Volvo Penta 230 Workshop Manual page 18

IMPORTANT! The valves are stellite coated. Therefore they must not be machined, only lapped against the seat!
Clearance when checking:
Cold engine .........................................................................................
Hot engine ...........................................................................................
Clearance when adjusting:
Cold engine .........................................................................................
Hot engine ...........................................................................................
The same clearance for inlet and exhaust valves.
Valve guides (inlet & exhaust) 230, 250, AQ131, AQ151
Length .................................................................................................
Inner diameter .....................................................................................
Clearance, valve stem–valve guide, inlet valve ...................................
Clearance, valve stem–valve guide, exhaust valve ............................
Clearance, maximum wear ..................................................................
Valve springs, 230, 250, AQ131, AQ151
Length, unloaded .................................................................................
Length, loaded 285–325 N (28.5–32.5 kp) ...........................................
Length, loaded 725–805 N (72.5–80.5 kp) ...........................................
Valves 251DOHC, AQ171
Inlet
Disc diameter ......................................................................................
Stem diameter .....................................................................................
Valve seat angle ..................................................................................
Cylinder block seat angle ....................................................................
Seat width in cylinder head ..................................................................
Exhaust
Disc diameter ......................................................................................
Stem diameter .....................................................................................
Valve seat angle ..................................................................................
Cylinder block seat angle ....................................................................
Seat width in cylinder head ..................................................................
IMPORTANT! The valves are stellite coated. Therefore they must not be machined, only lapped against the seat.
16
44.5°
New: 7.945–7.960 (0.3128–0.3134)
Min: 7.925 (0.3120")
35.0
Exhaust valve
44.5°
New: 6.955–6.970 (0.2738–0.2744")
Min: 6.935 (0.2730")
34.5
Inlet valve
44.5°
New: 6.945–6.960 (0.2734–0.2740")
Min: 6.925 (0.2726")
31.5
Exhaust valve
0.30–0.40 mm (0.0118–0.0157")
0.35–0.45 mm (0.0138–0.0177")
0.35–0.40 mm (0.0138–0.0157")
0.40–0.45 mm (0.0157–0.0177")
52 mm (2.165")
8.00–8.02 mm (0.275–0.276")
0.03–0.06 mm (0.0012–0.00245")
0.04–0.07 mm (0.0016–0.0028")
0.15 mm (0.0059")
45.0 mm (1.772")
38.0 mm (1.496")
27.0 mm (1.063")
34.5 mm (1.358")
6.955–6.970 mm (0.2738–0.2744")
44.5°
45°
1.3–1.9 mm (0.0512–0.0748")
31.5 mm (1.240")
6.945–6.960 mm (0. 2734–0.2740")
44.5°
45°
1.7–2.3 mm (0.0669–0.0906")