POST 1, I-6 Engines, 232 & 258 from '78 to '90, 'TeamRush' Ignition Upgrade.
POST 2, V-8 Engines, AMC 304, 360, 401 From '78 to '90, 'TeamRush' Upgrade.
POST 3, 'Import' Replacement Module Failure & How You Can Fix It.
POST 4, The MOST POWERFUL Ignition You Can Easily Afford & Install.
POST 5, MAKING YOUR IGNITION MORE OFF ROAD READY AND EFFICIENT.
POST 6, IGNITION 'SECRETS', THINGS YOU WON'T FIND EASILY ANYWHERE ELSE, PART 1.
POST 10, IGNITION 'SECRETS', THINGS YOU WON'T FIND EASILY ANYWHERE ELSE, PART 2.
POST 1. I-6 Engines, 232 & 258 from '78 to '90, 'TeamRush' Ignition Upgrade
Jeep Used AMC I-6 engines, The 232 Cubic Inch, and the 258 Cubic Inch,
From '71 to '76 In CJ vehicles.
But here, we are dealing with the '78 to '86 FACTORY Ignition Systems.
The Factory System Used was the Jeep Version of the (Ford) 'Motorcraft Distributor' and 'DuraSpark' ignition module.
The distributor it's self looks like these pictures...
SHORT, SMALL DIAMETER CAP & ROTOR that lets your not so powerful SINGLE SPARK jump to electrical 'GROUND' inside the distributor cap, called 'Ground Fire' when it 'Grounds' out to the distributor shaft, distributor housing, ect...
Or lets that spark energy jump to the WRONG spark plug terminal causing 'Cross Fire' inside the distributor cap...
The ONLY way to stop a bunch of the spark jumping around where it should NOT be is to get a 'Taller' Rotor to get the spark energy up and away from the Electrical 'Ground' the shaft/housing represent,
And to get a WIDER CAP that has terminals spaced farther apart so the spark energy can't jump to the wrong terminal...
The third part of this,
Getting GOOD BRASS TERMINALS in the distributor cap!
When high voltage electricity discharges hit aluminum,
The discharge BURNS A 'TUNNEL' into the aluminum, turning that aluminum into aluminum OXIDE (Corrosion),
And we all know how well corrosion conducts electricity! (IT DOESN'T!!!)
So, what we are aiming to do is,
Use the 'Ford' version of the Distributor Cap, Rotor, Plug Wires, ect. for this (Ford) 'Motorcraft' distributor...
Now, AMC/Jeep *SHOULD* have used the 'Ford' design with this ignition in the first place...
I don't know the reason WHY they didn't (I suspect cost or patent design issues),
But YOU Can upgrade your ignition to work MUCH better for the cost of 'Tune Up' parts, the stuff you have to change about once a year anyway,
So there is ZERO cost increase and ZERO maintenance costs above what you *Should* normally be spending on your Jeep with this UPGRADE,
And trust me, it's an 'UPGRADE' in every way!
CAP ADAPTER, CAP, ROTOR are all from an '82 Ford F-150 Pickup With 300 CID I-6 Engine...
CAP ADAPTER, SCREWS TO DISTRIBUTOR.
CAP ADAPTER, ROTOR IN PLACE ON THE FACTORY DISTRIBUTOR,
This is a TWO SCREW operation! (rotor is pointing at #1 Plug Terminal Location)
Upgraded Distributor Cap & Rotor,
YOU NEED A GOOD SET OF PLUG WIRES!
You can spend around $45 for a set of 'Off The Shelf' wires for a Ford F-150 Pickup Truck with 300 CID I-6 Engine that will 'Work', but not be the best you can use...
And expect to replace them again in about 5 years,
Or you can spend around $90 ON A TOP QUALITY SET OF WIRES FOR YOUR JEEP...
MSD makes a 'Cut To Fit' set that will allow you to have wires that ACTUALLY FIT YOUR JEEP,
Will live for more than 10 years, will 'Snap Lock' onto your plugs and cap, and will have boots that with a little dielectric grease around the wires/terminal sockets, will be WATER PROOF...
GENERIC, '82 Ford F-150 Pickup with 300 CID I-6 Engine.
MSD 'Blue Color, Cut To Fit' wires, MSD p/n
MSD 'Black Color, Cut To Fit' wires, MSD p/n
MSD 'Red Color, Cut To Fit' wires, MSD p/n
THIS IS A 'GENERIC SET' of 'Off The Shelf' wires and they are WAY too long, have wrong boot angles, ect., but it's what the 'Customer' wanted to use...
