Valves; Valve Seat Cutting Diagrams; View Of Valve Seats In Head; Narrowing Valve Seat At Top With 20 Cutter - Fiat 850 Sedan 1968 Shop Manual

58 FIAT· 850 PASSENGER CARS
VALVE SEAT CUTTING DIAGRAMS
Fig, 95 • Inclination angles of valve seats In head and valve
faces.
Fig. 96 - Narrowing valve seat at top with 200 cutter.
Fig. 97 - Narrowing valve seat at bottom with 7S
G
cutter.
Fig. 98 • View of a valve seat which has been reseated with
20" and 75° cutters.
Fig. 99 - View of valve seats in head.
A. Intake valve seat. • B. Exhaust valve seat.
VALVES
Checking and Refacing.
Remove carbon from valves using electric wire
brush M. 1042.
Check valve stern for cracks or distortions and
replace valve if either condition is evident.
The stern diameter, in a new valve, is .2750" to
.2756" (6.985 to 7.000 rom).
Check clearance between valve stern and valve
guide
(fig. 100):
it should be .0009" to .0022" (0.022
to 0.055).
Check valve head for excessive wear or damage;
if necessary. reface the valve using grinding machine
M. 1014 as follows:
Fig. 100 • Checking clearance of valve stem In guide.
1. Magnetic dial indicator.• 2. Valve part way out.