REPAIR INSTRUCTIONS
Page 195
VALVE SEAT INSERT INSTALLATION
Oversize inlet and exhaust valve seat inserts are
available in 0.005, 0.015, 0.031, 0.047 and
0.062 inch sizes if the counterbore requires
machining.
1. If required, machine the inlet and exhaust
valve seat insert counterbores using tool
HT77136.
2. Position the valve seat insert (1) over the
corresponding counterbore as shown in
Figure 198. Install the inserts using valve
seat insert installation set J 38586 (2). Use
driver handle J 8092 (3) to drive the valve
seat insert into the counterbore.
198
Figure 198 — Valve Seat Insert Installation
3. Grind the inlet/exhaust valve seat inserts to
specification.
r
Inlet valve inserts: 20
°
30
′ ±
15
′
angle
r
Exhaust valve inserts: 30
°
−
0
′
/+30
′
Always use 30-degree valves with 30-degree
valve inserts and 20-degree valves with
20-degree valve inserts. Excessive wear and
possible failure will result if 30-degree parts are
matched with 20-degree parts.
If valve seat insert widths exceed specifications
when grinding the inserts, use a 15-degree angle
grinding stone to obtain the correct width.
4. After grinding, thoroughly clean the valve
seat insert.
5. Determine the concentricity of each valve
seat insert relative to the valve guide. Valve
seat runout is to be held within 0.002 inch
(0.051 mm) FIM (Full Indicator Movement),
with finished valve guide ID measurements
made from snug-fitting arbor (1) and
through-mounted into finished valve guides
(2) as shown in Figure 199.
1. Valve Seat Insert
2. J 38586
3. J 8092
5_106_00.bk Page 195 Friday, August 4, 2000 11:17 AM
BDC for engine manuals and specs