75SERIES datasheet(4/8 Pages) MALLORY

4 / 8 page

www.malloryracing.com

MALLORY IGNITION

ADJUSTING THE AMOUNT OF MECHANICAL

ADVANCE (IF NECESSARY)

The distributor mechanical (centrifugal) advance

mechanism is adjusted at the factory to limit the

mechanical advance to 24°. In most cases, this will

work fine. However, in some rare cases, it may be

beneficial to change the factory setting. The adjustment

range is zero to 28°. If the limit is changed, it may be

necessary to change the initial timing as well.

To access the mechanical advance, remove the

distributor cap, rotor, rotor flange bolt and rotor flange.

Remove the module. Using a small puller, remove the

reluctor. Do not lose the small pin that locates the

reluctor. Remove the two set screws. Lift out pickup

plate assembly (See Figure 4). See Page 7 for

instructions on adjusting the mechanical advance limit.

CHANGING THE MECHANICAL

ADVANCE RATE

The advance springs installed at the factory produce

an advance curve that starts at 1200 rpm and is all-in

by 3200 rpm. If a faster or slower advance curve is

required, a spring kit (PN 29014) can be purchased

from Mallory dealers.

REPLACING THE MALLORY MODULE WITH AN

OEM STYLE MODULE

While the use of stock/OEM type modules will reduce

the spark energy and eliminate the rev limiter, in an

emergency, an OEM style HEI module can be used.

Cut the wire harness off of another module and attach

as shown in the photo on Figure 5.

SETTING THE INITIAL TIMING

Connect a timing light to the engine. Do not connect

the vacuum advance at this time. Start the engine

and allow it to warm up a few minutes at idle. If the

engine will not start or idle smoothly, try rotating the

distributor (in either direction) to get the timing closer

to optimum. If the engine will not start, the firing

order may be incorrect, or the rotor may not be

aligned correctly. Consult a repair manual for more

information.

Check the initial timing with the timing light. The

engine must be at idle (under 1200 rpm). Set the

initial timing between 5° and 12° BTDC and tighten

the clamp.

With the vacuum advance line still disconnected

and plugged, take the vehicle for a test drive. Listen

carefully while under full throttle in high gear. If you

hear knocking or pinging, reduce the initial timing by

2 degrees at a time until you no longer hear the engine

pinging or knocking. If you do not hear pinging or

knocking, increase initial timing by 2 degrees at a time

until you hear it, then reduce timing by 2 degrees.

Initial timing should never be less than 0 degrees or

more than 16 degrees. If the engine seems to run best

outside this range, something else is wrong. Find the

problem before continuing.

ADJUSTING THE VACUUM ADVANCE

The vacuum chamber is adjusted at the factory to

produce 12° of additional advance at steady speeds.

This may be too much for some engines. Connect a

vacuum line from the vacuum chamber to a ported

vacuum source on the carburetor. Take the vehicle for

another test drive. Drive the vehicle at a steady speed

in high gear on a highway that is level or slightly

inclined. If surging or pinging is noticed, the amount

of vacuum advance must be reduced. Pull the vacuum

line off the vacuum chamber. Insert a 3/32" allen

wrench into the chamber nipple and turn the

adjustment screw counterclockwise two turns.

Reconnect the hose and take another test drive.

Reduce the vacuum advance further if necessary to

eliminate surging or pinging.

WARNING:

The wire from the ignition switch must not be a

resistor type wire or contain a ballast resistor. If

your car has a ballast resistor, remove it or put a

jumper wire across it. If your car uses a resistor

wire for the ignition (many pre-1975 vehicles do),

you must run a different wire to the distributor from

the ignition key (or fuse box) so that full battery

voltage reaches the distributor. The distributor

will operate with a ballast or resistor wire, but

performance will be greatly reduced. To determine

if your car has a resistor wire, check the voltage of

the wire at the coil with the engine running. If the

voltage is within 1.5 volts of the battery voltage,

the wire is not a resistor type. If the voltage is not

within 1.5 volts of battery voltage, you must run a

new wire to the distributor.

75SERIES Datasheet(PDF) 4 Page - Mallory performance club

75SERIES Datasheet(HTML) 4 Page - Mallory performance club

Html Pages

1 2 3 4 5 6 7 8

Datasheet Download

Link URL