Group 9 Ignition System

9-1

PART 9-1 PAGEGENERAL IGNITION SYSTEM SERVICE. .9-1

PART 9-2LOADOMATIC DISTRIBUTORS. . . . . . . .9-20

PART 9-3DUAL ADVANCE DISTRIBUTORS. . . . . .9-24

PAGEPART 9-4CENTRIFUGAL ADVANCE

DISTRIBUTORS. . . . . . .

PART 9-5SPECIFICATIONS. . . . . . .

.. .9-30

9-35

GENERAL IGNITION SYSTEM SERVICE

Page. . . .9-1

. . . .9-1

Section Page2 Common Adjustments and Repairs .9-14

Breaker Points and Condenser .9-14Ignition Timing 9-16Spark Plug Wire Replacement. . . . . . . . . . . . . . 9-16Spark Plugs 9-17Resistance Wire Replacement. . . . . .. . . . . . .. .9-17

3 Cleaning and Inspection .9-18Spark Plugs 9-18Distributors 9-18Secondary Wiring 9-18Coil. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-18Distributor Cap 9-18Rotor 9-18

9-2

.9-4

.9-9

Section1 Diagnosis and Testing.. . . . . . . . . . .

General Information Ignition System Tests-Conventional

Test Equipment Ignition System Tests-Rotunda

Oscilloscope Testers. . . . . . . . . . . .Distributor Checks Distributor Tests-Rotunda RE-27-44

Dwell Tester , Distributor Tests-Rotunda RE-236

Distributor Tester : Distributor Tests-Rotunda RE-1416

Distributor Tester. . . . . . . . . . . . . .

.9-10

. .9-10

... .9-12

ber is stamped on the distributorhousing. The basic part number forungoverned distributors is 12127. Toprocure replacement parts, it is nec-essary to know the part No. prefixand suffix and, in some cases, the de-

sign code change (Fig. 1).

Always refer to the Master Parts

Catalog for parts usage and inter-

changeability before replacing a dis-

tributor or a component part for a

distributor.

PART NUMBER PREFIX

PART NUMBER SUFFIX

~;-rJ~ J ~rhu~~ lr-r;;U~M C~ D I-l~~~ J

DESIGN CHANGE

ASSEMBLY CDDE (YEAR, MONTH, WEEK)

B2574.A

FIG. l-Distributor Identification

This part covers ignition systemdescription and operation, general ig-nition system diagnosis, tests, adjust-ments and repair operations. In ad-dition, the cleaning and inspectionprocedures are covered.

For distributor removal, disassem-bly, assembly, installation, major re-pair procedures and specifications,refer to the pertinent part of this

group.The distributor identification num-

The secondary circuit consists ofthe:

1. Secondary windings of the igni-tion coil.

2. Distributor rotor.3. Distributor cap.

2. Ignition switch.3. Primary circuit resistance wire.4. Primary windings of the igni-

tion coil.5. Breaker points.6. Condenser.

GENERAL INFORMATIONThe ignition system consists of a

primary (low voltage) and a second-ary (high voltage) circuit (Fig. 2).

The primary circuit consists of the:1. Batterv.

9-2 GROUP 9 IGNITION SYSTEM

IGN!~N,,/START r-~~ SPARK PLUG

.

";::TERMINAL CONNECTORPRIMARY RESISTANCE WIRE

~ : 6......

IGNmONSWITC~

dATTER'

DISCO

RELAY ~,-COil

+

-.

BATTERY

~

DISTRIBUTOR

secondary circuit can be caused by:1. Fouled or improperly adjusted

spark plugs.2. Defective high tension wiring.3. High tension leakage across the

coil, distributor cap or rotor result-ing from an accumulation of dirt.

To isolate a trouble in the second-ary circuit, proceed as follows:

Turn the ignition switch off andremove the auxiliary starter switchfrom the starter relay.

Install the coil high tension lead inthe distributor cap, the red and bluewire on the starter relay S terminaland the brown wire on the starter re-lay I terminal.

Now perform a secondary circuittest.

PRIMARY CIRCUIT TESTSA complete test of the primary cir-

cuit consists of checking the circuitfrom the battery to the coil, the cir-cuit from the coil to ground, and thestarting ignition circuit.

Excessive voltage drop in the pri-mary circuit will reduce the second-ary output of the ignition coil, result-ing in hard starting and poor per-formance.

Battery to Coil Test1. Connect the voltmeter leads as

shown in Fig. 3.2. Install a jumper wire from the

distributor terminal of the coil to agood ground on the distributor hous-ing.

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B2000-B

FIG. 3-Battery to Coil andStarting Ignition Circuit Test

- PRIMARY CIRCUIT " SECONDARY CIRCUIT

FIG. 2-Typical Ignition System (i

4. High tension wires.s. Spark plugs.When the breaker points are

closed, the primary or low voltagecurrent flows from the batterythrough the ignition switch to theprimary windings in the coil, then toground through the closed breakerpoints. When the breaker pointsopen, the magnetic field built up inthe primary windings of the coilmoves through the secondary wind-ings of the coil producing high volt-age current. High voltage current isproduced each time the breakerpoints open. The high voltage flowsthrough the coil high tension lead tothe distributor cap where the rotordistributes it to one of the spark plugterminals in the distributor cap. Thisprocess is repeated for every powerstroke of the engine.

IGNITION SYSTEM TESTS-CONVENTIONAL TESTEQUIPMENT

TROUBLE ISOLATIONIgnition system troubles are caused

by a failure in the primary and/ orthe secondary circuit or incorrect ig-nition timing. If an engine troublehas been traced to the ignition systemfrom the "Engine Trouble DiagnosisGuide," the trouble can be found byperforming an ignition system test ona scope or by further isolating thetrouble to the primary or secondarycircuit as follows:

1. Disconnect the brown wirefrom the starter relay I terminal and

IQUICKNNECT

~

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'cuit

the red and blue wire from the start-er relay S terminal.

2. Remove the coil high tensionlead from the distributor cap.

3. Turn on the ignition switch.4. While holding the high tension

lead approximately 3/16 inch from thecylinder head or any other goodground, crank the engine by using anauxiliary starter switch between thestarter relay battery and S terminals.

If the spark is good, the troublelies in the secondary circuit.

If there is no spark or a weakspark, the trouble is in the primarycircuit, coil to distributor high ten-sion lead, or the coil.

Primary CircuitA breakdown or energy loss in the

primary circuit can be caused by:1. Defective primary wiring, or

loose or corroded terminals.2. Burned, shorted, sticking or im-

properly adjusted breaker points.3. A defective coil.4. A defective condenser.To isolate a trouble in the primary

circuit, proceed as follows:Turn the ignition switch off and

remove the auxiliary starter switchfrom the starter relay.

Install the coil high tension lead inthe distributor cap, the red and bluewire on the starter relay S terminaland the brown wire on the starter re-lay I terminal.

Now perform a primary circuittest.

Secondary CircuitA breakdown or energy loss in the

9-3PART 9-1 - GENERAL IGNITION SYSTEM SERVICE

2. Install a jumper wire from thedistributor terminal of the coil to agood ground on the distributor body.

3. Turn all of the accessories andlights off.

4. Turn the ignition switch on.5. If the voltmeter reading is 0.3

volt or less, the ignition switch andthe relay to switch wire are satisfac-tory.

6. If the voltmeter reading isgreater than 0.3 volt, either the ig-nition switch and/ or the wire are de-fective.

Resistance Wire Test1. Connect the voltmeter leads as

shown in Fig. 5.

3. Turn the lights and accessoriesoff.


volts or less, the primary circuitfrom the battery to the coil is satis-factory.

6. If the voltmeter reading isgreater than 6.9 volts, check the fol-lowing:

The battery and cables for looseconnections or corrosion.

The primary wiring for worn insu-lation, broken strands, and loose orcorroded terminals.

The resistance wire for defects.The starter relay to ignition switch

for defects.

Starting Ignition Circuit Test1. Connect the voltmeter leads as

shown in Fig. 3.2. Disconnect and ground the coil

to distributor high tension lead at thedistributor.

3. With the ignition switch off,crank the engine by installing a jump-er wire between the battery and the"S" terminal of the starter relay whileobserving the voltage drop.

4. If the voltage drop is 0.1 voltor less, the starting ignition circuit issatisfactory .

5. If the voltage drop is greaterthan 0.1 volt, clean and tighten theterminals in the circuit or replace thewiring as necessary.

Ignition Switch Test1. Connect the voltmeter leads as

shown in Fig. 4.

volt or less, the primary circuit fromcoil to ground is satisfactory.

6. If the voltmeter reading isgreater than 0.1 volt, test the voltagedrop between each of the following:

The coil and breaker point termi-nals of the coil to distributor primarywire.

The movable breaker point and thebreaker plate.

The breaker plate and the distri-butor housing.

The distributor housing and engineground.

Breaker PointsClean and inspect the breaker

points by following the procedure un-der Cleaning and Inspection (Section3 of this part).

The breaker point dwell can bechecked with a distributor tester or adwell meter by following the proce-dure under Distributor Tests in thissection of the manual.

The breaker point resistance canbe checked with a Rotunda RE-1416distributor tester by following theprocedure under Distributor Tests inthis section of the manual.

,ACCESSORY

TERMINAL

+"'\

62004-6

FIG. 5-Resistance Wire Test

2. Install a jumper wire from thedistributor terminal of the coil to agood ground on the distributor hous-ing.

3. Turn all of the accessories andlights off.


volts or less, the resistance wire issatisfactory.

6. If the voltmeter reading isgreater than 6.6 volts, replace the re-sistance wire.

Coil to Ground Test1. Connect the voltmeter leads as

shown in Fig. 6.2. Close the breaker points.3. Turn all lights and accessories

off.

CoilClean and inspect the coil by fol-

lowing the procedure under Cleaningand Inspection (Section 3 of this

part).Check the coil on a coil tester by

following the manufacturers instruc-tions.

82002-8

FIG. 4-lgnition Switch Test4. Turn the ignition switch on.S. If the voltmeter reading is O.

SECONDARY CIRCUIT TESTS but weak or intermittent, check thecoil, distributor cap and the coil todistributor high tension wire.

the power plug into a proper AC out-let.

Spark PlugsInspect, clean and gap the plugs

following the instructions in sections2 and 3, After the proper gap is ob-tained, check the plugs on a testingmachine. Compare the sparking ef-ficiency of the cleaned and gappedplug with a new plug. Replace theplug if it fails to meet 70% of thenew plug performance.

Test the plugs for compressionleakage at the insulator seal. Apply acoating of oil to the shoulder of theplug where the insulator projectsthrough the shell, and to the top ofthe plug, where the center electrodeand terminal project from the insula-tor. Place the spark plug under pres-sure with the tester's high tensionwire removed from the spark plug.Leakage is indicated by air bubblingthrough the oil. If the test indicatescompression leakage, replace theplug. If the plug is satisfactory, wipeit clean.

2. Connect the green lead to thedistributor terminal of the coil.

3. Remove the No.1 plug wirefrom the distributor cap; place theblue pickup in the cap, and place theplug wire in the pickup.

4. On the RE-27-55 tester, con-nect the black lead to a good ground.

5. Clip the red pickup over thecoil-to-distributor high tension wire.

6. If the engine timing is to bechecked, p1ug the timing light intoits socket.

The following steps pertain to theRE-881 tester only.

7. Disconnect the battery positiveand negative cables at the battery.

8. Install the battery adapter onthe positive battery post.

9. Connect the battery positivecable to the battery adapter.

10. Connect the shunt spade ter-minal and the yellow lead to the bat-tery cable post on the battery adapt-er.

Ignition TimingIncorrect ignition timing can be

caused by:1. Timing incorrectly adjusted.2. Distributor bushing and! or

shaft worn, or a bent distributorshaft.

3. Defective vacuum advance sys-tem.

4. Defective centrifugal advancesystem.

IGNITION SYSTEM TESTS-ROTUNDA OSCILLOSCOPETESTERS

The following is a complete step-by-step procedure for connecting thescope, checking the ignition systemprimary and secondary circuits andchecking the engine dynamic com-pression (RE-881 only).

The primary and secondary super-imposed pattern checks can be per-formed with the engine cranking.This allows the dwell, coil and con-denser to be checked if the enginewill not start.

11. Connect the shunt to theadapter.

12. Connect the battery negativecable to the battery negative termi-nal and connect the black lead to thebattery negative terminal.

13. Turn the ground polarityswitch to the minus position. Turnthe VOLTS switch to the 20-volt po-sition.

POINT RESISTANCE TEST-RE-881 TESTER

This test checks the voltage dropfrom the distributor terminal of thecoil, through the primary wire andthe breaker points and to ground.

1. Remove and ground the hightension wire from the center of thedistributor.

2. Depress the VOLT AMP push-button and turn the VOLTS switchto the PT. RES. position.

3. Disconnect the brown wire (Iterminal) and the red and blue wire(S terminal) at the starter relay. In-stall an auxiliary starter switch be-tween the battery and S terminals ofthe starter relay. With the ignitionswitch ON, tap the auxiliary starterswitch until the lowest voltmeterreading is obtained.

4. Depress the PT. RES. push-button.

5. The voltmeter pointer shouldread in the 12V black, PT. RES. area.If it doesn't, check for improperbreaker point spring tension, a looseor defective primary or ground wire

Distributor CapClean and inspect the distributor

cap by following the procedure underCleaning and Inspection (Section 3 ofthis part).

RotorClean and inspect the rotor by fol-

lowing the procedure under Cleaningand Inspection (Section 3 of thispart).

Secondary (High Tension)WiresThe secondary wires include the

wires connecting the distributor capto the spark plugs and the wire con-necting the center terminal of thedistributor cap to the center terminalof the ignition coil.

Clean and inspect the secondarywiring by following the procedureQnder Cleaning and Inspection (Sec-tion 3 of this part).

These wires are the radio resist-ance-type which filter out the highfrequency electrical impulses thatare the source of ignition noise inter-ference. The resistance of each wireshould not exceed 7000 ohms perfoot.

