Installation Owner manual

ManualsBrandsMSD ManualsCar84891 Chevy Flat Top Pro-Billet Distributor

MSD Pro-Billet Flat-Top

Chevrolet V8 Distributor

PN 84891

1 - Advance Kit

1 - Gasket

1 - Tube of Gear Lubricant

2 - O-Rings

WARNING: Before installing the MSD Distributor, disconnect the battery cables. When discon-

necting the battery cables, always remove the Negative (-) cable ﬁrst and install it last.

Important: Read these instructions before attempting the installation.

Parts Included:

1 - Pro-Billet Distributor

1 - Rotor, PN 84673

1 - Distributor Cap, PN 8531

Note: The terminals of this Distributor require spark plug style terminals. You may need to change the

terminals and boots of your wires. MSD offers two kits, PN 8849 or PN 8848 that are supplied with

nine boots and terminals.

Note: If the gear is ever replaced, MSD Gear (PN 8531) is required for replacement due to the .500"

diameter shaft.

Note: For a replacement rotor, contact MSD Customer Support at 915-855-7123.

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 centrifu g a l advance added together.

Example: 10° Initial + 25° centrifugal = 35° Total Timing. (When checking Total timing, disconnect

the vacuum canister and plug the vacuum source.)

Note: MSD Distributors are supplied with the heavy (slow) advance springs installed. This is to prevent

detonation in certain applications. Review the information on pages 2-4 to determine the best

advance curve for your application.

M S D • W W W . M S D P E R F O R M A N C E . C O M • ( 9 1 5 ) 8 5 7 - 5 2 0 0 • F A X ( 9 1 5 ) 8 5 7 - 3 3 4 4

ONLINE PRODUCT REGISTRATION: Register your MSD product online and you’ll be entered

in our monthly 8.5mm Super Conductor Spark Plug Wire give-away! Registering your product

will help if there is ever a warranty issue with your product and helps the MSD R&D team create

new products that you ask for! Go to www.msdperformance.com/registration.

Summary of content (8 pages)

PAGE 1
MSD Pro-Billet Flat-Top Chevrolet V8 Distributor PN 84891 ONLINE PRODUCT REGISTRATION: Register your MSD product online and you’ll be entered in our monthly 8.5mm Super Conductor Spark Plug Wire give-away! Registering your product will help if there is ever a warranty issue with your product and helps the MSD R&D team create new products that you ask for! Go to www.msdperformance.com/registration. Important: Read these instructions before attempting the installation.
PAGE 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.
PAGE 3
INSTALLATION INSTRUCTIONS 3 CENTRIFUGAL ADVANCE CURVE Timing Curve From Factory 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 (Figure 2). The parts kit contains two additional sets of springs which can be used to match the advance curve to your particular application.
PAGE 4
INSTALLATION INSTRUCTIONS SELECTING THE ADVANCE STOP BUSHING BUSHING SIZE 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.
PAGE 5
INSTALLATION INSTRUCTIONS 5 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 or firewall. Note this position by making a mark (Figure 8). 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.
PAGE 6
INSTALLATION INSTRUCTIONS WARNING: High voltage is present on the coil terminals. Do not touch the terminals or coil tower when the engine is cranking or running. Figure 10 Wiring to an MSD 6-Series Ignition Control. Figure 11 Wiring to an MSD 7-Series Ignition Control. MSD • WWW.MSDPERFORMANCE.
PAGE 7
INSTALLATION INSTRUCTIONS 7 Note: MSD 6 and 7 Series Ignitions share the same color wiring. Figure 12 Wiring with an MSD 7-Series Ignition and Timing Control.
PAGE 8
TECH NOTES _________________________________________________________________________________________________________________________ _________________________________________________________________________________________________________________________ _________________________________________________________________________________________________________________________ _________________________________________________________________________________________________________________________ _____________