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22
491-76984 the mechanical advance range was
modified. These distributor assemblies may be
identified by the vendor part number on the name
plate: IGS-4213-1 has a 12 degree advance and
IGS-4213A-1 has a 8.5° degree advance.
The change in vacuum and mechanical advance
must be taken into consideration when testing the
distributor. Refer to the specification section of the
"Electrical Section" for the latest specifications.
VACUUM ADVANCE - PAGE 6-17
(8 CYLINDER)
Effective with car number 494-114018 the 8
cylinder distributor vacuum advance was changed
from a maximum of 8.5 degrees to 4 degrees at the
distributor. The mechanical advance has not been
changed.
The new distributor with the 4° plate has part
number IGT-4204 B-1 on the distributor housing
and has a small figure 4 stamped on the breaker plate
just opposite the vacuum control diaphragm, Figure
3.
FIGURE 3
The first type distributor carries part No. IGT-
4204A-1 and has a figure 8.5 stamped on the
breaker plate. Refer to the specification section of
the "Electrical Section" for the latest specifications.
SPARK SETTING - PAGE 6-17
Paragraph three should read: Correct spark setting
is obtained with the number one cylinder at top dead
center, rotor facing No. 1 terminal of distributor cap
with distributor set in mid-position in the quadrant
and points just beginning to open.
IGNITION TIMING - PAGE 6-20
The flywheel markings were revised after April
21, 1949 as follows: "U.D.C. 1-6", and "U.D.C. 1-8"
have been changed to "U.D.C. 1" for both 6 and 8
cylinder engines. The figures 6 and8 immediately
following figure "U.D.C. 1" have been removed.
Figure 4.
FIGURE 4
The change in marking will not effect the proce-
dures for the setting of "Ignition timing" and "Fuel
and Altitude Compensation" as outlined on pages
6-20 and 6-21 - 480-490 Mechanical Procedure
Manual.
SPARK PLUGS - PAGE 6-21
The new H-8 Champion spark plugs will replace
Champion J-7 or J-9 for cast iron cylinder heads and
replace Champion H-10 for aluminum heads.
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