Msd ignition PN 8388, PN318, PN340, PN360, PN 8386 Installation instructions

MSD Pro-Billet Ready-to-Run

Chrysler V8 Distributor

PN 8388; 318, 340, 360, PN 8386; 383, 400

PN 8387; 426, 440

Important: Read these Instructions before attempting the installation.

Parts Included:

1 - Pro-Billet Distributor
1 - Rotor, PN 8467
1 - Distributor Cap
1 - Advance Kit
1 - O-ring Seal
1 - Parts Bag

Note: The PN 8386 and PN 8387 distributors feature HEI style plug wire terminals. You may
need to change the terminals and boots of your wires. MSD offers a kit, PN 8848, that comes
with nine HEI style boots and terminals.

Replacement Cap

Distributor PN 8386, PN 8387 - PN 8431
Distributor PN 8388 - PN 8437 or PN 8433

:

TIMING FUNCTIONS

Before continuing with the installation, here are a few definitions you should be aware of:

Initial Timing: This is the base timing (also referred to as idle timing) of the engine before the
centrifugal advance begins.

Centrifugal Advance: The centrifugal (or mechanical) advance mechanism is made up of weights,
springs, advance cams, and an advance stop bushing. The amount and rate of advance that
your distributor is capable of is determined by the centrifugal timing. If you ever wish to lock out
the centrifugal advance, refer to the centrifugal advance section.

Total Timing: This is the total of the initial timing plus the centrifugal advance added together.
Example: 10° Initial + 25° centrifugal = 35° Total Timing. (When checking Total timing, disconnect
and plug the vacuum advance.)

Vacuum Advance: The vacuum advance will advance the timing up to 10° during partial throttle
driving (with 15 lbs of vacuum). The vacuum line should be routed to a ported vacuum outlet
above the throttle plates.

AUTOTRONIC CONTROLS CORPORATION • 1490 HENRY BRENNAN DR., EL PASO, TEXAS 79936 • [phone] • FAX [phone]

2 INSTALLATION INSTRUCTIONS

CHOOSING AN ADVANCE CURVE

The function of the advance curve is to match the ignition timing to the burning rate of the fuel
and speed (rpm) of the engine. Any factor that changes the burning rate of the fuel or the engine
speed can cause a need for an ignition timing change. Figure 1 shows some of the factors that
will affect engine timing.

FACTOR Advance Timing Retard Timing

For For

Cylinder Pressure Low High
RPM High Low
Vacuum High Low
Energy of Ignition Low High
Fuel Octane High Low
Mixture (Air/Fuel) Rich Lean
Temperature Cool Hot
Combustion Chamber Shape Open Compact
Spark Plug Location Offset Center
Combustion Turbulence Low High
Load Light Heavy

Figure 1 Ignition Timing Factors.

As you can see from the chart, most factors will change throughout the range of the engine
operation. The timing mechanism of the distributor must make timing changes based on these
factors.

Example: An engine has 11:1 compression, a high energy ignition and turns 5,500 rpm. With
the specifications given, you will have to retard the timing for the high compression, low rpm
and high energy ignition. By comparing the engine’s specifications against the chart, a usable
timing guideline can be found. Engines with a combination of items from both columns will
require a timing that is set in the mid range.

Obviously a full technical explanation of correct ignition timing would be very complicated. The
best way to arrive at a suitable ignition curve for your engine is to use the Ignition Timing Factors
Chart as a guide and compare it to the Advance Graphs in Figure 4 until a suitable curve is found.
When selecting your advance curve, use detonation (engine ping) as an indicator of too much
advance, and a decrease in power as an indicator of too little advance.

TIPS ON SELECTING AN ADVANCE CURVE

• Use as much initial advance as possible without encountering excessive starter load.

• Start the centrifugal advance just above the idle rpm.

• The starting point of the centrifugal advance curve is controlled by the installed length and
tension of the spring.

• How quickly the centrifugal advance (slope) comes in is controlled by the spring stiffness. The
stiffer the spring, the slower the advance curve.

• The amount of advance is controlled by the advance bushing. The bigger the bushing, the
smaller the amount of advance.

AUTOTRONIC CONTROLS CORPORATION • 1490 HENRY BRENNAN DR., EL PASO, TEXAS 79936 • [phone] • FAX [phone]

INSTALLATION INSTRUCTIONS 3

CENTRIFUGAL ADVANCE CURVE

SELECTING THE ADVANCE SPRINGS

The rate, or how quick the advance comes in is determined by the type of springs which are
installed on the distributor. The MSD distributors are equipped with two Heavy Silver springs
installed. These will give you the slowest advance curve possible. The parts kit contains two
additional sets of springs which can be used to match the advance curve to your particular
application. Refer to the Spring Combination Chart (Figure 3) for combinations that can be
achieved.

To change the springs, remove the cap and rotor and use needlenose pliers to remove the springs.
Be sure the new springs seat in the groove on the pin.

Timing Curve From Factory

SPRING COMBINATION RATE OF ADVANCE FIGURE 4 (Page 3)

2- Heavy Silver SLOWEST A
1- Heavy Silver B
1- Light Blue
1-Heavy Silver C
1-Light Silver
2- Light Blue D
1- Light Silver E
1- Light Blue
2- Light Silver FASTEST F

Figure 2 The Factory Equipped Curve. Figure 3 Spring Combination Chart.

Figure 4 Advance Curves.