When checking the resistance ofthe wires or setting ignition timing,do not puncture the wires with aprobe. The probe may cause a sep-aration in the conductor.

When removing the wires from thespark plugs, grasp and twist themoulded cap, then pull the cap offthe spark plug. Do not pull on thewire because the wire connection in-side the cap may become separatedor the insulator seal may be dam-aged.

To check the spark intensity at thespark plugs, proceed as follows:

1. Disconnect a spark plug wire.Check the spark intensity of one wireat a time.

2. Install a terminal adapter in theterminal of the wire to be checked.Hold the adapter approximately 3/16-inch from the exhaust manifold andcrank the engine, using a remotestarter switch. The spark should jumpthe gap regularly.

3. If the spark intensity of all thewires is satisfactory, the coil, con-denser, rotor, distributor cap and thesecondary wires are probably satis-factory.

If the spark is good at only somewires, check the resistance of thefaulty leads.

If the spark is equal at all wires,

TEST CONNECTIONS-RE-27-SS,AND RE-881

The test connections for the RE-27-55 tester are shown in Fig. 7 andthe test connections for the RE-881tester are shown in Fig. 8.

1. With the tester turned off, plug

PART 9-1 GENERAL IGNITION SYSTEM SERVICE 9-5

the engine to see if the timing ad-vances.

ffi

Red

Slack (GND

DISTRIBUTO~ '

TERMINAL\. G.reen

L~TO BATTERY

ENGINEBLOCK

tJ

-.-/'---' NO.1 SPARK ~UG V-

81991-C

FIG. 7 -Rotunda RE.27.55 Test Connections

or for burned or pitted points.6. Connect the high tension wire

to the distributor.7. Turn the ignition switch OFF

and turn the VOLTS switch to the20V position.

8. Remove the auxiliary starterswitch from the starter relay andconnect the brown wire and the redand blue wire to the starter relay.

RE-881 Tester1. Turn the RPM selector to the

800 position.1. Depress the ADVANCE TIM-

ING pushbutton.3. Start the engine and allow it to

warm up.4. Operate the engine at the speci-

fied idle rpm.5. Point the timing light toward

the timing pointer and turn the AD-VANCE control until the TDC marklines up with the pointer. The IGNI-TION ADVANCE scale of theVOLTS meter will indicate the ini-tial timing. If the initial timing is in-correct, loosen the distributor hold-down bolt and rotate the distributoruntil the desired timing is obtained.Tighten the distributor hold-downbolt and check the timing again incase the timing changed while thedistributor hold-down bolt was beingtightened.

6. Connect the distributor vacuumline (if so equipped).

7. Turn the RPM switch to the8000 position and adjust the enginespeed to 2000 rpm.

8. Point the timing light towardthe timing pointer and turn the AD-VANCE control until the TDC marklines up with the pointer. The IGNI-TION ADVANCE scale of theVOLTS meter will indicate the totalignition advance for 2000 rpm. Thetotal ignition advance should be thesum of the initial ignition timing,twice the centrifugal advance at 1000distributor rpm and twice the maxi-mum vacuum advance. If it isn't, thedistributor advance should bechecked on a distributor tester.

PRIMARY CIRCUITSUPERIMPOSED P A TfERN

This pattern shows the individualfiring patterns as seen by the primarycircuit. The individual firing patternsare superimposed to give the appear-ance of one firing pattern.

The primary circuit superimposedpattern will indicate incorrect batterypolarity, incorrect dwell angle, ex-cessive primary circuit resistance,partially shorted condenser, unevendistributor cam lobes, bent distri-butor shaft or worn distributor bush-ings.

IGNITION TIMINGThe following procedure checks

the initial ignition timing and the ig-nition advance mechanism.

Section 2 of this part gives the ig-nition timing mark locations.

Disconnect the distributor vacuumline (if so equipped). Clean and markthe desired timing mark if using theRE-27-55 tester or the TDC timingmark if using the RE-881 tester.

RE-27-55 Tester1. Start the engine and allow it to

warm up.2. Turn the TEST SELECTOR to

the TIMING LIGHT position.3. Operate the engine at the spec-

ified idle rpm and point the timinglight toward the pointer. The desiredtiming mark should line up with thepointer. If it doesn't, loosen the dis-tributor hold-down bolt and rotatethe distributor until the mark lines upwith the pointer. Now tighten thehold down bolt and check the timingagain in case the timing changedwhile the distributor hold-down boltwas being tightened.

4. Connect the distributor vacuumline (if so equipped).

5. With the timing light pointedtowards the timing marks, accelerate

Procedure

RE-27-55 Tester1. With the engine running at

- +..".e ","-8 "'"

,Red

~ ':0;' ~SHUNT

Black

Green

~BATTERY

CABLEBATTERY

, -DIST~1JTDR TERMINAL\'1'. .

\iTERYPOST AOAPTER

~ 62280.6

FIG. a-Rotunda RE-881 Test Connections

1000 rpm, turn the TEST SELEC- scope screen.TOR switch to the PRI. position. 4. Adjust the EXPAND control so

2. Adjust the PARADE control to that the right end of the pattern is atposition the left end of the pattern at the 6-cyl 0° dwell mark on the scopethe 6-cyl 60° dwell mark on the screen.scope screen.

3. Adjust the EXPAND controlso that the right end of the pattern isat the 6 cyl 0° dwell mark on thescope screen.

RE-881 Tester1. Turn the RPM selector to the

1600 rpm position. Start the engineand adjust it to 1000 rpm.

2. Depress the PRI. pushbutton onthe console panel.

3. Adjust the PARADE control toposition the left end of the patternat the 6-cyl 60° dwell mark on the

ResultsA normal test pattern is shown in

Fig. 9. Point A indicates the sparkplug line which is the time when thepoints open. At B, the coil energy isused up sufficiently so that the plugno longer fires and only the energystored in the breaker point condenserremains. The coil/ condenser oscilla-tion which is indicated in the patternbetween Band C is completely usedup at C which is the points closemark. The portion of the pattern be-tween C and D is the points close

time, which is cam angle or dwelltime. At D, the points again openand the firing cycle repeats.

If points A and C are below the 0line, the battery polarity is incorrect.This could be caused by a battery thatis either installed incorrectly or im-properly charged, causing a polarityreversal.

If the firing line is not below the0 horizontal line and there are nooscillations at point C, there is anopen circuit at the coil high tensiontower. This could be caused by abroken wire inside the coil tower, ora broken center contact on the dis-tributor rotor.

If the dwell time is too long orshort, the breaker points are incor-rectly set (the larger the gap, thesmaller the dwell).

If point A is at a reduced height,and the distance to B is short or non-existent, there is a high resistance inthe coil primary circuit. This couldbe caused by a fouled plug, defectiveignition switch, or a bad wire or con-nection. If the scope pattern is stillthe same after the above ignitionparts have been checked and provensatisfactory, run the 15 KV test tocheck for a gasket leak or a lean fuelmixture.

If point A is at a greatly reducedheight and there are no oscillationsat point B, the condenser is partiallyshorted.

If there is a variation of more than30 at point C, the cam lobes are un-even, the distributor shaft is bent, orthe distributor bushings are worn.

SECONDARY CIRCUITSUPERIMPOSED P A TfERN

This pattern shows the individualfiring patterns as seen by the second-ary circuit. The individual firing pat-terns are superimposed to give the

the distributor cap terminal or aspark plug wire, shorted or improper-ly adjusted spark plugs, partiallyshorted coil primary windings or anincorrect idle fuel mixture.

appearance of one firing pattern.The secondary circuit superim-

posed pattern will indicate arcingbreaker points, defective coil or coilhigh tension wire, excessive resistancein the distributor cap, rotor, second-ary wiring or spark plugs or a looseconnection in the primary circuit.

The ignition system, as seen by thesecondary circuit, can be furtherchecked by checking the 15 KV and30KV patterns.

Procedure

RE-27-55 Tester1. With the engine operating at

1000 rpm, turn the test selectorswitch to the 15 KV position.

2. Adjust the PARADE controlso that the left end of the pattern isat the 6-cyl 60° dwell mark on thescope screen.

3. Adjust the EXPAND controlso that the right end of the pattern isat the 6-cyl 0° dwell mark on thescope screen (Fig. 11).

Procedure

RE-27-55 Tester1. With the engine running at

lOOO rpm, turn the TEST SELEC-TOR switch to the SEC. position.

2. Adjust the PARADE controlso that the left end of the pattern isat the 6-cyl 60° dwell mark on thescope screen.

3. Adjust the EXPAND control sothat the right end of the pattern is atthe 6-cyl 0° dwell mark on the scopescreen.

RE-881 Tester. The procedure isthe same as the procedure for theprimary (superimposed) except, theSEC. pushbutton is depressed insteadof the PRI. pushbutton.

ResultsA normal test pattern is shown in

Fig. 10.

. . B1995-A

FIG. 1 a-Normal SuperimposedSecondary Circuit Pattern

Point A is the points open time.The height of the pattern at point Aindicates the high tension voltage re-quired to overcome the spark pluggap resistance.

Point B is the plug firing line. No-tice that this portion of the pattern isquite thick. Remember that this pat-tern is actually 6 or 8 firing patternssuperimposed one on top of the oth-er. This increase in thickness of thepattern at B is caused by slight vari-

ations in the plug gap, distributorrotor gap and slight differences in theresistance of the individual spark plugcircuits.

The pattern area between pointsC and D shows the coil/condenseroscillations to be correct. No pointbounce at D indicates correct break-er point spring tension.

The few so-called damped oscilla-tions appearing at D are normal andare caused by the surge of currentthrough the coil primary windingwhen the breaker points first close.

This current levels off and de-creases slightly toward the pointsopen position at E as indicated by theslight downward slope of the curveat about the 8-cyl 15° mark on thecam angle scale.

To observe the coil/ condenser os-cillations and the damped oscillationsat D in the greater detail, adjust theexpand control so that the patternarea between points C and D nearlyfills the screen.

If there is erratic action at pointsC and D, and there is a blotch abovepoint E, the breaker points areburned or badly pitted.

If there are no condenser oscilla-tions between C and D and nodamped oscillations at point D, thereare shorted primary windings in thecoil.

If the line at B is sloping down-ward greatly from A to C (resistorplugs will cause a slight slope), thereis a high resistance in the spark plugwires, distributor cap or rotor. Ifthe line at B is sloping upward, thereis a high resistance in the spark plugs.If some of the firing patterns are cor-rect and others are sloping incorrect-ly, perform a 15 KV pattern checkto find out which cylinder has the de-fective part.

If the dwell line between points Dand E is not the smooth line shown,there is a loose connection in the pri-mary circuit. Check the primary cir-cuit for loose connections, damagedwires or a defective starter switch.

SECONDARY CIRCUIT 15 KVP A TfERN

This pattern shows the individualfiring patterns as seen by the second-ary circuit. The individual firing pat-terns are paraded from left to rightin order of firing order.

The secondary circuit 15 KV pat-tern will indicate weak breaker pointspring tension, improper breakerpoint contact, incorrect condensercapacitance, excessive resistance in

B1996-A

FIG. 11-Normal SecondaryCircuit 15 KV Paltern

RE-881 Tester1. With the RPM selector at the

1600 position and the engine oper-ating at 1000 rpm, depress the 15KV pushbutton.

2. Adjust the PARADE control sothat the left end of the pattern is atthe 6-cyl 60° dwell mark on thescope screen.


ResultsA normal eight cylinder engine 15

KV pattern is shown in Fig. 11. Thesix cylinder pattern would have sixsimilar images. The spark plug line(A) for the No.1 spark plug is onthe extreme right hand side of thescreen. The remainder of the No.1firing pattern is on the left side of thescreen. The remainder of the pat-terns are shown from left to right intheir firing order.

With the exception of the No.1spark plug line (which should beshorter than the others), the patterns


spark plug wire at the spark plug. Ifa plug firing line shows up on thescope for that cylinder, check theplug wire, rotor and distributor capfor bad insulation.

DYNAMIC COMPRESSIONTEST-RE-881 TESTER

1600 position and the engine oper-ating at 600 rpm, depress the 30 KVpushbutton.

2. Adjust the PARADE control sothat the 6-cyl 60° dwell mark onthe scope screen.


Procedure

1. Turn the RPM selector to the1600 position and depress the DY-NAMIC COMPRESSION pushbut-ton.

2. Adjust the engine to 1500 rpm.3. Adjust the EXPAND and PA-

RADE controls so that the six pat-terns (6-cyl) or eight patterns (8-cyl) fill the scope screen dwell range.

4. Press and turn the BALANCETO LINE control to position theneedle on the DYNAMIC COM-PRESSION scale at the 0 mark.

5. The pattern indication as shownat 5 in Fig. 13 will appear at point A.

6. Turn the CYLINDER SELEC-TOR control clockwise from its OFFposition. As the switch is turnedclockwise, the pattern indication willmove to the right across the scope.

7. When the pattern indicationpasses through the firing pattern forcylinder number 5, the plug firingline will disappear (Fig. 13) and theengine will miss on the number 5 cyl-inder.

8. Observe the dynamic compres-sion meter reading for the number 5cylinder.

9. Continue to rotate the CYL-INDER SELECTOR control to du-plicate the above condition for eachcylinder in the system except numberone (last plug firing line).

10. Turn the CYLINDER SE-LECTOR control to its maximumclockwise rotation.

11. Turn the NO.1 CYL. switch0O.

12. Slowly turn the CYLINDERSELECTOR control counterclock-wise until the pattern shown in Fig.14 is obtained.

13. Observe the dynamic compres-sion meter reading for the number Icylinder.NOTE: If the engine rpm shouldchange from 1500 rpm, set the speedback to 1500 rpm and repeat step 5.

ResultsThe readings obtained are relative

readings. However, if the enginecompression and firing conditions arenormal, the readings for all cylinderswill be approximately the same.

should be similar. If one of the pat-terns differs from the others, adjustthe expand and parade controls untilthat pattern fills the screen in thesame manner as in the secondarytest (Fig. 10).

The following list of symptoms willrefer to Fig. 10.

If there is a fluctuation at point C,the points may have incorrect springtension.