About two months after this install, the Jeep started popping through the exhaust and misfiring,
Those wires wound up in my trash barrel, and we installed a set of MSD Cut To Fit wires and no problems since...
DON'T FORGET THE DETAILS!
Shoot some dielectric grease into the groove under the distributor cap!
This will help seal up your distributor from moisture!
OPEN UP THE PLUG GAP!
The better current path will support larger plug gaps which produce higher discharge Voltages.
You should open the plug gap up to about 0.045".
Don't forget the 'Never-Seize' on the spark plugs!
This REALLY helps the plug maintain an electrical 'ground' to the engine block and prevents rust in your spark plug hole threads!
POST 2, V-8 Engines, AMC 304, 360, 401 From '78 to '90, 'TeamRush' Upgrade.
The Jeep Factory Ignition from '78 to '90 on AMC V-8 engines is a 'Ford' type Motorcraft Distributor and a 'DuraSpark' module.
The distributor is,
VERY Strong Trigger Signal,
And all around a good choice for your vehicle.
Where AMC/Jeep dropped the ball was using the 'Ford' electronic ignition with a small cap, rotor and lousy plug wires...
The 'TeamRush' upgrade simply corrects the biggest issues this particular ignition system had by using the better designs 'Ford' used with the very same ignition.
V-8 Owners have more concern with a good ignition than I-6 owners do, simply because they turn higher RPMs than most I-6 owners ever will...
And as the engine RPM speed increases, the effectiveness of the Single Spark Ignition System fails miserably to keep all cylinders firing when they are supposed to.
CAP & ROTOR are the biggest issues with a Jeep 'Factory' ignition.
The SHORT ROTOR allows the spark energy to jump to electrical 'Ground' inside the distributor housing, so you don't get ANY spark at the spark plug.
This is called 'Ground Fire', and it causes a dead miss at the cylinder when it happens.
The SMALL DIAMETER of the distributor cap allows the spark energy to 'Jump' to more than one plug wire terminal at a time.
If it jumps to the cylinder BEHIND the one that's supposed to be firing, you just loose that spark energy to a cylinder on 'Exhaust' stroke,
But if that spark energy jumps to the NEXT CYLINDER IN THE FIRING ORDER,
You are firing that cylinder 90 crankshaft degrees too soon!
That can cause some SERIOUS problems with valves, pistons, connecting rods and rod bearing, and with crank & crank bearings!
What 'Ford' did when they introduced the 'DuraSpark' ignition was to use a MUCH taller/wider distributor cap and taller rotor.
The taller rotor helps keep the 'Ground Fires' from happening,
And the wider cap spaces the terminals out farther to keep Multiple Cylinders from being fired at the same time and Cross Fires from happening...
ALL YOU ARE REPLACING IS 'WEAR' OR 'CONSUMABLE' PARTS.
Stuff you need to replace once in a while anyway, so the 'Extra Cost is ZERO.
Since you have to replace this stuff anyway, the extra work/maintenance is ZERO.
This is an UPGRADE in every way!
THIS UPGRADE REQUIRES A LITTLE FABRICATION...
V-8 DISTRIBUTOR UPGRADES WILL NEED A DIFFERENT ALIGNMENT TAB FOR THE UPGRADED CAP!
This is VERY easy to do, I usually use the side of a pop can, a razor knife or tin snips and needle nose pliers...
These are graphics showing what the alignment tab looks like, were it goes on the distributor to keep the cap adapter in the correct location.
The screw hole is in EVERY Jeep/Motorcraft distributor, so there is no drilling or threading on the distributor,
You simply cut/fold the tab and install it.
The WIDTH of the tab is found on the cap adapter slot it fits in,
You want to make the metal tab 'Tight' in the slot so the cap adapter/cap doesn't rotate on the distributor body...
CAP ADAPTER, DISTRIBUTOR CAP, ROTOR,
FROM A '79 FORD F-150 PICKUP WITH 302 (5.0L) V-8 ENGINE.
(Part numbers change, application never does, so order for the above...)
These parts drop right on your distributor, you don't even need tools! It's that easy!
THE 'FORD' CAP ADAPTER, CLIPS TO THE DISTRIBUTOR IN PLACE OF YOUR CURRENT DISTRIBUTOR CAP.
(shown up side down in this picture for some reason...)