AUTOTRONIC CONTROLS CORPORATION • 1490 HENRY BRENNAN DR., EL PASO, TEXAS 79936 • [phone] • FAX [phone]

4 INSTALLATION INSTRUCTIONS

SELECTING THE ADVANCE STOP BUSHING

Three different advance stop bushings are supplied in the distributor kit. The distributor comes
with a Blue (21°) bushing already installed. If a different amount of centrifugal advance is
desired, follow the next procedure to change the bushings. The chart in Figure 5 gives the size
and approximate degrees for the corresponding bushings.

BUSHING APPROXIMATE CRANKSHAFT
DIAMETER DEGREES

Red - 0.283" 28°
Silver - 0.313" 25°
Blue - 0.343" 21°
Black - 0.375" 18°

Figure 5 Advance Stop Bushing Chart.

CHANGING THE ADVANCE STOP
BUSHINGS

1. Remove the distributor cap and rotor.

2. Remove the locknut and washer on the bottom
of the advance assembly (Figure 6).

3. Remove the bushing and install the new one.
Install the washer and locknut.

Figure 6 Changing the Advance Stop Bushing.

LOCKING OUT THE CENTRIFUGAL ADVANCE

1. Remove the cap and rotor.

2. Remove the advance springs, weights
and the advance stop bushing from the
advance assembly.

3. Remove the roll-pin from the shaft and
slide the retaining sleeve down (Figure 7).

4. Slide the shaft two inches out of the
housing.

Figure 7 Removing the Retaining Sleeve.

AUTOTRONIC CONTROLS CORPORATION • 1490 HENRY BRENNAN DR., EL PASO, TEXAS 79936 • [phone] • FAX [phone]

INSTALLATION INSTRUCTIONS 5

5. Rotate the shaft 180° and insert the
advance stop bushing pin into the small
hole on the advance plate (Figure 8).

6. Install the locknut and washer to the
advance stop bushing pin.

7. Install the retaining sleeve and roll-pin.

Figure 8 Locking Out the Centrifugal Advance.

INSTALLING THE DISTRIBUTOR

1. Remove the existing distributor cap

without disconnecting any of the spark
plug wires.

2. With the cap off, crank the engine until

the rotor is aimed at a fixed point on
the engine.Note this position by making
a mark (Figure 9).

3. Place the distributor cap back on and

note which plug wire the rotor is
pointing to. MARK THE SPARK PLUG
WIRES and remove the distributor cap.

4. Disconnect the wiring from the

distributor.

5. Loosen the distributor hold-down

clamp,slide the clamp out of the way
and lift the distributor out of the engine.

6. Install the supplied O-ring seal in the

groove on the distributor land. Apply
a thin layer of oil to the housing O-ring.

7. Install the distributor making sure that

the rotor comes to rest pointing at the

Figure 9 Marking the Rotor Location.

fixed mark. If the distributor will not fully seat with the rotor pointing to the marked position,
you may need to rotate the oil pump shaft until the rotor lines up and the distributor fully
seats.

8. Position and tighten the hold-down clamp onto the distributor.

9. Install the rotor and distributor cap. It is recommended to use a drop of Blue Loctite on the

distributor cap hold down bolts.

10. Install the spark plug wires from the old cap one at a time to ensure correct location.

11. Connect the supplied wiring harness to the distributor. Route the wires to their

connections as shown in Figure 10.

AUTOTRONIC CONTROLS CORPORATION • 1490 HENRY BRENNAN DR., EL PASO, TEXAS 79936 • [phone] • FAX [phone]

6 INSTALLATION INSTRUCTIONS

Figure 10 Wiring the Ready-to-Run Chrysler Distributor.

Figure 11 Connecting an MSD Ignition Control.

AUTOTRONIC CONTROLS CORPORATION • 1490 HENRY BRENNAN DR., EL PASO, TEXAS 79936 • [phone] • FAX [phone]

INSTALLATION INSTRUCTIONS 7

Tech Notes

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AUTOTRONIC CONTROLS CORPORATION • 1490 HENRY BRENNAN DR., EL PASO, TEXAS 79936 • [phone] • FAX [phone]

TECH NOTES

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Service

In case of malfunction, this MSD component will be repaired free of charge according to the terms
of the warranty. When returning MSD components for service, Proof of Purchase must be supplied for
warranty verification. After the warranty period has expired, repair service is charged based on a minimum
and maximum charge.

Send the unit prepaid with proof of purchase to the attention of: Customer Service Department,
Autotronic Controls Corporation, 12120 Esther Lama, Suite 114, El Paso, Texas 79936.

When returning the unit for repair, leave all wires at the length in which you have them installed.
Cutting wires close to the unit will void your warranty. Be sure to include a detailed account of any
problems experienced, and what components and accessories are installed on the vehicle.

The repaired unit will be returned as soon as possible after receipt, COD for any charges. For more
information, call the MSD Customer Service Line [phone]. MSD technicians are available from
8:00 a.m. to 5:00 p.m. Monday - Friday (mountain time).

Limited Warranty

A

utotronic Controls Corporation warrants MSD Ignition products to be free from defects in material
and workmanship under normal use and if properly installed for a period of one year from date of
purchase. If found to be defective as mentioned above, it will be replaced or repaired if returned prepaid
along with proof of date of purchase. This shall constitute the sole remedy of the purchaser and the sole
liability of Autotronic Controls Corporation. To the extent permitted by law, the foregoing is exclusive
and in lieu of all other warranties or representations whether expressed or implied, including any implied
warranty of merchantability or fitness. In no event shall Autotronic Controls Corporation be liable for
special or consequential damages.

AUTOTRONIC CONTROLS CORPORATION • 1490 HENRY BRENNAN DR., EL PASO, TEXAS 79936 • [phone] • FAX [phone]

FRM25013 Revised 5/03 Printed In U.S.A.