The condenser oscillation signalfrom C to D should diminish to astraight line at D. If it doesn't, thecondenser capacitance is incorrect.

If the points open line (A) ishigher than the rest and the plug fir-ing line (B) is sloped downward atan unusually large slope, there is ex-cessive resistance in the high tensionwire to that cylinder or in the distri-butor cap.

If the points open line (A) is lowand the firing line (B) is long andnearly straight, the spark plug isshorted out.

If the points open line (A) is lowand the firing line (B) is long andwide, the spark plug gap is out ofadjustment.

If there are no oscillations atpoints C or D, the coil primary wind-ings are partially shorted.

If all of the points open lines (A)are at varied heights, check the idleadjustment of the carburetor (al-ways adjust the idle mixture on therich side).

SECONDARY CIRCUIT 30 KVPATTERN

This pattern is like the 15 KV pat-tern with the exception of the height.The height has been reduced to al-low for checking the coil reserve.

The secondary circuit 30 KV pat-tern will indicate excessive resistancein the plugs, insufficient coil reservevoltage or leakage at the rotor, dis-tributor cap or spark plug wire.

Procedure

RE-27-55 Tester1. With the engine running at 600

rpm, turn the test selector switch tothe 30.KV position.

2. Adjust the PARADE control sothat the left end of the pattern is atthe 6-cyl 60° dwell mark on thescope screen.

3. Adjust the EXPAND control sothat the right end of the pattern is atthe 6-cyl 0° dwell mark on the scopescreen (Fig. 12).

RE-881 Tester1. With the RPM selector at the

ResultsA normal eight cylinder engine 30

KV pattern is shown in Fig. 12. Thesix cylinder pattern would have sixsimilar images. The spark plug line(A) for the No.1 spark plug is onthe extreme right hand side of thescreen. The remainder of the No.1firing pattern is on the left side of thescreen. The remainder of the pat-terns are shown from left to right intheir firing order.

Notice the average height of thesolid part of the points open line. In-crease the speed of the engine andnotice the height of the dotted lines.The difference is the required ignitionoutput under load. The maximumshould be between 13.5 and 15 KV.

If the maximum for one or moreof the plugs is above 15 KV, checkthe complete circuit(s) of the plug(s)for any trouble that would cause re-sistance. If the maximum does notincrease during the increase in en-gine speed, check for a fouled or im-properly gapped spark plug or forvery low compression.

Remove the high tension wire atthe distributor cap for any plug ex-cept No.1. Notice the change be-tween the average points open lineand the points open line of the cylin-der with the high tension wire re-moved. This height difference is thecoil reserve. The coil reserve shouldbe at least 20 KV. If it is less than 20KV, replace the coil.

Remove and do not ground one

PART 9-1 GENERAL IGNITION SYSTEM SERVICE 9-9

FIG. 13-Typical Dynamic Compression Pattern-All Except No.1 Cylinder

If the readings are not within 3divisions of each other, the cylin-der(s) with the low reading(s) arenot operating as efficiently as theother cylinders.

A cylinder (or cylinders) that isnot operating efficiently indicatesone or more of the following causes:

Low Compression caused by wornpiston rings, leaking valves, leakingcylinder head gasket and/ or dam-aged piston or rings.

Intake Vacuum Leak caused byleaking manifold, carburetor or car-buretor spacer gaskets.

Malfunctioning Crankcase Venti-lation Regulator Valve.

Carburetor Air Cleaner Restricted.

DISTRIBUTOR CHECKS

DISTRIBUTOR GEARBACKLASH-LOADOMA TICDISTRmUTOR

The distributor gear backlash cannot be accurately checked on the dualadvance or centrifugal advance dis-tributor.

1. Mount a dial indicator on thedistributor so that the indicator pointrests on the rotor, S/s -inch from thecenter.

2. Turn the rotor as far as it willgo and set the indicator on zero.

3. Turn the rotor in the oppositedirection and note the reading on thedial indicator. This is the backlash.

4. The backlash should be 0.003to 0.005 inch. If the backlash is notto specifications, it indicates an incor-rect number of teeth on the distrib-utor or camshaft gear, or excessivelyworn gears.

DISTRmUTORSHAFrEND PLAY

If the shaft end play is not to spec-ifications, check the location of thegear on the shaft (loadomatic dis-tributor), or the distributor shaft col-lar (dual advance or centrifugal ad-vance distributor).

B2577.A

Loadomatic DistributorThe shaft end play can be checked

with the distributor installed on theengine.

1. Mount a dial indicator on thedistributor so that the indicator tiprests on the top of the distributorshaft.

2. Push the shaft down as far as itwill go and set the dial indicator onzero.

3. Pull the distributor shaft up-ward as far as it will go and read theFIG. 14-Typical Dynamic Compression Pattern-No.1 Cylinder


end play. The end play should bewithin specifications with the distri-butor removed or installed.

Dual Advance and CentrifugalAdvance Distributor1. Remove the distributor from

the engine.2. Place the distributor in the hold-

ing tool and clamp it in a vise withthe gear end up.

3. Push the distributor shaft up-ward as far as it will go, and checkthe end play with a feeler gaugeplaced between the collar and the dis-tributor base. The end play should bewithin the specified limits.

5. Adjust the speed control to varythe distributor speed between 400and 4000 engine rpm, or at the maxi-mum speed of the engine on whichthe distributor is used. Erratic or thinfaint flashes of light preceding theregular flashes as the speed of rota-tion is increased can be due to weakbreaker arm spring tension or bind-ing of the breaker arm on the pivotpin.

6. Operate the distributor at ap-proximately 2500 engine rpm andmove the protractor scale so that thezero degree mark on the scale is op-posite one of the neon flashes. Thebalance of all the flashes should comewithin 10, plus or minus, evenlyaround the protractor scale. A varia-tion larger than 10 or erratic or wan-dering flashes may be caused by aworn cam or distributor shaft or abent distributor shaft.

DISTRIBUTOR TESTS-ROTUNDA RE-27-44 DWELLTESTER

3. Disconnect the brown wire (Iterminal) and the red and blue wire(S terminal) from the starter relay.

4. Loosen the breaker point as-sembly retaining screw near thebreaker point contacts.

5. With the ignition on, crank theengine with an auxiliary starterswitch connected between the batteryand S terminals of the starter relayand adjust the gap to specifications.

6. Release the auxiliary starterswitch and tighten the breaker pointassembly retaining screw.

7. Since the adjustment may havechanged when the retaining screwwas tightened, crank the engine againwith the auxiliary starter switch andcheck the dwell.

On dual-point distributors, whenthe combined dwell has been set tospecifications, the individual dwellsettings should be checked. To checkthe individual dwell settings, blockone set of points open with a piece ofinsulating material and check thedwell of the other set. The individualdwell settings should be the same.

DWELL ANGLE

TEST CONNECTIONS1. Connect the red lead to the dis-

tributor terminal of the coil.2. Connect the black lead to a

good ground on the engine.

DISTRIBUTOR TESTS-ROTUNDA RE-236DISTRIBUTOR TESTER

Single Point Distributors1. Turn the OFF, SET, CAM,

SYNC. switch to the CAM position.Operate the distributor at about 1000rpm.

2. Adjust the breaker point gapuntil the dwell angle is to specifica-tions.

Dual Point Distributors1. Turn the OFF, SET, CAM,

SYNC. switch to the CAM position.Operate the distributor at about 1000rpm.

2. Adjust the breaker points untilthe combined dwell is to specifica-tions and the individual dwells arethe same.

The individual dwell settings arechecked by isolating one set of pointsfrom the circuit. This is done byplacing a piece of insulating materialbetween the contacts.

BREAKER PLATE WEARA worn breaker plate on the load-

omatic or dual advance distributorswill cause the breaker point gap andcontact dwell to change as enginespeed and load conditions are varied.

On the loadomatic distributor,there should not be over a 3 ° varia-

tion in dwell between engine idlespeed and 2500 rpm. If the contactdwell changes more than 3°, the plateand bushing should be replaced.

On the dual advance distributor,adjust the test set to 0° advance, 0inches vacuum, and 1000 rpm. Ad-just the dwell angle to 26°. Apply

DWELL ANGLE CHECK1. Connect the tester.2. Turn the test control knob to

the set position.3. Adjust the set control knob un-

til the needle on the dwell meter linesup with the set line.

4. Start the engine and let it idle.5. Turn the test control knob to

the 8 CYL position for eight cylinderengines or to the 6 CYL position for6 cylinder engines.

6. Read the dwell angle on thedwell meter and compare the readingto specifications.

7. Turn off the engine.8. If the dwell angle was below the

specified amount, the breaker pointgap is too large. If the dwell anglewas above the specified amount, thebreaker point gap is too small.

On dual point distributors, the gapsof both breaker point assembliesshould be the same.

If the dwell is to specifications,turn the test selector knob to theOFF position and disconnect the test-er leads.

DWELL ANGLEADJUSTMENT

If the dwell angle is not withinspecifications, proceed as follows:

1. Remove the coil high tensionlead from the distributor and groundit.

MOUNTING DISTRmUTOR1. Adjust the distributor support

arm in relation to the distributorshaft length.

2. Set the distributor in the sup-port arm and enter the lower end ofthe distributor shaft in the Syncro-graph chuck.

3. Tighten the chuck on the dis-tributor shaft, using the wrench lo-cated near the support arm column.

4. Align the distributor shaft byshifting the support arm and distrib-utor, and tighten the clamp screw.

5. Clamp the distributor securelyin the distributor support arm clampso that it will not turn in its mount-ing.

6. Connect the synchrograph testlead to the primary wire of the dis-tributor.

MECHANICAL OPERATIONS1. Turn the OFF, SET, CAM,

SYNC. switch to the SET position.2. Adjust the SET TACH control

so the tachometer pointer is on theSET line.

3. Turn the OFF, SET, CAM,SYNC. switch to the SYNC. position.

4. Turn the MOTOR switch to theLEFT for 8 cylinder cars or to theRIGHT for 6 cylinder cars.

2. Remove the distributor capand place it out of the way.

PART 9-1 - GENERAL IGNITION SYSTEM SERVICE 9-11

~... -. ,-CONTROLS LOW

VACUUM ADVANCECONTRO

VACUUM Screwdriver 82010.8

FIG. 16-Centrifugal Advance

Adjustment

mum advance point again.4. Operate the distributor at the

specified rpm to give an advance justbelow the maximum. If this advanceis not to specifications, stop the dis-tributor and bend the other springbracket to give the correct advance.

S. Check the advance at all rpmsettings listed in the specifications.Operate the distributor both up anddown the rpm range.

Vacuum Advance1. Connect the test set vacuum

line to the fitting on the diaphragm.2. Set the test set to 0° advance,

0 vacuum, and at 1000 rpm.3. Check the advance at the first

vacuum setting given in the specifi-cations.

4. If the advance is incorrect,change the calibration washers be-tween the vacuum chamber springand nut (Fig. 17). After installing orremoving the washers, position thegasket in place and tighten the nut.The addition of a washer will de-crease advance and the removal of awasher will increase advance.

S. After one vacuum setting hasbeen adjusted, the others should be

FIG. 15-Spark AdvanceAdjustment

er's vacuum line to the vacuum fittingon the diaphragm without changingany of the adjustments. The maxi-mum gauge reading should not beless than it was above. If it is less, thediaphragm is leaking and should bereplaced.

Dual Advance Distributor1. Check the contact dwell. If the

contact dwell is not within specifica-tions, adjust the breaker points.

2. Check the breaker arm springtension and adjust it, if necessary.

The dual advance distributor hastwo independently operated spark ad-vance systems. Each system is ad-justed separately. Adjust the centrif-ugal advance before adjusting thevacuum advance.

SPACING WASHERS 82011.8

FIG.- 17-Vacuum AdvanceAdjustment

vacuum to the distributor diaphragmand increase it very slowly while ob-serving the indicated dwell angle. Themaximum dwell angle variationshould not exceed 6° when goingfrom zero to maximum vacuum atconstant rpm. If the dwell angle vari-ation exceeds this limit, there is ex-cessive wear at the stationary sub-plate pin or the diaphragm rod isbent or distorted.

DISTRIBUTOR SPARKADVANCE

The spark advance is checked todetermine if the ignition timing ad-vances in proper relation to enginespeed and load.

Loadomatic Distributor1. Check the breaker point con-

tact dwell. If the contact dwell is notwithin specifications, adjust thebreaker points.

2. Check the breaker arm springtension. Adjust if necessary.

3. Adjust the test set to 0° ad-vance, 0 inch vacuum and the initialrpm setting listed in the specifica-tions.

4. Check the operation of the vac-uum advance at the lowest and high-est vacuum and rpm settings given inthe specifications.

If the spark advance is not withinthe limits under low vacuum, theprimary spring adjustment is at fault.If the spark advance is not within thelimits under high vacuum, the sec-ondary spring adjustment is at fault.

To adjust the spark advance, re-lease the tension on the retard springsby turning the adjusting posts as re-quired (Fig. 15). Adjust the primaryspring (spring closest to the vacuumchamber) first, for the low vacuumsettings. Adjust the secondary springlast, for the high vacuum settings. Asa final check, check the advancethroughout the entire range.

If it is impossible to adjust bothsprings to give the correct spark ad-vance throughout the range, one orboth springs should be replaced andthe spark advance readjusted.

If the advance characteristics stillcannot be brought within specifica-tions, check the diaphragm assemblyas follows:

Adjust the vacuum pressure of thedistributor tester to its maximum po-sition. Hold your hand over the endof the tester's vacuum hose and notethe maximum reading obtained. Donot exceed 25 inches Hg.

If the maximum reading is 25inches Hg or less, connect the test-

Centrifugal Advance1. Operate the distributor in the

direction of rotation (counterclock-wise) and adjust the speed to the ini-tial rpm setting listed in the specifi-cations. Move the protractor scaleso that one of the flashes lines upwith the zero degree mark.

