Mitsubishi S12A2 User Manual

6-7
Chapter 6 INSPECTION AND REPAIR OF BASIC ENGINE
1.8.3 Valve Seat - Install
(1) Before installing the valve seat, measure the inside
diameter of valve seat counterbore in cylinder head and
the outside diameter of valve seat to make sure that the
interference is within the range of standard value.If the
value exceeds the standard, use the oversize valve
seat.If the inside diameter of valve seat counterbore in
cylinder head exceeds the limit, replace the cylinder
head with a new one.
Note: Oversized valve seats are available in 0.03 and 0.06
mm [0.0012, 0.0024 in.] sizes.
Valve seat counterbore
(2) Cool the valve seat at least for 4 minutes in liquid nitro-
gen and cool the cylinder head to a room temperature.
(3) Install the valve seat into the cylinder head with valve
seat caulking tool.
Valve Seat - Install
Valve seat fitting
bore inside diameter
Valve seat
outside diameter
3 [0.118]
3 [0.118]
9 [0.35]
9 [0.35]
12
+0.1 0
[0.472
+0.004 0
]
60°± 15'
Unit: mm [in.]
3 [0.118]
9 [0.35]
Item Standard value Limit value Remarks
Inlet
Inside diameter of valve seat counterbore
58.000 to 58.030 mm
[2.2835 to 2.2846 in.]
58.09 mm
[2.2870 in.]
Valve seat outside diame-
ter
Standard
58.100 to 58.130 mm
[2.2874 to 2.2886 in.]
- Single red line
0.03 mm
[0.0012 in.]
58.130 to 58.160 mm
[2.2886 to 2.2898 in.]
- Double red lines
0.06 mm
[0.0024 in.]
58.160 to 58.190 mm
[2.2898 to 2.2909 in.]
- Triple red lines
Exhaust
Inside diameter of valve seat counterbore
54.000 to 54.030 mm
[2.1260 to 2.1272 in.]
54.09 mm
[2.1295 in.]
Valve seat outside diame-
ter
Standard
54.100 to 54.130 mm
[2.1299 to 2.1311 in.]
- Double blue lines
0.03 mm
[0.0012 in.]
54.130 to 54.160 mm
[2.1311 to 2.1323 in.]
- Triple blue lines
0.06 mm
[0.0024 in.]
54.160 to 54.190 mm
[2.1323 to 2.1335 in.]
- Four blue lines
Valve seat interference
0.070 to 0.130 mm
[0.0028 to 0.0051 in.]
-
Inside diameter of valve seat counterbore Applicable valve seat
Inlet
58.030 mm [2.2846 in.] or less Standard
58.030 [2.2846 in.] or more 0.03 mm [0.0012 in.]
58.060 [2.2858 in.] or more 0.06 mm [0.0024 in.]
Exhaust
54.030 mm [2.1272 in.] or less Standard
54.030 [2.1272 in.] or more 0.03 mm [0.0012 in.]
58.060 [2.1283 in.] or more 0.06 mm [0.0024 in.]
Valve seat caulking tool
P/N:35A91-05010(Inlet)
35A91-05020(Exhaust)

Mitsubishi S12A2 Specifications

General

Brand	Mitsubishi
Model	S12A2
Category	Engine
Language	English