CAP WITH BRASS TERMINALS AND ROTOR ARE RECOMMENDED!
MSD MAKES THE BEST DISTRIBUTOR CAPS I'VE EVER USED,
MSD p/n 8414 for the 3 piece set, about $36 Retail.
Now, for CAPS, PLUG WIRES, MISCELLANEOUS...
You have a couple of choices,
You can find a set of off the shelf 'Import' wires that usually last somewhere between two months and two years... Usually cost around $45 to $50 a set,
IF YOU DO ANY IGNITION WORK AND DON"T USE A BRASS TERMINAL DISTRIBUTOR CAP AND GOOD PLUG WIRES, YOU ARE WASTING TIME AND MONEY!
MAKING THE SPARK ENERGY, THEN LETTING IT FIZZLE OUT OR JUMP TO 'GROUND' SOMEPLACE DOWN THE LINE BEFORE IT GETS TO THE PLUGS IS A TOTAL WASTE OF TIME & MONEY.
The BIGGEST defect all the small/short distributor caps from the factory had was they allowed the spark energy to jump to the WRONG CYLINDER, Jump to 'Ground', and the plug wires are about worthless.
Upgrading to the 'Plug Tower' type caps with brass terminals, getting the rotor up off the distributor shaft and away from the housing so the spark energy MUST go to the plug is all good,
But if you don't provide a good plug wire to get that spark energy to the spark plugs,
It's a total waste of time and money.
For my money, there is no better plug wire on the market right now for a street or trail driven vehicle than MSD.
(NOT the 'Street Fire' series, but the regular high quality plug wires sets)
I USE A LOT OF MSD p/n 31199 'Blue' WIRES WITH GREAT SUCCESS. BEST TERMINALS, WIRE, BOOTS ON THE MARKET RIGHT NOW. About $90
I ALSO USE A LOT OF MSD p/n 31193 'BLACK' WIRE SETS
AND I USE A LOT OF MSD p/n 31189 'RED' WIRE SETS
THESE ARE 'CUT TO FIT' SO YOU GET AN EXACT FIT,
THE PLUG BOOTS WILL BEND UP TO 90 DEGREES TO GIVE YOU AN EXACT FIT,
AND THE TERMINALS ARE EASY TO ASSEMBLE,
THE CRIMPING TOOL COMES WITH THE WIRE SETS,
TWO SETS OF CAP BOOTS FOR SOCKET OR SPARK PLUG TOWER TYPE TERMINALS,
AND THEY HAVE GOOD INSTRUCTIONS.
$90 SEEMS LIKE A LOT OF MONEY, BUT THESE WIRES HAVE BEEN IN MANY VEHICLES FOR OVER 10 YEARS WITHOUT ANY ISSUES, SO THAT'S ABOUT $9 A YEAR FOR POSITIVE SPARK ENERGY TO THE PLUGS!
DO NOT FORGET THE 'NEVER-SEIZE'!
'Never-Seize' helps make the ELECTRICAL contact between plug & head 'Ground',
Helps keep the plug threads from rusting into the head,
And generally makes your life easier all the way around!
A bead of Dielectric grease in the groove under the cap will help keep water/moisture out of your distributor, so that's ALWAYS a good idea,
And a little dielectric grease in both sides of the plug wires boots, both wire and terminal, will help keep those wires virtually water tight, along with keeping the boots from baking to the plugs.
YOU CAN EASILY open the plug gap to about 0.045" now and drive the coil discharge voltage up.
Since you now have control of the spark energy in the cap/plug wires, your ignition system can support higher voltage/amperage, so there isn't any reason not to.
I'd advise against going past 0.045", you don't want to drive the coil voltage up TOO MUCH and start frying coils and modules!
The 35,000 to 45,000 volts you will now be getting will fire ANY Gasoline engine reliably, so no reason to drive the voltage up any further.
POST 3. Replacement Module Failure & How You Can Fix It.
We all know the "Discount Parts Sores" don't carry 'Factory' replacement parts.
Most times, the stuff you get from a 'Discount Sore' is 'Imported' from someplace that doesn't understand English Measurements, Can't Harden Steel, Can't make an electrical component that will live like the 'Factory Quality' units did...
Because most of our 'Replacement' ignition modules are made in South Africa, China, India you simply can't get one that will work or live like the 'Factory' unit did....
To get around this issue,
I have put together a couple of ways to use a more reliable aftermarket module in place of your constantly failing 'Replacement' modules.