2. Slowly increase the rpm to thesetting specified for the first advancereading listed in the specifications.

If the correct advance is not indi-cated at this rpm, stop the distribu-tor and bend one spring adjustmentbracket to change its tension (Fig.16). Bend the adjustment bracketaway from the distributor shaft todecrease advance (increase springtension) and toward the shaft to in-crease advance (decrease spring ten-sion). After the adjustment is made,identify the bracket.

3. After an adjustment has beenmade to one spring, check the mini-

., ~. ~lS HIGHADVANCE

B2137.C


POINT RES. position.2. Revolve the chuck by hand un-

til the distributor breaker points areclosed.

3. The meter pointer on the camangle meter should read in the OKzone at the left side of the meterscale. If the meter pointer does notfall in the OK zone, there is excessiveresistance caused by a faulty contactacross the distributor points, a faultyprimary lead, or a poorly groundedbase plate. A faulty contact acrossthe distributor points indicates im-proper spring tension or burned orpitted points.

---Screwdriver

82326-8

FIG. 18-Dual PointDistributor CentrifugalAdvance Adjustment

bracket to give the correct advance.8. Check the advance at all rpm

settings listed in the specifications.Operate the distributor both up anddown the rpm range.

Lack of synchronization, excessivecam wear, worn bearings, or weakbreaker arm spring tension causingcontact point chatter are all disclosedby uneven or intermittent flashesaround the protractor scale.

INSULATION AND LEAKAGE1. Turn the test selector to the

cam angle position and revolve thechuck by hand until the distributorbreaker contacts are open.

2. The cam angle meter shouldshow a zero reading. If a zero read-ing is not obtained, a short circuit toground exists.

A short could be caused by poorprimary lead wire insulation, ashorted condenser, or a short be-tween the breaker arm and breakerplate.

MECHANICAL OPERATION1. Turn the test selector to the

SYNCHRO. position and check tomake sure the drive chuck is securelytightened on the distributor shaft.

2. Turn the motor control switchto the left for an eight cylinder caror to the right for a six cylinder car.

If it is necessary to reverse the ro-tation of the drive motor, turn themotor control switch to the OFF po-sition and allow the chuck to cometo a complete stop before reversingthe switch.

3. Adjust the rpm control to varythe distributor speed between 400and 4000 engine rpm or at the maxi-mum speed of the engine on whichthe distributor is used. Erratic or thinfaint flashes of light preceding theregular flashes as the speed of rota-tion is increased can be due to weakbreaker arm spring tension or bind-ing of the breaker arm on the pivotpin.

4. Operate the distributor at ap-proximately 2500 engine rpm.

S. Move the protractor scale withthe adjustment control so that thezero degree mark on the scale is op-posite one of the neon flashes. Thebalance of all the flashes should comewithin 10, plus or minus, evenlyaround the protractor scale. A varia-tion larger than 10 or erratic or wan-

DISTRIBUTOR TESTS-ROTUNDA RE-1416DiSTRIBUTOR TESTER

MOUNTING DISTRIBUTOR1. Clamp the distributor securely

in the distributor support arm clampso that it will not turn in its mount-ing.

2. Loosen the hand-operated lock-ing screw on the side of the distribu-tor support arm and adjust the sup-port arm column up or down byturning the crank on the knob at thetop of the column until the distribu-tor shaft or adapter shaft can be se-curely fastened in the driving chuck.

3. Securely tighten the drivechuck to the distributor drive shaftby means of the chuck key, attachedby a chain to the Syncrograph.

4. Rotate the drive chuck by handto make sure the distributor shaftturns freely and then tighten thelocking screw on the distributor sup-port arm.

5. Connect the Syncrogr,aph testlead to the primary lead wire'ofthedistributor.

checked. Do not change the originalrpm setting when going to a differentvacuum setting. If the other settingsare not within limits, there is incor-rect spring tension, leakage in thevacuum chamber and/ or line, or thewrong fibre stop has been installedin the vacuum chamber of the dia-phragm housing.

To check the diaphragm for leak-age:

Remove the vacuum line from thedistributor. Adjust the vacuum pres-sure of a distributor tester to itsmaximum position. Hold your handover the end of the tester's vacuumhose and note the maximum readingobtained. Do not exceed 25 inchesHg.

If the maximum reading is 25inches Hg or less, connect the tester'svacuum line to the vacuum fitting onthe diaphragm without changing anyof the adjustments. The maximumgauge reading should not be less thanit was above. If it is less, the dia-phragm is leaking and should be re-placed.

Centrifugal Advance Distributor1. On a high performance centrif-

ugal advance distributor, check thegap of the breaker point assembliesor the combined dwell.

2. Check the breaker arm springtension and adjust it if necessary.

3. Turn the OFF, SET, CAM,SYNC. switch to SYNC. position.

4. Operate the distributor in thedirection of rotation (counterclock-wise) and adjust the speed to the in-itial rpm setting listed in the specifi-cations. Move the protractor scale sothat one of the flashes lines up withthe zero degree mark.



6. After an adjustment has beenmade to one spring, check the mini-mum advance point again.

7. Operate the distributor at thespecified rpm to give an advance justbelow the maximum. If this advanceis not to specifications, stop the dis-tributor and bend the other spring

BREAKER POINTRESISTANCE

1. Turn the test selector to

9-13PART 9.1 GENERAL IGNITION SYSTEM SERVICE

Dual Advance Distributor1. Check the contact dwell. If the

contact dwell is not within specifica-tions, adjust the breaker points.


The dual advance distributor hastwo independently operated sparkadvance systems. Each system is ad-justed separately. Adjust the centrif-ugal advance before adjusting thevacuum advance.

dering flashes may be caused by aworn cam or distributor shaft or abent distributor shaft.

DWELL ANGLE

Single Point Distributor1. Turn the cylinder selector to

the figure corresponding to the num-ber of lobes on the cam of the dis-tributor being tested.

2. Turn the test selector switch tothe cam angle position and operatethe distributor at approximately1000 engine rpm.

3. Adjust the distributor breakerpoint gap to the dwell angle shown inthe specifications.

Dual Point Distributor1. Follow steps 1 and 2 under

"Single Point Distributor."2. Adjust the breaker points until

the combined dwell is to specifica-tions and the individual dwell settingsare the same.

The individual dwell settings arechecked by isolating one set of pointsfrom the circuit. This is done byplacing a piece of insulating materialbetween the contacts.

Centrifugal Advance1. Operate the distributor in the

direction of rotation (counterclock-wise) and adjust the speed to the in-itial rpm setting listed in the specifi-cations. Move the protractor scaleso that one of the flashes lines upwith the zero degree mark.




4. Operate the distributor at thespecified rpm to give an advance justbelow the maximum. If this advanceis not to specifications, stop the dis-tributor and bend the other springbracket to give the correct advance.

5. Check the advance at all rpmsettings listed in the specifications.Operate the distributor both up anddown the rpm range.

BREAKER PLATE WEARA worn breaker plate on the load-

omatic or dual advance distributorswill cause the breaker point dwell tochange as engine speed and load con-ditions are varied.

On the loadomatic distributorthere should not be over a 3 ° varia-

tion in dwell between engine idlespeed and 2500 rpm. If the contactdwell changes more than 3°, theplate bushing should be replaced.

On the dual advance distributoradjust the test set to 0° advance, 0inches vacuum, and 1000 rpm. Ad-just the dwell angle to 26°. Applyvacuum to the distributor diaphragmand increase it very slowly while ob-serving the indicated dwell angle. Themaximum dwell angle variationshould not exceed 6° when goingfrom zero to maximum vacuum atconstant rpm. If the dwell angle var-iation exceeds this limit, there is ex-cessive wear at the stationary sub-plate pin or the diaphragm.

Loodomatic Distributor1. Check the breaker point con-

tact dwell. If the contact dwell isnot within specifications, adjust thebreaker points.

2. Check the breaker arm springtension. Adjust if necessary.

Attach the vacuum adapter fittingto the vacuum unit and attach thevacuum hose between the distributorvacuum control and the vacuum out-let located at the upper right of thefront panel. Check the zero setting ofthe vacuum gauge and, if necessary,adjust the small knob at the loweredge of the dial rim so that the vac-uum gauge hand rests on zero.

Turn the vacuum supply switch tothe ON position.

3. Adjust the test set to 0° ad-vance, 0 inch vacuum and the initialrpm setting listed in the specifications.

4. Check the operation of thevacuum advance at the lowest andhighest vacuum and rpm settingsgiven in the specifications.

If the spark advance is not withinthe limits under low vacuum, the pri-mary spring adjustment is at fault. Ifthe spark advance is not within thelimits under high vacuum, the sec-ondary spring adjustment is at fault.

To adjust the spark advance, re-lease the tension on the retard springsby turning the adjusting posts as re-quired (Fig. 15). Adjust the primaryspring (spring closest to the vacuumchamber) first, for the low vacuumsettings. Adjust the secondary springlast, for .the high vacuum settings. Asa final check, check the advancethroughout the entire range.

If it is impossible to adjust bothsprings to give the correct spark ad-vance throughout the range, one orboth springs should be replaced andthe spark advance readjusted. If theadvance characteristics still cannotbe brought within specifications,check the diaphragm assembly as fol-lows:

Adjust the vacuum pressure of adistributor tester to its maximum po-sition. Hold your hand over the endof the tester's vacuum hose and notethe maximum reading obtained. Donot exceed 25 inches Hg.

If the maximum reading is 25inches Hg or less, connect the tester'svacuull} line to the vacuum fitting onthe diaphragm without changing anyof the adjustments. The maximumgauge reading should not be less thanit was above. If it is less, the dia-phragm is leaking and should be re-nl"l'p,1

Vacuum Advance1. Connect the test set vacuum line

to the fitting on the diaphragm andturn the vacuum supply switch on.

2. Set the test set to 0° advance, 0vacuum, and at 1000 rpm.

3. Check the advance at the firstvacuum setting given in the specifica-tions.

4. If the advance is incorrect,change the calibration washers be-tween the vacuum chamber springand nut (Fig. 17). After installing orremoving the washers, position thegasket in place and tighten the nut.The addition of a washer will de-{'rea~e advance and the removal of a

DISTRIBUTOR SPARKADVANCE

The spark advance is checked todetermine if the ignition timing ad-vances in proper relation to engine~nppli "nli In,,1i

9-14 GROUP 9 -IGNITION SYSTEM

gauge reading should not be less thanit was above. If it is less, the dia-phragm is leaking and should be re-placed.

bracket to change its tension (Fig.18). Bend the adjustment bracketaway from the distributor shaft todecrease advances (increase springtension) and toward the shaft to in-crease advance (decrease spring ten-sion). After the adjustment is made,identify the bracket.


7. Operate the distributor at thespecified rpm to give an advance justbelow the maximum. If this advanceis not to specifications, stop the dis-tributor and bend the other springbracket to give the correct advance.

8. Check the advance at all rpmsettings listed in the specifications.Operate the distributor both up anddown the rpm range.

Lack of synchronization, excessivecam wear, worn bearings, or weakbreaker arm spring tension causingcontact point chatter are all disclosedby uneven or intermittent flashesaround the protractor scale.

Centrifugal Advance Distributor1. On a high performance centrif-

ugal advance distributor, check thecombined dwell. If it is not withinspecifications, adjust the gap.


3. Turn the test selector to theSYNCRO. position.

4. Operate the distributor in thedirection of rotation (counterclock-wise) and adjust the speed to the in-itial rpm setting listed in the specifi-cations. Move the protractor scale sothat one of the flashes lines up withthe zero degree mark.


If the correct advance is not indi-cated at this rpm, stop the distribu-tor and bend one spring adjustment

washer will increase advance.5. After one vacuum setting has

been adjusted, the others should bechecked. Do not change the originalrpm setting when going to a differentvacuum setting. If the other settingsare not within limits, it indicates in-correct spring tension, leakage inthe vacuum diaphragm and/ or line,or the wrong fiber stop has been in-stalled in the vacuum chamber of thediaphragm housing.

To check the diaphragm for leak-age:

Remove the vacuum line from thedistributor. Adjust the vacuum pres-sure of a distributor tester to itsmaximum position. Hold your handover the end of the tester's vacuumhose and note the maximum readingobtained. Do not exceed 25 inchesHg.

If the maximum reading is 25inches Hg or less, connect the tester'svacuum line to the vacuum fitting onthe diaphragm without changing anyof the adjustments. The maximum

COMMON ADJUSTMENTS AND REPAIRSBREAKER POINTS AND Dual Advance DistributorsCONDENSER

R Iemova1. Remove the distributor cap and

the rotor.2. Disconnect the primary and the

condenser wires from the breakerpoint assembly.

3. Remove the breaker point as-sembly and condenser retainingscrews. Lift the breaker point assem-bly and condenser out of the distribu-tor.

REPLACEMENT

Loadomatic Distributors

Removal

1. Remove the distributor cap androtor.

2. Disconnect the condenser- andprimary lead wires from the breakerpoint assembly.

3. Remove the breaker point as-sembly and condenser retainingscrews and lift the breaker point as-sembly and condenser out of the dis-tributor.

Installation

Installation1. Place the breaker point as-

sembly and the condenser in positionand install the retaining screws. Besure to place the ground wire underthe breaker point assembly screwfarthest from the breaker point con-tacts.

2. Align and adjust the breakerpoint assembly.

3. Connect the primary and con-denser wires to the breaker point as-sembly.

4. Install the rotor and the distri-butor cap.

2. Disconnect the primary lead,the jumper strap, and the condenserlead from the breaker point assem-blies.

3. Remove the retaining screwsfrom the breaker point assembliesand the condenser. Lift the breakerpoint assemblies and the condenserout of the distributor.

Installation1. Place the breaker point assem-

blies and the condenser in positionand install the retaining screws.

2. Align and adjust the breakerpoint assemblies.

3. Connect the primary lead, thejumper strap, and the condenser leadto the breaker point assemblies.

4. Install the rotor and the distrib-utor cap.

BREAKER POINTALIGNMENT

The vented-type breaker pointsmust be accurately aligned and strikesquarely in order to realize the fulladvantages provided by this designand assure normal breaker point life.Any misalignment of the breakerpoint surfaces will cause prematurewear, overheating and pitting.

