Caution: The cap and body seat
A f t e r refacing the valves, check the
must be an airtight seat, since it is a
thickness from the top of the head to
point at which the energy cell is sealed
the edge of the refaced outer surface.
i n t o the head and any leakage would
This can be accomplised by comparing
cause burning of the surrounding
t h e refaced valve with a new one. If
metal in a short time.
t h e refaced valve has 50 percent less
margin, replace the valve.
(8) A f t e r t h e v a l v e s h a v e b e e n r e f a c e d
80. Cylinder Head Assembly Reassembly
a n d the valve seats in the block re-
and Installation
finished, the valve and seats should be
a. Reassembly. Refer to figure 25, and re-
ground (lapped). Place a small
assemble the cylinder head assembly in the re-
amount of medium grade grinding
v e r s e order.
compound around the face of the
valve. Place a light spring under each
C a u t i o n : Make certain that the energy cells
valve and lap into place.
have been torqued from 35 to 40 foot-pounds to
Note. Avoid continuous round-and-round
i n s u r e against possible leaking from the com-
motions that would cut grooves in the valve
b u s t i o n chamber at either the seat where the
or seat. Rotate only part of a turn with a
b o d y contacts the head or the contact surface
suitable tool, then raise it off the seat and
between the cap and the body.
move it to a new position and then repeat
the process
b. Installation.
(9) T e s t e a c h v a l v e f o r a t i g h t s e a t b y
(1) Refer to figure 23, and install the cyl-
m a k i n g pencil marks across the face
inder head assembly on the engine.
of the valve at short intervals, and
t h e n rotate the valve against its seat
( 2 ) Install the rocker arm assembly (par.
f o r part of a turn with firm pressure
76).
a n d again lift out and observe if the
(3) If water pump was removed, install
pencil marks are all rubbed out on the
t h e pump (par. 48).
c o n t a c t surfaces; if not, regrind until
fold (TM 5-3820-205-20/l).
t h i s test shows a gastight mating of
( 4 ) Install the intake and exhaust mani-
valve to seat. It is imperative that
fold (TM 5-3820-205-20/l).
t h e valves then be assembled in the
same seats to which they were ground.
(5) Install the water manifold (TM 5-
3820-205-20/l).
(10) Lap the energy cell body into the head
w i t h valve grinding compound using
(6) Install the fuel injector assemblies
the puller or a piece of wood of such
(TM 5-3820-205-20/l).
s i z e that it can be screwed into the
(7) Adjust the valves (TM 5-3820-205-
threads in the energy cell, and lapped
20/l).
in the same manner as you would a
valve in a cylinder head.
( 8 ) Install the valve covers (TM 5-3820-
205-20/l).
(11) T h e c o n t a c t s u r f a c e w h e r e t h e c a p
s e a t s on the body must be lapped to
(9) Install the engine housing (TM 5-
make an airtight seat.
3820-205-20/l).
Se c t ion
XII.
V lBRAT lON
DAM PER
AN D
DRI V E
PU LLEY
81. General
disks. One disk is mounted rigidly, while the
other is free to rotate, limited only by the
The vibration damper is mounted on the
elasticity of the rubber. The purpose of the
f r o n t of the engine drive pulley. It is a fly-
w h e e l - t y p e disk that is made from two steel
v i b r a t i o n damper is to reduce or damper tor-
65
AGO 8498A