1948-1952 Shop Service Manual - - Hudson-Essex-Terraplane Club

ENGINE TUNE-UP 2 -13
3. Turn tester switch to Dwell-Ohm position, and adjust
Dwell-Ohm Regulator until meter reads on "Set" line.
4. After calibrating the Test Unit, separate the positive primary
and ground test leads, connect the positive primary
lead to the primary ignition wire which was removed
from the distributor, Figure 17.
5. Insert the short test lead into the high tension post of the
coil and connect the ground lead directly to the short test
lead.
IGNITION TIMING
For average operating conditions, both six and eight
cylinder engines should be set to fire at top dead center of
the compression stroke at cranking speed. When the long
mark before the UDC on the flywheel is lined up with the
pointer on the rear engine support plate, Figure 19, No. 1
piston is at top dead center. Ignition timing may be accurately
set by the use of a neon timing light as follows:
6. Meter should read from 2,000 to 10,000 OHM's resistance.
If the meter reads outside this range, replace coil.
SPARK PLUG MILLIAMPERE TEST:
1. Connect primary lead (Red Insulator) of the Coil Breaker
Unit to engine for a ground, the other primary lead (Black
Insulator) to the number one spark plug, Figure 18.
2. Run engine at idle speed, turn to switch to the Milliampere
position and read Coil Meter Milliampere Scale.
3. The reading should be the same at each spark plug. A low
reading (established on a comparative basis) may indicate
a weak coil, excessive resistance either in the primary or
secondary circuit, corroded terminals, or poor connections.
NOTE: The six cylinder distributor cap has a built-in resistor.
FIGURE 19
1. Connect one lead of the power timing light to the No. 1
spark plug, the other lead to the negative terminal of the
battery.
2. Place a chalk mark on the long timing mark on the
flywheel, Figure 20. Loosen
FIGURE 18
FIGURE 20