1. Turn the cam so that the break-er points are closed and check thealignment of the points (Fig. 19).

1. Place the breaker point assem-bly.and condenser in: position on thebreaker plate and install the screws.Be sure that the ground wire is underthe breaker point assembly screwnearest the breaker point contacts.Align and adjust the breaker points.

2. Connect the primary and con-denser wires to the breaker point as-sembly.

3. Install the rotor and distributorcap.

Centrifugal Advance Distributor

Removal1. Remove the distributor cap and

the rotor.


Distributor Tests-Rotunda RE-27-55 Dwell Tester.

A scope or a dwell meter can beused to check the gap of used breakerpoints. Due to the roughness of usedpoints, it is not advisable to use afeeler gauge to check the gap.

To check and adjust the breakerpoints with a feeler gauge:

1. Check and adjust the breakerpoint alignment.

2. Rotate the distributor until therubbing block rests on the peak of acam lobe.

If the distributor is in the engineplace the rubbing block on the peakof the cam by proceeding as follows:

Disconnect the brown wire and thered and blue wire from the starter re-lay and, with the ignition switch off,crank the engine by using an auxiliarystarter switch between the S and bat-tery terminals of the starter relay.

Insert the correct blade of a cleanfeeler gauge between the breakerpoints (Fig. 21).

BREAKER POINT SPRINGTENSION ADJUSTMENT

Correct breaker point spring ten-sion is essential to proper engine op-eration and normal breaker pointlife. If the spring tension is too great,rapid wear of the breaker arm rub-bing block will result, causing thebreaker point gap to close up and re-tard the spark timing. If the springtension is too weak, the breaker armwill flutter at high engine rpm result-ing in an engine miss.

To check the spring tension oneither the pivot-type or the pivotlessbreaker points, place the hooked endof the spring tension gauge over themovable breaker point. Pull the gaugeat a right angle (90°) to the movablearm until the breaker points just startto open (Fig. 22). If the tension isnot within specifications, adjust thespring tension on the pivot-typepoints or replace the breaker pointassembly on the pivotless points.

Feeler GaugeToot-KD.111 or TK-419.A

Too/-KD.111 or TK.419.A

FIG. 22-Checking BreakerPoint Spring Tension

-~~

BEND STATIONARY BRACKET B2012-C

FIG. 20-Aligning Breaker

Points

3. After the breaker points havebeen properly aligned, adjust thebreaker point gap or dwell.

BREAKER POINTGAP ADJUSTMENT

A scope, a dwell meter, or a feelergauge can be used to check the gapof new breaker points.

FIG. 21-Adjusting NewBreaker Point Gap

Apply a light film of distributorcam lubricant (C4AZ-19D530-A) tothe cam when new points are in-stalled. Do not use engine oil to lu-bricate the distributor came

Set the ignition timing.If a scope or a dwell meter is used

to adjust new points, be sure thepoints are in proper alignment. Also,set the contact dwell to the low set-ting. New points must be set to thelow dwell as the rubbing block willwear down slightly while seating tothe cam.

To check and adjust the breakerpoints with a scope, refer to IgnitionSystem Tests-Rotunda OscilloscopeTesters.

To check and adjust the breakerpoints with a dwell meter, refer to

To adjust the spring tension (Fig.23):

1. Disconnect the primary or dis-tributor-transistor lead wire and thecondenser lead if so equipped, andthe jumper strap on the centrifugaladvance distributor at the breakerpoint assembly primary terminal.

2. Loosen the nut holding thespring in position. Move the springtoward the breaker arm pivot to de-crease tension and in the opposite di-rection to increase tension.

3. Tighten the lock nut, and thencheck spring tension. Repeat the ad-


6. Disconnect the distributor vac-uum line (if so equipped).

7. If necessary, clean and markthe timing marks.

8. Operate the engine at the spec-ified idle rpm and point the timinglight at the timing pointer.

9. If the timing is incorrect, loosenthe distributor hold down bolt androtate the distributor until the desiredinitial advance is obtained.

10. Tighten the distributor holddown bolt and check the timing again.

11. Turn off the engine.12. Remove the timing light and

connect the vacuum line.

FIG. 24-Typical V-8 EngineTiming Marks

SPARK PLUG WIREREPLACEMENT

When removing the wires from thespark plugs, grasp, twist and pull themoulded cap only. Do not pull on thewire because the wire connection in-side the cap may become separatedor the weather seal may be damaged.

170 AND 200 C.I.D. SIXCYLINDER ENGINES

The ignition wire installation isshown in Fig. 26.

Removal1. Disconnect

spark plugs and at2. Remove the

lead.

Cleaning and IRefer to section

the cleaning anddures.

Installation1. Connect the wires to the proper

spark plugs.2. Insert the ends of the wires in

the correct sockets in the distributorcap. Be sure the wires are forced allthe way down into their sockets andthat they are held firmly in position.The No.1 socket is identified on thecap. Install the wires in a clockwisedirection in the firing order (1-5-3-6-2-4) starting at the No.1 socket.

3. Install the coil high tension lead.Push all weatherseals into position.

ALL V-8 ENGINESA typical ignition wiring installa-

tion is shown in Fig. 27.

81474-8

FIG. 2S-Typical Six CylinderEngine Timing Marks

with a Rotunda 13-07 power timinglight, proceed as follows:

1. Remove the plug wire from thenumber 1 spark plug.

2. Install the spark plug adaptoron the spark plug.

3. Connect the plug wire to thespark plug adaptor.

4. Clamp the timing light sparkplug lead to the spark plug adaptor.

5. Connect the timing light batteryleads to the battery terminals.

Removal1. Disconnect the wires from the

spark plugs and distributor cap.2. Pull the wires from the brackets

- -,-LESS TENSION B2013-A

FIG. 23-Adjusting BreakerPoint Spring Tension

justment until the specified springtension is obtained.

4. Install the primary or distribu-tor-transistor lead wire, the condenserlead (if so equipped) and the jumperstrap on the centrifugal advance dis-tributor with the lockwasher andtighten the nut securely.

On the centrifugal advance dis-tributor with dual breaker points,loosen the lock nut holding the jump-er strap to the other breaker pointassembly and follow steps 2 and 3.After the adjustment has been com-pleted, connect the jumper strap.

IGNITION TIMING

TIMING MARK LOCATIONSThere are two methods of showing

the timing position. Both methodsuse the crankshaft damper and a tim-ing pointer.

One method uses degree marks onthe crankshaft pulley (Fig. 24). Thesedegree marks range from 0° or topdead center (TDC) to some valuebefore top dead center (BTDC).When checking the timing, the cor-rect degree mark should be in linewith the timing pointer when thetiming light flashes.

The other method uses degreemarks on the timing pointer (Fig.25). These also range from 0° or topdead center (TDC) to some value be-fore top dead center (BTDC). Whenchecking the timing, the correct de-gree mark should be in line with thetiming mark on the crankshaft pulleywhen the timing light flashes.

ADJUSTMENTThe procedure for checking and

adjusting the ignition timing with ascope is given in Section 1 of thispart.

To check and adjust the timing

the wires at thethe distributor cap.coil high tension

nspection3 of this part forinspection proce-


FIG. 26-6-Cylinder Engine Ignition Wiring

on the valve rocker arm covers and the cleaning and inspection proce-remove the wires. dures.

3. Remove the coil high tension ADJUSTMENTlead.

Set the spark plug gap to specifica-Cleaning and Inspection tions by bending the ground elec-Refer to section 3 of this part for trode (Fig. 28).

the cleaning and inspection proce- INSTALLATIONdures.

1. Install the spark plugs andInstallation torque each plug to 15-20 ft-lbs.1. Insert each wire in the proper When a new spark plug is installed

socket of the distributor cap. Be sure in a new replacement cylinder head,the wires are forced all the way down torque the plug to 20-30 ft-lbs.into their sockets. The No.1 socket 2. Connect the spark plug wires.is identified on the cap. Install thewires in a counterclockwise directionin the firing order (1-5-4-2-6-3-7-8)starting at the No.1 socket. Cylindersare numbered from front to rear;right bank 1-2-3-4, left bank 5-6-7-8.

FIG. 28-Checking Spark PlugGapRESISTANCE WIREREPLACEMENT

1. Cut the brown wire and the redwire (with a green stripe) from theupper quick disconnect at the dashpanel. Cut the wires as close to thequick disconnect as possible.

2. Solder a male bullet-type ter-minal to the brown wire and to thered wire (with a green stripe). Makea single terminal of the two wires.Using a female bullet terminal con-nector, connect the wires to one endof the service replacement resistancewire. Do not splice the resistancewire.

3. Drill a 3/4 -inch hole through

2. Remove the brackets from theold spark plug wire set and installthem on the new set in the same rela-tive position. Install the wires in thebrackets on the valve rocker arm cov-ers. (Fig. 27). Connect the wires tothe proper spark plugs. Install thecoil high tension lead. Be sure theNo.7 spark plug wire is positioned inthe bracket as shown in Fig. 27.

SPARK PLUGS

REMOVAL1. Remove the wire from each

spark plug by grasping, twisting andpulling the moulded cap of the wireonly. Do not pull on the wire be-cause the wire connection inside the{:.ap may become separated or theweather seal may be damaged.

2. Clean the area around eachspark plug port with compressed air,and then remove the spark plugs.

CLEANING AND INSPECI10NRefer to section 3 of this part for FIG. 27-Typicol V-8 Engine Ignition Wiring


5. Thread one end of the servicereplacement resistance wire throughthe grommet in the dash panel andconnect it to the quick disconnect

near the ignition switch. Make sure

the wire is routed through the retain-

ing clips.

one of the accessory dimples in thedash panel.

4. Install a grommet into the holedrilled in the dash panel.

CLEANING AND INSPECTION

transfer is considered excessiv~ whenit equals or exceeds the gap setting.

SECONDARY WIRINGWipe the wire with a damp cloth

and check for fraying, breaks orcracked insulation. Inspect the ter-minals and weather seals for loose-ness or corrosion. Replace any wiresthat are not in good condition.

COILWipe the coil with a damp cloth

and check for any cracks or other de-fects.

DISTRIBUTOR CAPClean the distributor cap with a

soft bristle brush and mild cleaningsolvent or mineral spirits. Dry thecap with compressed air. Inspect thecap for cracks, burned contacts, per-manent carbon tracks or dirt or cor-rosion in the sockets. Replace the capif it is defective.

SPARK PLUGSExamine the firing ends of the

spark plugs, noting the type of de-posits and the degree of electrodeerosion. Refer to Fig. 30 for the var-ious types of spark plug fouling andtheir causes.

Clean the plugs on a sand blastcleaner, following the manufacturer'sinstructions. Do Dot prolong the useof the abrasive blast as it will erodethe insulator and electrodes.

Clean the electrode surfaces witha small file (Fig. 31). Dress the elec-trodes to obtain flat parallel surfaceson both the center and side elec-trodes.

After cleaning, examine the plugcarefully for cracked or broken in-sulators, badly pitted electrodes, andother signs of failure. Replace as re-quired.

breaker plate assembly if it is defec-tive.

The breaker point assembly(ies)and condenser (if so equipped)should be replaced whenever the dis-tributor is overhauled.

Inspect all electrical wiring forfraying, breaks, etc., and replace anythat are not in good condition.

Check the distributor base forcracks or other damage.

On a loadomatic or dual advancedistributor, check the diaphragmhousing, bracket, and rod for dam-age. Check the vacuum line fitting forstripped threads or other damage.Test the vacuum fittings, case, anddiaphragm for leakage as explainedunder Distributor Tests. Replace alldefective parts.

The breaker point assembly con-sists of the stationary point bracketassembly, breaker arm and the pri-mary wire terminal.

Breaker points should be inspected,cleaned and adjusted as necessary.Breaker points can be cleaned withchloroform and a stiff bristle brush.Replace the breaker point assemblyif the contacts are badly burned orexcessive metal transfer between thepoints is evident (Fig. 29). Metal

ROTORClean the rotor with a soft bristle

brush and mild cleaning solvent ormineral spirits. Dry the rotor withcompressed air. Inspect the rotor forcracks or burning. Replace the rotorif it is defective.

CONDITION CAUSED BY

Any discoloration other than a frosted slategrey shall be considered as burned points.

BURNED

DISTRIBUTORS

Soak all parts of the distributor as-sembly (except the condenser, break-er point assembly, lubricating wick,vacuum diaphragm, distributor baseoil seal and electrical wiring) in amild cleaning solvent or mineralspirits. Do not use a harsh cleaningsolution. Wipe all parts that can notbe immersed in a solvent with a cleandry cloth.

After foreign deposits have beenloosened by soaking, scrub the partswith a soft bristle brush. Do not usea wire brush, file, or other abrasiveobject. Dry the parts with compressedair.

Examine the bushing surface(s) ofthe distributor shaft and the bush-ing(s) for wear.

Inspect the distributor cam lobesfor scoring and signs of wear. If anylobe is scored or worn, replace thecam assembly (dual advance andcentrifugal advance distributor) orthe shaft (loadomatic distributor).

Inspect the breaker plate assemblyfor signs of distortion. In addition, onthe dual advance distributor, inspectthe stationary sub-plate for worn ny-lon contact buttons. Replace the

Incorrect alignment.Incorrect voltage regulator setting.Radio condenser installed to the distributor

side of the coil.Ignition condenser of improper capacity.Extended operation of the engine at speeds

other than normal.81443-8

EXCESSIVE METALTRANSFER OR PinING

FIG. 29-Breaker Point Inspection

PART 9-1 9-19GENERAL IGNITION SYSTEM SERVICE

FIG. 31-Cleaning Spark PlugElectrode

B2581-A

FIG. 30-Spark Plug Inspection

9-20

LOADOMA TIC DISTRIBUTORS

Section Page1 Description and Operation 9-202 In-Car Adjustments and Repairs 9-20

Breaker Point and Condenser Replacement. . .9-20Vacuum Diaphragm Replacement .9-20

3 Removal and Installation. . . . . . . . . . . . . . . . . .9-21

Page. . . . . . . . . . . . . .9-21. . . . . . . . . .. .. .9-21. . . . . . . . . . . . . .9-21. . . . . . . . . . .. . .9-21. . . . . . . . . . . . . .9-21

SectionRemoval Installation 4 Major Repair Operations

Bench Disassembly.. . . .Bench Assembly. . . . . . .

