Valve Seat - Install - Mitsubishi S12A2 Service Manual

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.
Item
Inside diameter of valve seat counterbore
Inlet
Valve seat outside diame-
ter
Inside diameter of valve seat counterbore
Exhaust
Valve seat outside diame-
ter
Valve seat interference
Inside diameter of valve seat counterbore
58.030 mm [2.2846 in.] or less
Inlet 58.030 [2.2846 in.] or more
58.060 [2.2858 in.] or more
54.030 mm [2.1272 in.] or less
Exhaust 54.030 [2.1272 in.] or more
58.060 [2.1283 in.] or more
(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.
Chapter 6 INSPECTION AND REPAIR OF BASIC ENGINE
Standard value
58.000 to 58.030 mm
[2.2835 to 2.2846 in.]
58.100 to 58.130 mm
Standard
[2.2874 to 2.2886 in.]
0.03 mm 58.130 to 58.160 mm
[0.0012 in.] [2.2886 to 2.2898 in.]
0.06 mm 58.160 to 58.190 mm
[0.0024 in.] [2.2898 to 2.2909 in.]
54.000 to 54.030 mm
[2.1260 to 2.1272 in.]
54.100 to 54.130 mm
Standard
[2.1299 to 2.1311 in.]
0.03 mm 54.130 to 54.160 mm
[0.0012 in.] [2.1311 to 2.1323 in.]
0.06 mm 54.160 to 54.190 mm
[0.0024 in.] [2.1323 to 2.1335 in.]
0.070 to 0.130 mm
[0.0028 to 0.0051 in.]
Applicable valve seat
Standard
0.03 mm [0.0012 in.]
0.06 mm [0.0024 in.]
Standard
0.03 mm [0.0012 in.]
0.06 mm [0.0024 in.]
Valve seat caulking tool
P/N:35A91-05010(Inlet)
60°± 15'
Valve seat fitting
bore inside diameter
Valve seat
outside diameter
Valve seat counterbore
Limit value
58.09 mm
[2.2870 in.]
-
-
-
54.09 mm
[2.1295 in.]
-
-
-
-
35A91-05020(Exhaust)
Valve Seat - Install
Unit: mm [in.]
Remarks
Single red line
Double red lines
Triple red lines
Double blue lines
Triple blue lines
Four blue lines
6-7