There are TWO versions,
One is the John Strenk's "Stealth HEI" module used in the case if your 'Replacement' module that failed.
This WILL pass emissions testing, both visual and tail pipe.
The second is a stand alone module based around the GM Style HEI module that is around $20-$25 most places.
VERSION 1, John Strenk's Version of the "STEALTH HEI MODULE".
You start with the basic 4 pin GM style HEI module used in everything GM from about '74 to the mid '80s.
I use a '79 Impala with V-8 engine for my ordering purposes.
You will need a tube of 'Heat Transfer Paste' from Radio Shack or a computer store.
Radio Shack p/n 276-1372, about $3.
DO NOT use the Clear 'Dielectric Grease' supplied with most modules, it simply does NOT work well enough for this purpose.
While you are at 'Radio Shack', order Diode, p/n 276-1661, OR, 276-1143, about $1.50
Take your 'DuraSpark' module out of the Jeep,
WRAP YOUR WIRES/CONNECTORS WITH A WET RAG,
Throw it in the oven for about 30-60 minutes at around 200-300 degrees to soften up the potting material used to water proof the electrical circuit board...
Pry the guts out of the old module case, taking care NOT to break or tear up the wiring/connectors, you are going to reuse the wiring.
Once the 'Guts' are out of the module, salvage as much of the wiring as you can off the old circuit board and discard the old circuit board.
*IF*... You have a NICE FLAT CLEAN spot in the module case, you can attach the HEI style module to your case.
You want to clip off the two little round locating tabs on the bottom of the HEI module so it will sit flat on your 'Heat Sink' material, in this instance,
The old module case.
If your case IS NOT flat inside, you will have to find aluminum, copper, so something that will conduct heat away from the module that is FLAT and you can cut to fit in the case...
Once you have the HEI module situated in the old case where you can get connectors on it's terminals, mark the mounting holes in the module and drill the case for some screws...
Use some Heat Transfer Paste under the module when you mount it with screws!
Without the paste, the module won't transfer the heat it produces and burn up quickly!
Connect your wiring as shown in this diagram to the HEI module, and you are done!
Simply install the module where it came from and plug it back in.
That's all there is to the 'Stealth HEI' module swap!
IF YOU DO NOT HAVE A FLAT SPOT INSIDE THE CASE, AND SOME CASES ARE NOT FLAT INSIDE...
Then you will need a 'Heat Sink' surface.
A piece of flat aluminum, copper, something you can fit into the case for the module to rest FLAT on.
This is an example of a module mounted on copper for a heat sink.
Cut the heat sink to fit in the old 'DuraSpark' case and you are off to the races!
(I DON NOT recommend you drill out the factory rivet holding the 'Blue' wire grommet like I did here, Leave it attached to the case...)
DO NOT let your un-insulated terminals touch the case or heat sink!
Your best bet is to use 'Heat Shrink' to insulate your push on terminals!
One 'Grounded' wire can cause no end of troubles!
The MOST Powerful Upgrade You Can Do COST EFFECTIVELY And Easily At Home Is A CDI MODULE.
CDI = Capacitive Discharge Ignition.
Your standard 'Factory' style ignition systems can only supply about 12 volts (or less) to the ignition coil, and most get less than 12 volts in Jeeps...
This SEVERELY LIMITS the ignition coil's ability to 'Charge' in time to fire the next cylinder.
(Charging is called 'Saturation Time', While the actual firing of the plug is called 'Discharge' time)
With 12 Volts or less to the ignition coil, the coil is VERY SLOW to 'Saturate',
And that increases the 'Discharge' times since the coil has to work up enough Voltage/Amperage to jump the spark gap at the spark plug.
What a CDI Module does is store up a bunch of electrical energy in storage devices called 'Capacitors',
The discharges that electrical energy to the ignition coil.
As a result, the coil 'Sees' 400 to 600 Volts, Greatly Reducing it's 'Saturation' times,
And GREATLY INCREASING it's Discharge Voltage/Amperage to your spark plugs.
The 'Saturation/Discharge' times are reduced so much that Multiple Discharges at the plugs are possible, up to SIX Full Power, Full Voltage, Amperage & Duration Discharges are possible at the spark plug for each firing cycle...
Where your facotry 'Single Fire' ignition is giving you ONE weak spark,
The CDI units will give you SIX FULL POWER/DURATION sparks in the same firing cycle window,
(About 20 Crankshaft Degrees).