FIG. 2-Spark AdvanceMechanism

vacuum falls and the valve closes.This prevents loss of venturi vacuumdue to bleed back caused by thelower manifold vacuum. This assuresfull spark advance at high enginespeed.

The spark valve functions in a sim-ilar manner to provide an intermedi-ate spark retard whenever the loadon the engine is increased to a degreewhere normal road load spark ad-vance would be too great and thewide-open throttle spark retard wouldreduce the efficiency of the engine.

FIG. 1-Breaker Plate Installed

nation of atmospheric pressure out-side the spark valve diaphragm andmanifold vacuum from within holdsthe spark valve open. When acceler-ating, manifold vacuum momentarilydrops below a predetermined pointand the calibrated spring closes thespark valve shutting off the manifoldvacuum port. Vacuum from the ven-turi prevents full spark retard.

As engine speed approaches thethrottle setting, manifold vacuum in-creases sufficiently to open the sparkvalve and allow a higher vacuum tooperate the distributor.

At high engine speed, manifold

The replacement procedures arecovered in Part 9-1, Section 2.

VACUUM DIAPHRAGMREPLACEMENT

REMOVAL1. Remove the distributor cap and

rotor.

2. Remove the vacuum line fromthe diaphragm.

3. Remove the spring clip that se-cures the diaphragm link to thebreaker plate.

4. Remove the diaphragm retain-

The direction of distributor rota-tion is clockwise as viewed from thetop of the distributor.

Engine speed and load require-ments are satisfied by the action ofthe breaker plate which is controlledby a vacuum-actuated diaphragmworking against the tension of twocalibrated breaker plate springs (Figs.1 and 2). The breaker plate is free torotate on the shaft bushing. The dia-phragm moves the breaker plate ina counterclockwise direction to ad-vance the spark, and the springsmove the plate in a clockwise direc-tion to retard the spark. The degreeof spark advance is determined by thestrength of the vacuum acting on thediaphragm.

Vacuum is transmitted to the dis-tributor diaphragm from two inter-connected passages in the carburetor.The opening of one passage is in thethroat of the venturi and the open-ing(s) of the mher passage is in thethrottle bore just above the closedthrottle plate.

All manifold vacuum to the distri-butor passes through a spark controlvalve located in the carburetor throt-tle body or main body. Under steadypart throttle operation, the sparkvalve is held open against the pres-sure of a calibrated spring. A combi-

BREAKER POINT ANDCONDENSER REPLACEMENT

ing screws and remove the diaphragm plate and attach the rod with the

spring clip.

2. Install the vacuum line in the

diaphragm assembly and tighten the

fitting.

INSTALLATION1. Install the vacuum unit on the

distributor body. Insert the tip of thevaCUllm rod through the breaker

3. Install the rotor and distributorcap.ADJUSTMENTS

Refer to Part 9-1 for the properprocedures for adjusting the breakerpoints and spark advance.

REMOVAL AND INSTAllATION

Do not rotate the crankshaft whilethe distributor is removed, or it willbe necessary to time the engine.

compression stroke. Position the dis-tributor in the block with the rotor atthe No.1 firing position. Make surethe oil pump intermediate drive shaftis properly seated in the oil pump.Install, but do not tighten, the dis-tributor retaining bolt. Rotate thedistributor body clockwise until thebreaker points are just starting toopen. Tighten the retaining bolt.

3. Connect the distributor primarywire and install the distributor cap.

4. Start the engine and adjust theignition timing to specifications witha timing light. Connect the distribu-tor vacuum line, and check the ad-vance with the timing light when theengine is accelerated.

INSTALLATION1. If the crankshaft has not been

rotated while the distributor was re-moved, position the distributor in theblock with the rotor aligned with themark previously scribed on the dis-tributor body.

Install the distributor retainingscrew.

2. If the crankshaft has been ro-tated while the distributor was re-moved, rotate the crankshaft untilthe No.1 piston is on TDC after the

REMOV AL1. Disconnect the primary wire at

the coil and remove the distributorcap.

2. Disconnect the vacuum line atthe distributor.

3. Scribe a mark on the distributorbody, indicating the position of therotor, and scribe another mark on thebody and engine block, indicating theposition of the body in the block.These lines will be used as guideswhen installing the distributor in thecorrectly timed engine.

4. Remove the retaining bolt andlock washer and lift the distributorout of the block.

MAJOR REPAIR OPERATIONSTo perform the operations in this vise. Remove the distributor cap

section, it will be necessary to remove clamps.the distributor from the car. 9. Drive out the drive gear pin

with a punch (Fig 4).BENCH DISASSEMBLY 10. If the gear and shaft are to be

The distributor assembly is shown used again, mark the gear and shaftin Fig. 3. so that the pin holes can be easily

1. Install the distributor in a vise. aligned for assembly.2. Remove the rotor and retaining 11. Press the gear off the shaft

clip. (Fig. 5). Slide the distributor shaft3. Remove the vacuum diaphragm out of the body.

rod and spring clip. Push the dia- 12. Position the distributor in aphragm rod out of the plate. Remove vise.the vacuum diaphragm unit from the 13. Remove the lock ring attach-distributor. ing the breaker plate to the upper

4. Disconnect the primary and bushing. Lift the breaker plate fromcondenser wires from the breaker the body.point terminal. Working from the in- 14. Remove the ground wire.side of the distributor, pull the pri- 15. Remove the oil filler cap andmary wire through the opening in the the oil wick.distributor. 16. Compress and insert the slotted

5. Remove the condenser. end of the bushing removal tool in6. Remove the breaker point as- the distributor body. Allow it to ex-

sembly. pand and butt against the bushing.7. Release the tension on the re- Drive out the bushing (Fig. 6).

turn springs and disconnect thesprings. Do not stretch the springs as BENCH ASSEMBLYdistortion may result, making it im- 1. Oil the bushing and position it inpossible to obtain an adjustment. If the body with the lock ring end up.the springs are distorted, discard Install the bushing (Fig. 7). Press thethem. tool until the bushing bottoms firm-

8. Remove the distributor from the Iy a~ainst the distributor body.

2. Burnish the bushing to theproper size (Fig. 8).

3. Install the ground wire. Positionthe breaker plate in the body. Installthe lock ring to secure the plate.

4. Position a new breaker pointassembly on the breaker plate. Besure the pivot pin enters the hole inthe breaker plate.

S. Connect the ground wire underthe breaker point screw at the endclosest to the adjustment slot. Installthe other screw and lock washer atthe opposite end of the assembly.

6. Install a new condenser. Passthe primary wire assembly throughthe opening in the distributor, work-ing from the inside to the outside ofthe distributor housing. Pull the wirethrough the opening until the locatingstop is flush with the inside of the dis-tributor. Place the condenser lead,primary lead, lock washer, and nuton the primary terminal.

7. Install the return springs on theadjustment and breaker plate posts.

Make certain that the primaryspring is installed closest to the con-denser.

8. Install the vacuum diaphragmon the distributor body.

9. Insert the tip of the vacuum dia-

~ RETAINING CLIP12213

~,

FIG. 6-Bushing Removal

82135-8

FIG. 3-Distributor Assembly FIG. 7 -Bushing Installation

FIG. 5-Gear Removal

block on the breaker points. Theshaft and gear are replaced as an as-sembly. One part should not be re-placed without replacing the other.

11. Place the distributor locatingand installing fixture on the distribu-tor. Place a 0.022 feeler gauge be-tween the backing screw and theshaft. Tighten the backing screw

FIG. 8-Burnishing Bushing

enough to remove all shaft end playand remove the feeler gauge.

12. Place the spacer on the gearend of the shaft. Press the gear onthe shaft (Fig. 9). If a new shaft isbeing installed, drill the shaft with a

"'"'~"' 61025-6

FIG. 4-Gear Pin Removal orInstallation

phragm rod through the breakerplate. Attach the rod with the springclip.

10. Slide the shaft into the bodyusing care not to damage the rubbing

PART 9-2 LOADOMA'[!C DISTRIBUTORS 9-23

Ys -inch drill using the pin hole in the

gear shoulder as a guide.

13. Install the pin through the

gear and shaft. Install the distributor

cap clamps. Lubricate the cam with

distributor cam lubricant.

14. Fill the oil reservoir with ap-

proximately 40 drops of engine oil.

Install the oil wick and the filler cap.

15. Refer to Part 9-1 and adjust

the breaker point spring tension, alignthe breaker points, and adjust the

gap. Check the vacuum advance, and

the breaker point dwell and resist-

ance.

9-24

DUAL ADVANCEDISTRIBUTORS

Page.9-24.9-25.9-25.9-25.9-25

Page9-279-279-279-279-279-2R

Section3 Removal and Installation

Removal Installation. . . . . . . . . . . .

4 Major Repair OperationsBench Disassembly. . . . .Bench Assembly. . . . . . .

SectionI Description and Operation. . . . . . . . . . . . .2 In-Car Adjustments and Repairs. . . . . . . .

Breaker Point and Condenser ReplacementVacuum Diaphragm Replacement. Breaker Plate and Sub-Plate Replacement.

Cam and Centrifugal Advance MechanismReplacement , 9-25

DESCRIPTION AND OPERATION

LUBRICATING WICK

The dual advance distributor hastwo independently operated sparkadvance systems. A centrifugal ad-vance mechanism (Fig. 1) is locatedbelow the stationary sub-plate assem-bly, and a vacuum operated sparkcontrol diaphragm is located on theside of the distributor base (Fig. 2).As speed increases, the centrifugalweights cause the cam to advance ormove ahead with respect to the dis-tributor drive shaft. The rate of ad-vance is controlled by calibratedsprings.

The vacuum advance mechanismhas a spring-loaded diaphragmwhich is connected to the breakerplate. The spring-loaded side of thediaphragm is airtight and is con-nected through a vacuum line to thecarburetor throttle bore. When thethrottle plates open, the distributorvacuum passage is exposed to mani-fold vacuum, which causes the dia-phragm to move against the tensionof the spring. This action causes themovable breaker plate to pivot onthe stationary sub-plate. The break-er point rubbing block, which ispositioned on the opposite side ofthe cam from the pivot pin, thenmoves against distributor rotationand advances the spark timing. Asthe movable breaker plate is rotatedfrom retard position to full advanceposition, the dwell decreases slightly.This is because the breaker pointrubbing block and the cam rotate ondifferent axes.

FIG. 1

DISTIRBUTOR SHAFT/" --

-Typical Centrifugal Advance Mechanism

9-25PART 9-3 - DUAL ADVANCE DISTRIBUTORS

FIG. 2-Vacuum Advance Mechanism

IN-CAR ADJUSTMENTS AND REPAIRS

4. Install the rotor and the dis-tributor cap.


The replacement procedures arecovered in Part 9-1, Section 2. BREAKER PLATE AND

SUB-PLATE REPLACEMENTRefer to Figs. 3 and 4 for the prop-

er location of parts.

secures the breaker plate to the sub-plate.

3. Install the sub-plate hold downscrews (the ground wire should beunder the sub-plate hold down screwnear the primary wire opening in thedistributor).

4. Working from the inside of thedistributor, push the primary wirethrough the opening in the distribu-tor.

S. Install the breaker point assem-bly, the condenser and the vacuumdiaphragm.



the rotor.2. Remove the breaker point as-

sembly, the condenser, and the vacu-um diaphragm.

3. Working from the inside of thedistributor, pull the primary wirethrough the opening in the distribu-tor.

4. Remove the spring clip, the flatwasher, and the spring washer secur-ing the breaker plate to the sub-plate.

5. Remove the sub-plate retainingscrews and lift both plates out of thedistributor.

INSTALLATION1. Place the breaker plate in posi-

tion on the sub-plate.2. Install the spring washer, the

flat washer, and the spring clip that

VACUUM DIAPHRAGMREPLACEMENT


the rotor.1. Remove the vacuum line from

the diaphragm fitting.3. Remove the spring clip that se-

cures the diaphragm link to the mov-able breaker plate.

4. Remove the diaphragm retain-ing screws and slide the diaphragmout of the distributor.

INSTALLATION1. Slide the diaphragm into the

opening in the distributor and placethe link in its position.

1. Install the spring clip that se-cures the diaphragm link to themovable breaker plate and the dia-phragm retaining screws.

3. Install the vacuum line on thediaphragm fitting.

CAM AND CENTRIFUGALADVANCE MECHANISMREPLACEMENT


the rotor.2. Working from the inside of the

distributor, pull the primary wirethrough the opening in the distribu-tor.

3. Remove the sub-plate retaining


5. Carefully unhook and removethe weight springs.

6. Lift the lubricating wick fromthe cam assembly. Remove the camassembly retainer and lift the cam as-sembly off the distributor shaft. Re-move the thrust washer.

7. Remove the weight retainersand lift the weights out of the dis-tributor.

BREAKER POINT ASSEMBLY B2274.B

FIG. 3-Breaker Plate Installed-Pivot-Type Pointsscrews and lift the plate assembly weight springs and its brackets. Alsoout of the distributor. mark one of the weights and its pivot

4. Mark one of the distributor pin.VACUUM DIAPHRAGM GROUND WIRE

INSTALLATION

1. Fill the grooves in the weightpivot pins ~ith distributor cam lubri-cant (C4AZ-19D530-A).

2. Position the weights in the dis-tributor (the marked weight is placedon the marked pivot pin) and installthe weight retainers.

3. Place the thrust washer on theshaft.

4. Fill the grooves in the upperportion of the distributor shaft withdistributor cam lubricant (C4AZ-19D530-A).

5. Install the cam assembly. Besure that the marked spring bracketon the cam assembly is near themarked spring bracket on the stopplate.

If a new cam is being installed,make sure that the cam is installedwith the hypalon covered stop in thecorrect cam plate control slot. Thiscan be done by measuring the lengthof the slot used on the old cam andby using the corresponding slot on thenew cam. Some of the cams will havethe size of the slot in degreesstamped near the slot. If the wrongslot is used, an incorrect maximumadvance will be obtained.

