TM 9-3431-254-14&P
cylinders are numbered from 1 to 4 on the cylinder
head covers.
TIMING MARKS (Refer to Fig. B-10)
Remove screen over flywheel air intake opening by
taking out the screws holding screen in place. This
will expose the timing marks on flywheel shroud, also
the vane on flywheel marked by an 'X' and the letters
`DC'.
NOTE: On engines equipped with a rotating screen
attached to the flywheel, the leading edge of the `X'
marked vane is identified by an `I' stamped on the
outer rim of the screen, thereby not requiring removal
of the rotating screen when timing the engine.
TIMING INSTRUCTIONS: The No. 1 piston must be
on top dead center of the compression stroke before
distributor can be mounted. With reference to Fig. B-10,
this can be accomplished as follows:
or stud in an approximate 12 o'clock position.
1. Remove rocker arm cover from No. 1 cylinder bank.
d . Mount distributor clamp to drive housing, Fig. B-11,
but do not tighten screw. If applicable, as per
2. Turn engine over with hand crank until the inlet
valve opens and then closes.
the drive housing.
3. Continue turning the engine over until the leading
e . Adjust breaker point gap to 0.020 inch maximum
edge of the 'X' marked vane on the flywheel is in
line with the centerline mark of the No. 1 and 3
opening, see `Distributor Maintenance'.
cylinder-banks.
f . With the clamp screw loose, turn distributor body
4. DISTRIBUTOR TIMING: With the No. 1 piston now
slightly in a counter-clockwise rotation so that
on TDC of the compression stroke, refer to Fig. B-11
breaker points are firmly closed. Then turn dis-
tributor body in a clockwise rotation until break-
for the revised Delco-Remy distributor or Fig. B-12
er points are just beginning to open. At this
for Prestolite, and mount distributor as follows:
point a slight resistance can be felt as the
a. Before mounting distributor to housing, take off
breaker point cam strikes the breaker arm.
distributor cap, remove rotor and dust cover.
g. Tighten clamp screw. The No. 1 cylinder is now
b. Hold distributor with face up and terminal wire
ready to fire in the retarded position.
or terminal stud, away and in a 12 o'clock posi-
tion as shown. Mount rotor on shaft and turn un-
The breaker point gap of 0.020 of an inch should be
til the rotor contact points in an approximate 2
checked and adjusted per paragraph (e), before dis-
o'clock position as illustrated in Fig B-11, or 1
tributor body is set and locked in place, as per para-
o'clock position as in Fig. B-12.
graphs (f) and (g), because any change in gap open-
c. Assemble distributor to housing, properly mesh-
ing will affect the ignition advance. Mount dust cover
ing the gears while retaining the terminal wire
and distributor cap.