This makes SURE your fuel/air mixture gets lit correctly, even when the cylinder isn't 'Optimum',
When you have oil leaking into the cylinder past worn rings or valve guides,
When the fuel mixture is a little 'Rich' or 'Lean',
When you have some Exhaust Gasses still in the cylinder,
When it's humid, cold, the engine is excessively warm and cooking the fuel/air mixture...
All in all,
Once you have UPGRADED the cap, rotor, plug wires described above so the extra spark energy can actually REACH the plugs,
The CDI module is the single best money you can spend on your vehilce.
It's compact, easy to install, reliable, but most importantly POWERFUL!
Gas prices aren't getting any cheaper, so why not get the 'BANG' you paid for each and every time those cylinders were supposed to light?
The CDI module will increase your spark energy a bare minimum of 600%, and up to 1,000% depending on what RPM you intend to run!
A CDI (Capacative Discharge Ignition) module will fire your spark plugs about 6 times during each firing cycle, while the above ignition system will only try to fire the plug ONCE.
That's a 600% increase in spark energy right there!
The CDI modules also increase the Duration of the spark, the time the spark 'Lingers' in the spark gap, and the CDI modules increase the Amperage of the spark, Amperage is the 'Heat' of the spark.
With a CID module, there is no question you WILL get the cylinder lit each and every time it's supposed to!
There is no better money you can spend on an Ignition System Upgrade than a CDI module. PERIOD.
DISTRIBUTOR CAP, BRASS TERMINAL OR YOU ARE WASTING TIME AND MONEY...
MSD p/n 8414, THE VERY BEST V-8 CAP KIT ON THE MARKET, ABOUT $36
THIS LITTLE ADAPTER LETS YOU PLUG YOUR JEEP/MOTORCRAFT INTO THE MSD CDI MODULE WITHOUT CUTTING WIRES, IT ADAPTS MOTORCRAFT TO MSD AND KEEPS THE TRIGGER POLARITY CORRECT. MSD p/n 8869
THIS EXTENDS THE RANGE OF THAT MSD DISTRIBUTOR CONNECTION 6 FEET SO YOU CAN MOUNT THE MODULE SOMEWHERE 'SAFE'... MSD p/n 8862
THIS WIRING DIAGRAM WORKS FOR BOTH I-6 & V-8 ENGINES.
TWO COIL OPTIONS ARE SHOWN, CHOOSE THE COIL YOU WANT TO USE AND INSTALL ONLY ONE.
NAPA p/n for coil connectors shown in diagram next to coil type.
This also takes the load of the ignition off your factory wiring which is 25+ years old.
Sometimes, you will get 'Run On' when you shut down the key switch, and the 'DIODE' shown at the bottom of the image above will need to be installed in the 'Excite' wire of the alternator.
Diodes will have a 'Stripe' to indicate which way they should be installed, and the 'Stripe' should face the alternator to solve the 'Run On' problem...
POST 5, MAKING YOUR IGNITION MORE OFF ROAD READY AND EFFICIENT.
The best thing I can tell you for ANY IGNITION is to use QUALITY PARTS,
Brass Terminal Distributor Caps,
Brass Nose Rotors,
Tall Rotors & Wide Caps,
Good Plug Wires....
Make sure your ignition module is SECURELY ELECTRICALLY 'GROUNDED' so it can Make/Break the coil primary circuit,
The Module 'Ground' wire is the 'Black' wire between distributor and module, so splicing in a dedicated 'Ground' wire is HIGHLY RECOMMENDED if you are using a factory style module or a "Stealth HEI" Replacement.
Make sure you engine heads are SECURELY ELECTRICALLY GROUNDED so the spark plugs can get a good 'Ground',
IF your 'Ground' attaches to the block instead of the heads, run a DEDICATED GROUND WIRE to the Head(s).
Make sure you use Copper Based (or at least Zinc based) 'Never-Seize' on the plug threads so they have a good electrical 'Ground' connection to the heads,
And the plug threads in the head don't rust up and break your Electrical 'Ground' connection to the plugs.
Specific tips would be,
1. Use Dielectric grease around the wires in the plug and cap boots to keep the spark from escaping to the closest 'Ground' or another plug wire,
This also water proofs the wire to boot connection.
Actually work it in between the wire and boot, not just a bead heaped up on the end of the boot...