Place a light film of distributorcam lubricant on the distributor camlobes. Install the retainer and thewick. Saturate the wick with SAElOW engine oil.

6. Install the weight springs. Besure that the marked spring is at-tached to the marked spring brack-ets.

7. Install the sub-plate assembly.8. Working from the inside of the

distributor, push the primary wirethrough the opening in the distribu-tor.


.BREAKER POINT ASSEMBLY

FIG. 4-Breaker Plate Installed-Pivotless Points62275.6

ADJUSTMENTS

Refer to Part 9-1, Section 2 forthe adjustment procedures.

PART 9-3 - DUAL ADVANCE DISTRIBUTORS 9-27

REMOVAL AND INSTALLATION

INSTALLATION1. If the crankshaft was rotated

while the distributor was removedfrom the engine, it will be necessaryto time the engine. Rotate the crank-shaft until No.1 piston is on TDCafter the compression stroke. Alignthe TDC mark on the timing pointerwith the timing pin on the crankshaftdamper. Position the distributor inthe block with the rotor at the No.1firing position.

Make sure the oil pump interme-diate shaft properly engages the dis-tributor shaft. It may be necessary tocrank the engine with the starter,after the distributor drive gear ispartially engaged, in order to engagethe oil pump intermediate shaft.

Install, but do not tighten, the re-

taining clamp and bolt. Rotate thedistributor body counterclockwiseuntil the breaker points are just start-ing to open. Tighten the clamp.

2. If the crankshaft has not beenrotated, position the distributor in theblock with the rotor aligned with themark previously scribed on the dis-tributor body, and the marks on thedistributor body and engine block inalignment. Install the retainingclamp.

3. Install the distributor cap.4. Connect the primary wire to the

coil.5. Check the ignition timing with

a timing light and adjust to specifi-cations if necessary. Connect the vac-uum line, and check the advance withthe timing light when the engine isaccelerated.

REMOVAL1. Disconnect the primary wire at

the coil. Disconnect the vacuum ad-vance line at the distributor. Removethe distributor cap.

2. Scribe a mark on the distribu-tor body and engine block indicatingthe position of the body in the block,and scribe another mark on the dis-tributor body indicating the positionof the rotor. These marks can be usedas guides when installing the distrib-utor in a correctly timed engine.

3. Remove the distributor holddown bolt and clamp. Lift the dis-tributor out of the block.

Do not rotate the crankshaft whilethe distributor is removed, or it willbe necessary to time the engine.

MAJOR REPAIR OPERATIONS

cures the diaphragm link to themoveable breaker plate.

5. Remove the diaphragm retain-ing screws and slide the diaphragmout of the distributor.


To perform the operations in thissection, it will be necessary to removethe distributor from the engine andplace it in a vise.

BENCH DISASSEMBLYThe distributor assembly is shown

in Fig. 5.1. Remove the rotor.

2. Disconnect the primary and thecondenser wires from the breakerpoint assembly.

3. Remove the breaker point as-sembly and condenser retainingscrews. Lift the breaker point assem-bly and condenser out of the distrib-utor.

4. Remove the spring clip that se-

PIN-1214S-r LOWER BUSHING CO}~ _DRIVE GEAR-1239012132 -,- '-.

'-.. '~PIN-67S55

/OiLSEAL-12143

DIAPHRAGM ASSEMBL Y-12370

-_.~I'

CLAMp-12144 ~HOUSING-12130.

SPRING::'12191 or 12192

WEIGHT-J,2188

WEIGHT R~TAINER-379023

1CAM ASSEMBL Y-

RETAINER-12177, ... C'3;

STATIONARY SUB.PLATE-12151MOVEABLE BREAKER PLATE-12151 !,~ ""' \l---5PRING-12191 0,'12192

BREAKER POI~+ ASSEMB~Y:i2171 " . ~ ~"'-WEIGHT-nI88

THRUST WASHER-CONDENSER-12300 "" ! 12179~ \. V LUBRICATING WICK-12133

.. ~~ ' ~~ --- SPRING WASHER-372395 .,

'II'. ~ \. ,, FLAT WAS HER-372396

;; RET AINER-351825

~--12264

CTnr

-~

PIN::12145 ~.,RETURN SPP""'"

""UPPERBUSHING -"

12f20 .CLAMP-

'SHA~r -12)75 .,;' 12144

~

CALIBRATINI: WAo;I-IF~o;

GASKETJ I

of'0

:-{"TVACUUM CONNECTION

PRIMARY WIRE- 12216t82265.8

FIG. 5-Distributor Assembly

Tool-12132-H

FIG. 8-Collar Pin Removal orInstallation

7. Remove the spring clip, the flatwasher, and the spring washer secur-ing the breaker plate to the sub-plate.

8. Remove the sub-plate retainingscrews and lift both plates out of thedistributor.

9. Mark one of the distributorweight springs and its brackets. Alsomark one of the weights and its pivotpin.


11. Lift the lubricating wick fromthe cam assembly. Remove the camassembly retainer and lift the cam as-sembly off the distributor shaft. Re-move the thrust washer.

12. Remove the weight retainersand lift the weights out of the distrib-utor.

13. Remove the distributor capclamps.

14. If the gear and shaft are tobe used again, mark the gear andthe shaft so that the pin holes can beeasily aligned for assembly. Removethe gear roll pin (Fig. 6), and thenremove the gear (Fig. 7).

FIG. la-Lower BushingRemoval

Tool-T52l-12131-'-"

B1036-C

FIG. 6-Gear Pin Removal orInstallation

FIG. 11Removal

-Upper Bushing

FIG. 9-Shaft Removal17. Refer to Figs. 10 and 11 and

remove the distributor shaft upperand lower bushings.

BENCH ASSEMBLYORIGINAL SHAFf AND GEAR

1. Oil the new upper bushing, andposition it on the bushing replacertool. Install the bushing (Fig. 12).When the tool bottoms against thedistributor base, the bushing will beinstalled to the correct depth.

2. Burn the bushing to the propersize (Fig. 13).

3. Invert the distributor and installand burnish the lower bushing in asimilar manner.

4. Oil the shaft and slide it intothe distributor body.

5. Place the collar in position onthe shaft and align the holes in thecollar and the shaft, then install anew pin. Install the distributor capclamps.

6. Check the shaft end play witha feeler gauge placed between thecollar and the base of the distributor.If the end play is not within specifi-cations, replace the shaft and gear.

7. Attach the distributor shaftsupporting tool to the distributor.Tighten the backing screw in the toolenough to remove all shaft end play.

8. Install the assembly in a Dress.

FIG. 7-Gear Removal

15. Remove the shaft collar rollpin (Fig. 8).

16. Invert the distributor and placeit on a support plate in a positionthat will allow the distributor shaftto clear the support plate and pressthe shaft out of the collar and thedistributor housing (Fig. 9).

Press the gear on the shaft (Fig. 14),using the marks made on the gearand shaft as guides to align the pinholes.

9. Remove the distributor from thepress. Install the gear retaining pin(Fig. 6).

10. Position the distributor in avise. Fill the grooves in the weightpivot pins with a distributor cam lu-bricant.

11. Position the weights in the dis-

9-29PART 9-3 DUAL ADY ANCE DISTRIBUTORS

FIG. 12-Upper BushingInstallation

NEW SHAFT AND GEAR

The shaft and gear are replacedas an assembly. One part should notbe replaced without replacing theother. Refer to Fig. 5 for the correctlocation of the parts.

1. Follow steps 1, 2, 3, and 4 un-der "Installing Original Shaft I.ndGear-Conventional Ignition SystemDistributor. .,

2. Attach the distributor shaft sup-porting tool to the distributor andinstall the assembly in a vise. Inserta O.O24-inch feeler gauge betweenthe backing screw and the shaft.Tighten the backing screw on thetool enough to remove all shaft endplay. Remove the feeler gauge andallow the shaft to rest on the back-ing screw. Slide the collar on theshaft. While holding the collar inplace against the distributor base(Fig. 15), drill a 118 -inch hole'throughthe shaft using the access openingin the collar as a pilot,

3. Position the gear on the end ofthe shaft. Install the assembly in apress.

FIG. 13-Burnishing Bushing

portion of the distributor shaft withdistributor cam lubricant (C4AZ-19D530-A).


If a new cam is being installed,make sure that the cam is installedwith the hypalon covered stop in thecorrect cam plate control slot. Thiscan be done by measuring the lengthof the slot used on the old cam andby using the corresponding slot on thenew cam. Some of the cams will havethe size of the slot in degrees stampednear the slot. If the wrong slot isused, an incorrect maximum advancewill be obtained.


15. Install the weight springs. Besure that the marked spring is at-tached to the marked spring brackets.

16. Place the breaker plate in po-sition on the sub-plate.

17. Install the spring washer, theflat washer, and the spring clip thatsecures the breaker plate to the sub-plate.

18. Install the sub-plate hold downscrews (the ground wire should beunder the sub-plate hold down screwnear the primary wire opening in thedistributor).

19. Working from the inside of thedistributor, push the primary wirethrough the opening in distributor.

20. Slide the diaphragm into theopening in the distributor and placethe link in its position.

21. Install the spring clip that se-cures the diaphragm link to themoveable breaker plate.

22. Place the breaker point as-sembly and the condenser in positionand install the retaining screws. Besure to place the ground wire underthe breaker point assembly screw far-thest from the breaker point contacts.Align and adjust the breaker point as-sembly by following the procedurein Part 9-1.

23. Connect the primary and con-denser leads to the breaker point as-sembly.


25. Check and adjust (if neces-sary) the centrifugal and vacuumadvance (Refer to Part 9-1, Section1).

B1387-D

FIG. 1 5-New Shaft and GearInstallation

4. With the backing screw on thesupport tool tightened enough to re-move all end play, press the gear onthe shaft to the specified distancefrom the bottom face of the gear tothe bottom face of the distributormounting flange (Fig. 15). Drill aVB-inch hole through the shaft usingthe hole in the gear as a pilot.

S. Remove the distributor fromthe press and remove the supporttool. Install the collar retaining pin(Fig. 8) and the gear retaining pin(Fig. 6).

6. Complete the assembly by fol-lowing steps 9 thru 25 under Install-ing Original Shaft and Gear.

tributor (the marked weight is placedon the marked pivot pin) and installthe weight retainers.

U. Place the thrust washer on theshaft.

.13. Fill the grooves in the upper

9-30

CENTRIFUGAL ADVANCEDISTRIBUTORS

Page. . . . . .. . . .9-30

.. . . . . . ., .9-30

Section PageMechanism Replacement.. . . . . . . . . . . . . . .9-31

3 Removal and Installation 9-31Removal 9-31Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-32

4 Major Repair Operations . . . . . .9-32BenchDisassembly 9-32BenchAssembly 9-33

Section1 Description and Operation... . . .2 In-Car Adjustments and Repairs. .

Breaker Point and Condenser

Replacement Breaker Point and Condenser Plate

Replacement ." "..'...'

Cam and Centrifugal Advance

9-30

9-30

DESCRIPTION AND OPERATION

The centrifugal advance distribu-tor is a straight mechanical-type unit.A governor-type centrifugal advanceis located below the stationarybreaker plate (Fig. 1). Two centrif-ugal weights cause the cam to ad-vance or move ahead with respectto the distributor drive shaft. Therate of advance is controlled by twocalibrated springs.

The breaker points are located onthe stationary breaker plate and areconnected in parallel with an insu-lated jumper strap. One breakerpoint assembly closes the primarycircuit and the other opens theprimary circuit. This type of con-struction results in a greater amountof dwell with approximately thesame amount of gap spacing as thesingle breaker point distributor. Thebreaker arm spring tension is greaterthan on the loadomatic or dual ad-vance distributors. This increaseddwell and breaker arm spring tensionassures reserve spark plug voltagefor high speed performance.

EJ IN-CAR ADJUSTMENTS AND REPAIRS


BREAKER POINT ANDCONDENSER PLATEREPLACEMENT

REMOVAL1. Remove the distributor cap

and the rotor.

The replacement procedures are

in Part 9-1, Section 2.

2. Remove the breaker point as-semblies and the condenser.


4. Remove the breaker point and

PART 9-4 CENTRIFUGAL ADVANCE DISTRIBUTORS 9-31

wrong slot is used, an incorrect max-imum advance will be obtained.

Place a light film of distributorcam lubricant (C4AZ-l9D530-A)on the distributor cam lobes. Installthe retainer and the wick. Saturatethe wick with SAE lOW engine oil.


condenser plate retaining screws andlift the plate out of the distributor.

INSTALLATIONThe breaker point and condenser

plate assembly installation is shownin Fig. 2.

1. Place the breaker point andcondenser plate in position and in-stall the retaining screws.

2. Working from the inside of thedistributor. push the primary wirethrough the opening in the distribu-tor housing.

3. Install the breaker point assem-blies and the condenser.


CAM AND CENTRIFUGALADVANCE MECHANISMREPLACEMENT

REMOVAL1. Remove the distributor cap

and the rotor.2. Working from the inside of

the distributor. pull the primary wirethrough the opening in the distribu-tor.

3. Remove the breaker point andcondenser plate retaining screws andlift the plate assembly out of the dis-tributor.

4. Mark one of the distributorweight springs and its brackets. Alsomark one of the weights and its pivotpin.


6. Lift the lubricating wick fromthe cam assembly. Remove the camassembly retainer and lift the camassembly off the distributor shaft.Remove the thrust washer.


FIG. 2-Breaker Plate Installed

placed on the marked pivot pin) andinstall the weight retainers.

3. Place the thrust washer on theshaft.



If a new cam assembly is beinginstalled, make sure that the cam isinstalled with the hypalon coveredstop in the correct cam plate controlslot. This can be done by measuringthe length of the slot used on the oldcam and by using the correspondingslot on the new cam. Some of thecams will have the size of the slot indegrees stamped near the slot. If the

INSTALLATION1. Fill the grooves in the weight

pivot pins with distributor cam lubri-cant (C4AZ-19D530-A).

