0.03 – plus 0.02 mm
If the protrusion of the combustion chamber is less than the specified
dimension, obtain this dimension with thickness shims.
Thickness shim thickness: 0.05 mm/0.10 mm
If the protrusion of the combustion chamber is less than the specified
dimension, replace the combustion chamber, then check the amount of
protrusion again.
3. REINSTALL VALVES
a. Reinstall the following parts:
1. Oil gasket
2. Valve
3. Spring
cup
4. Valve spring
5. Spring key
b. Compress the valve springs using special maintenance tool SST
and reinstall the two half-keys against the valve stem.