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Chapter 11
Valves, Lifters, Spring and Valve Seats
GeneraI Information
Valves must be in good condition, proper sealing and
proper gap must be maintained for full power, easy
starting and efficient operation.
Valve Removal
To remove valves, use a commercially available valve
spring compressor. Move the lower cap, so it will slip off
the end of the valve.
Clean all parts and remove carbon from valve heads and
stems. If valves are in usable condition, grind the valve
faces to a 45
o
angle.
NOTES
It is important to remove no more metal than required to
clean up and true the valve face.
Replace valves if they are damaged, distorted or if the
margin is ground to less than 1/32'’ (.79 mm).
Replace the valve if end of valve stem shows uneven wear.
After valves have been ground, handle with care to pre-
vent damage to the ground faces.
Do not use valves with
undersized margins. Doing so
may result in a valve that does not seat normally,
burns easily, and can also lead to valve cracking.
Valve Seats
Valve seats are not replaceable. If they are burned or
pitted, they can be reground using a grinding stone or
valve seat cutter.
The recommended procedure to properly cut a valve
seat is to use the Neway Valve Cutting System, which
consists of three different degree cutters. First, use the
60
o
cutter to clean and narrow the seat from the bottom
toward the center.
See Specifications Section for
Dimensions
Intake
Valve
Exhaust
Valve
46
o
Second, use the 31
o
cutter to clean and narrow the seat
from the top toward the center.
Seats are ground at an angle of 46
o
, to a width of 3/64"
(1.19 mm).
Bottom
Narrowing
Bottom
Narrowing Cutter
Seat
60
o
15
o
Top Narrowing Cutter
Seat
46
o
31
o
Margin
45
o
Face
Stem
1/32" (.79 mm)
Minimum Dimension
11-1
CAUTION