2. Position the weights in the dis-tributor (the marked ~ght is

7. Install the breaker point andcondenser plate assembly.

8. Working from the inside of thedistributor, push the primary wirethrough the opening in the distribu-tor.


ADJUSTMENTSRefer to Part 9-1, Section 3 for

the adjustment procedures.

REMOVAL AND INSTAllATION

tor body and engine block indicatingthe position of the body in the block,and scribe another mark on the dis-tributor body indicating the positionof the rotor. These marks can be

used as guides when installing thedistributor in a correctly timed en-gine.

3. Remove the distributor holddown cap bolt and clamp, and then

REMOVAL1. Disconnect the primary wire

at the coil. Remove the distributorcap.

2. Scribe a mark on the distribu-

lift the distributor out of the block.Do not rotate the crankshaft

while the distributor is removed, orit will be necessary to time the en-gine.

INSTALLATION1. If the crankshaft was rotated

while the distributor was removedfrom the engine, it will be necessaryto time the engine. Rotate the crank-shaft until No.1 piston is on TDC(after the compression stroke).Align the TDC mark on the timingpointer with the timing pin on the

crankshaft damper. Position the dis-tributor in the block with the rotorat the No.1 firing position.

If the crankshaft has not beenrotated, position the distributor inthe block with rotor aligned withthe mark previously scribed on thedistributor body, and the marks onthe distributor body and engineblock in alignment. Install the re-taining clamp.

Make sure the oil pump inter-mediate shaft properly engages thedistributor shaft. It may be neces-sary to crank the engine with the

starter, after the distributor drivegear is partially engaged, in order toengage oil pump intermediate shaft.

2. Install, but do not tighten, theretaining clamp and bolt. Rotate thedistributor body counterclockwiseuntil one set of breaker points arejust starting to open. Tighten theclamp.

3. Install the distributor cap.4. Connect the primary wire to

the coil.5. Check the ignition timing with

a timing light and adjust it if neces-sary.

MAJOR REPAIR OPERATIONS

To perform the operations in thissection, it will be necessary to re-move the distributor from the carand place it in a vise.

the distributor, pull the primary wirethrough the opening in the distribu-tor.

5. Remove the breaker point andcondenser plate retaining screws andlift the plate out of the distributor.

6. Mark one of the distributorweight springs and its brackets. Alsomark one of the weights and its piv-ot pin.


8. Lift the lubricating wick fromthe cam assembly. Remove the camassembly retainer and lift the camassembly off the distributor shaft.Remove the thrust washer.


10. Remove the distributor capclamps.

11. If the gear and shaft are tobe used again, mark the gear andthe shaft so that the pin holes can beeasily aligned for assembly. Removethe gear roll pin (Fig. 4), and thenremove the gear (Fig. 5).

12. Remove the shaft collar rollpin (Fig. 6).

13. Invert the distributor andplace it on a support in a positionthat will allow the distributor shaftto clear the support plate and pressthe shaft out of the collar and thedistributor housing (Fig. 7).

14. Remove the distributor shaftupper bushing (Fig. 8).

15. Remove the distributor shaftlower bushing (Fig. 9).

BENCH DISASSEMBLY

Refer to Fig. 3 for the location ofparts.

1. Remove the rotor.2. Disconnect the primary wire,

the jumper strap, and the condenserwire from the breaker point assem-blies.

3. Remove the retaining screwsfrom the breaker point assembliesand condenser. Lift the breakerpoint assemblies and the condenserout of the distributor.

4. Working from the inside of

FIG. 3-Distributor Assembly

9-33PART 9-4 - CENTRIFUGAL ADVANCE DISTRIBUTORS

Ram

B2281.A

FIG. 4-Gear Pin Removalor Installation

FIG. 5-Gear Removal

FIG. 7-Shaft Removal

FIG. 10-Upper BushingInstallationFIG. 8-Upper Bushing Removal

tor. If the end play is not withinlimits, replace the shaft and gear.

7. Attach the distributor shaftsupporting tool to the distributor.Tighten the backing screw in thetool enough to remove all shaft endplay.

8. Install the assembly in a press.Press the gear on the shaft (Fig.12), using the marks made on thegear and shaft as guides to align thepin holes.

.Too/-T52L.12131.CAD

B2017-C

FIG. 6-Collar Pin Removal orInstallation

BENCH ASSEMBLYORIGINAL SHAFf AND GEAR

1. Oil the new upper bushing, andinstall it on the bushing replacertool. Then install the upper bushing(Fig. 10). When the tool bottomsagainst the distributor base, thebushing will be installed to the cor-rect depth.

2. Burnish the bushing to theproper size (Fig. 11).

3. Invert the distributor and in-stall the lower bushing in a similarmanner.

4. Oil the shaft and slide it intothe distributor body.

5. Place the collar in position onthe shaft and align the holes in thecollar and shaft, then install a newpin (Fig. 6). Install the distributorcap clamps.

6. Check the shaft end play witha feeler gauge placed between thecollar and the base of the distribu-


Tool-T57L-12390-A,

Detail 3 ~

~TIGHTEN SCREW

ENOUGH TOREMOVE ALLSHAFT END

PLAY

Tool-T57L-J2390-A,

Deloil J

~

...

FIG. 12-0riginal Shaft andGear Installation

Tighten the backing screw on thetool enough to remove all shaft endplay, then remove the feeler gaugeand allow the shaft to rest on thebacking screw. Slide the collar onthe shaft. While holding the collar inplace against the distributor base,drill a 1/8 -inch hole through the shaftusing the hole in the collar as a pilot.

3. Position the gear on the endof the shaft. Install the assembly ina press.

4. With the backing screw on thesupport tool tightened enough to re-move all end play, press the gear onthe shaft to the specified distancefrom the bottom face of the gear tothe bottom face of the distributormounting flange (Fig. 13). Drill al/s-inch hole through the shaft usingthe hole in the gear as a pilot.

S. Remove the distributor fromthe press and remove the supporttool. Install the collar retaining pin(Fig. 6) and the gear retaining pin(Fig. 4).

6. Complete the assembly by fol-lowing steps 10 thru 22 under In-stalling Original Shaft and Gear.

9. Remove the distributor fromthe press. Install the gear retainingpin (Fig. 4).

10. Position the distributor in avise. Fill the grooves in the weightpivot pins with distributor cam lubri-cant (C4AZ-19D530-A).

11. Position the weights in thedistributor (the marked weight isplaced on the marked pivot pin) andinstall the weight retainers.

12. Place the thrust washer onthe shaft.



If a new cam assembly is beinginstalled, make sure that the cam isinstalled with the hypalon coveredstop in the correct cam plate controlslot. This can be done by measuringthe length of the slot used on the

old cam and by using the corre-sponding slot on the new cam. Someof the cams will have the size of theslot in degrees stamped near theslot. If the wrong slot is used, an in-correct maximum advance will beobtained.



16. Place the breaker point andcondenser plate in position and in-stall the retaining screws.

17. Working from the inside ofthe distributor, push the primarywire through the opening in the dis-tributor housing.

18. Place the breaker point as-semblies and the condenser in posi-tion and install the retaining screws.

19. Align and adjust the breakerpoint assemblies by following theprocedure in Part 9-1.

20. Connect the primary wire, thejumper strap, and the condenserwire to the breaker point assemblies.


22. Check and adjust (if neces-sary) the centrifugal advance mech-anism (Refer to Part 9-1).

NEW SHAFf AND GEARThe shaft and gear are replaced

as an assembly. One part should notbe replaced without replacing theother.

1. Follow steps 1, 2, 3, and 4 un-der Installing Original Shaft andGear.

2. Attach the distributor shaftsupporting tool to the distributor andinstall the assembly in a vise. Inserta O.O24-inch feeler gauge betweenthe backin~ screw and the shaft.

61633-C

FIG. 1 3-New Shaft and GearInstallation

9-3~

SPECIFICATIONS

DISTRIBUTOR

GENERAL

CONDENSER

APPLICATION TABLE

ThermactorEmission System DistributorTransmission

EngineStd. IA~IWiihI-wi"ij;Oji"i"ITYii81 No. (12127)

170 Six

170 Six

170 Six

170 Six ,t

200 Six Ii

200 Six

200 Six

200 Six

2892-V .

2892-V ,.

2892-V

289 2-V

2894.V

289 4-V

289 4-V

289 HP 390 2-V

3902-V

3902.V

3902-V '"

:390 4-V '-

3904-V

3904-V

CD Loadomatic

x-x

xDIMENSIONS x -

xx

x-x

xx -

x

.Q) C5DF-C

@ C6DF-A

CD C5DF-K

@ C6(>F-D

Q) C5DF-E

@ C6DF-C

CD C5DF-K

@ C6DF-E

@ C5AF.M

@ C6AF-J

@ C5AF-N

@ C6AF-S

@ C5GF-A

@ C6ZF-A

@ C6ZF.B

@ C50F-E

@ C6AF-A

@ C6AF-K

@ C6Af.B

@ C6AF-T

@ C6AF-C

@ C6AF-D

@ C6AF-L

-x

xxxIGNITION TIMING

xx

xx

x -xx

x

-xX -I

X

XX !

X '"X 'i ;;

X

X

X' ., X

,i X

X X-

XX

.X. '.""-..

X

XX

~..,.x.~ X '

X

X X

@ Dual Advance (!) Centrifugal

ADVANCE CHARACTERISTICS


C5AF-12127 -M C5DF-12127-E

C5DF-12127-K

CSAF-12127 -N

C5GF-12127-A

C5DF-12127-C

C50F-12127-E

CENTRIFUGAL ADVANCE: Set the test stand to 0° at250 rpm and 0 inches of mercury.

Distributor Advance(rpm) (Degrees)

650 2l/4-3%750 4-51/21000 61/2-71/21600 71/2-83/42000 8l/4':9%

Maximum Advance Limit

Vacuum (Inchesof Mercury)

00000

14°

9-37PART 9-5 -SPECIFICATIONS

C6AF-12127 -DC6AF-12127 -A

C6AF-12127 -8 C6AF-12127 -J


000

CENTRIFUGAL ADVANCE: Set the test stand to O' at250 rpm and 0 inches of mercury. -


600 6-71000 11-121800 13Y2-15

Maximum Advance Limit 16°

Advance(Degrees)

0-12-55-8


71316

VACUUM ADVANCE: Set the test stand to 0" at 1000rpm and 0 inches of mercury. -

Distributor(rpm)100010001000

Maimum Advance Limit go

C6AF-12127 -KC6AF-12127 -C

CENTRIFUGAL ADVANCE: Set the test stand to 0° at250 rpm and 0 inches of mercury. -


600 2'/4-3'/41200 5%-71600 7'/4-81h.2000 83/4-10'/4


CENTRIFUGAL ADVANCE: Set the test stand to O' at250 rpm and 0 inches of mercury.

Distributor Advance(rpm) (Degrees)500 2-31000 6Yz-71/41300 73/4-92000 11Y2-13


Vacuum (Inchesof Mercury

0000


0000

16°14°

VACUUM ADVANCE: Set the test stand to O' at 1000rpm and 0 inches of mercury.

Distributor Advance(rpm) (Degrees)1000 0-11000 6-91000 81/4-111/4

Maximum Advance Limit. . . . . . .


51317

VACUUM ADVANCE: Set the test stand to 0° at 1000rpm and 0 inches of mercury. ---

Distributor Advance(rpm) (Degrees)1000 0-11000 6-91000 8114-10114



51317

12°12°


C6AF-12127-L C6DF-12127 -A


0000

CENTRIFUGAL ADVANCE: Set the test stand to 0° at250 rpm and 0 inches of mercury.

Distributor Advance(rpm) (Degrees)500 0-1/2900 61/4-71/41200 91/2-101/21'800 121/2-13%

Maximum Advance Limit. . . . . . . . 16°



51015

Distributor Advance(rpm) (Degrees)1000 0-11000 31/4-61/41000 7-101/4

Maximum Advance Limit. . . . . . . . 12°

C6DF-12127 -CC6AF-12127 -S

CENTRIFUGAL ADVANCE: Set the test stand to O' at250 rpm and 0 inches' of mercury.

Distributor Advance Vacuum (Inches(rpm) (Degrees) of Mercury)

300 0-Y2 0600 2\14-3\14 0900 6\14-7\14 01200 9-10 01800 11~/4-13\14 0

Maximum Advance Limit 16'

Distributor Ad~ance(rpm) (Degrees)1000 0-11000 7-101000 9Y2-12Y2



41015

.12V2°

C6DF-12127 -DC6AF-12127-T

CENTRIFUGAL ADVANCE: Set the test stand to O' at250 rpm and 0 inches of mercury.CENTRIFUGAL ADVANCE: Set the test stand to 0° at

250 rpm and 0 inches of mercury.Distributor Advance

(rpm) (Degrees)300 0-Y2600 2Y2-3Y2900 7%-8%1200 9l/4-10Y21800 121/2-13%

Maximum Advance Limit. . . . . . . .


00000

. . . . . . . . . . . .160

Distributor Advance(rpm) (Degrees)475 lY4-2Y4700 33/4-43/41300 7-8Y41800 93/4-11



0000

16°



51015

Distributor Advance(rpm) (Degrees)1000 0-11000 6-91000 81/2-111/2



51318


Distributor Advance(rpm) (Degrees)1000 0-11000 3-61000 3-6

Maximum Advance Limit12° .6°

9-39PART 9-5 SPECIFICATIONS

SPARK PLUGSC6DF-12127 -E

COIL

.1.40-1.54(75°P.)8000-8800(75°P.). . . . . . . . . . . . .4.5. . . . . . . . . . . . .2.5

, .1.30-1.40(75°P.)

Primary Resistance (Ohms) Secondary Resistance (Ohms) ...

Amperage Draw-Engine Stopped-Engine Idling.

Primary Circuit Resistor. . . . . . . .

C6ZF-12127-ASPECIAL TOOLS

C6ZF-12127 -8

Group 9 Ignition System

Documents

Transcript of Group 9 Ignition System