Yanmar ViO12-2A, Service Manual

Page: 42 / 409

3. SERVICING STANDARDS
3-2-1
3-2 Engine
1) Nominal and Allowable Values
ViO12
-2A
Applicable model 3TNV70-WBVB
Item Unit Standard Wear limit
Cylinder head
Cylinder head distortion mm 0
,
05 or less 0
,
15
Valve seat angle
Intake
degrees
( ° )
120

Exhaust 90

Valve seat width
Intake
mm
 
Exhaust
 
Intake valve
Stem outside dia.
mm
5
,
960 to 5
,
975
5
,
90
Guide inside dia.
6
,
000 to 6
,
012
6
,
08
Oil clearance
0
,
025 to 0
,0
52
0
,
16
Exhaust valve
Stem outside dia.
mm
5
,
945 to 5
,
960
5
,
90
Guide inside dia.
6
,
000 to 6
,
012
6
,
08
Oil clearance
0
,
040 to 0
,
067
0
,
17
Valve guide projection mm 9
,
8 to 10
,
0

Valve sinkage
Intake
mm
0
,
4 to 0
,
6
0
,
8
Exhaust
0
,
4 to 0
,
6
Valve head
thickness
Intake
mm
0
,
9 to 1
,
1
0
,
5
Exhaust
1
,
0 to 1
,
2
Intake valve
operating timing
Open b. TDC
degrees
( ° )
7 to 17

Close a. BDC 35 to 45

Exhaust valve
operating timing
Open b. BDC
degrees
( ° )
35 to 45

Close a. TDC 7 to 17

Valve spring
Free length mm 37.8

Inclination mm

1
,
3
Tension 1 mm compressed] N
8
,
95 to 11
,
49

Intake / exhaust valve clearance mm
0
,
15 to 0
,
25

Cylinder block
Cylinder bore dia.
mm
70
,
010 to 70
,
020
70
,
200
Roundness of cylinder sleeve bore
0
,
01 or less 0
,
03
Cylindricity of cylinder sleeve bore