2. Use Dielectric grease in the plug/coil boots to stop corrosion, and to keep those seals water proof.
3. Use Dielectric grease in the groove on the bottom edge of the distributor cap.
This keeps water out and still lets you remove/re-install the cap as many times as you see fit without problems getting it on or off.
4. COAT your vacuum advance arm with some oil (like 3-in-1 oil) and shoot some silicone gasket maker in that hole to plug it up.
The oil will keep the sealer from sticking to the vacuum advance arm and allow it to operate,
While the sealer will close up that big hole in the distributor body.
5. Use some Silicone Sealer or Weather Strip Adhesive to stick the cap adapter to the distributor body.
This plugs up a HUGE leak that can let water into your distributor and cause a shut down when you try and 'Swim' your Jeep.
You don't take the cap adapter off the distributor unless something SERIOUSLY goes wrong, so seal it down tight!
6. Pull the vent out of the top of distributor cap,
Install a MIG welder tip in the hole so you can hook up an air pressure line.
With air pressure, you can run that distributor under water and it will run happily along while blowing bubbles!
The only 'Warning' is to use a NON CONDUCTIVE hose to the MIG welder tip/pressure nipple,
And DO NOT touch the nipple while the engine is running!
If you touch the nipple, YOU are the 'Ground' for the ignition, and you WILL get zapped!
7. If you don't have 'On Board Air' for an air pressure source,
Try a 'Bait Bucket Aerator Pump' that runs on batteries.
These little pumps produce enough pressure to keep water out of your distributor and they are CHEAP to buy/operate on the rare occasions you will be deep water fording.
You WILL have to drill the MIG welder tip out a little for the little pump to work, but that's not an issue to keep from 'Swimming' out of some big mud pit...
8. ANYTIME you have an electrical connector apart, FILL IT WITH DIELECTRIC GREASE before you plug it back in!
If it 'Squirts' out when you plug in, just smile and wipe off the excess...
Squirting out means you have ALL the air spaces filled inside and where grease is, WATER AND CRUD CAN'T BE!
No water and crud = NO CORROSION to screw up your day :grin !
9. Once you have upgraded your ignition, you won't need NEARLY the fuel you were using before.
Take time to lean out your fuel mixture a little and save yourself some money!
A good ignition will fire a LEAN mixture MUCH BETTER than a weak ignition will, so you don't have to over fuel anymore to compensate for a weak ignition.
10. DON'T FORGET TO OPEN YOUR PLUG GAP UP TO AROUND 0.040" or 0.045" now that your distributor and plug wires can handle the extra spark energy!
Opening up the plug gap will force the coil to produce more spark energy, but don't get carried away, I've never seen a gasoline engine that required more than a 0.045" plug gap,
And if you go too far, you will start having problems with the stock ignition coil and module...
But 0.040" to 0.045" is 'Safe' for stock components.
11. If you switched to an HEI module ("Stealth HEI" or "Stand Alone HEI" module swap/conversion) Then switching to an 'E-Core' coil makes a lot of sense and will gain you spark energy.
The HEI style module is designed to work with the E-core type coils rather than 'Stock Jeep Factory' coils, and switching will gain you some spark energy.
Doesn't matter if you switch to the GM style of 'Remote' E-core or the Ford Version of E-core, or most of the aftermarket E-core coils, they are all about the same winding ratios and output energy.
Ford's Version of E-Core on LEFT,
Stock 'Canister' Coil on the RIGHT.
I use the 'Ford' version of the E-core coil, and most of what I use come from Salvage Yards.
You can find the VERY good quality of E-core coil in the salvage yards in anything 'Ford' from about '86 well into the '90s,
Raise the hood, find the coil wire on the distributor, and follow it back to the ignition coil...
Take the coil, coil bracket and coil connector with as much of the 'Little Wires' as is feasible.
This "Salvage Yard" version will run you between $5 & $15,
While if you buy it new, the coil is going to be around $50+ and the connector (NAPA p/n ICC1) will run you about $15+...
The brackets are virtually impossible to find on the aftermarket, so you may have to make your own or beat feet to the salvage yard anyway!
IGNITION 'SECRETS', THINGS YOU WON'T FIND EASILY ANYWHERE ELSE...
The 'Mad Scientist' Nikola Tesla was the first person to design/patent a working high voltage ignition system for automotive use. The "Electrical Igniter For Gas Engines", patented in 1898 is still the same basic system we use today.
The heart of ANY ignition system is the 'Step Up' TRANSFORMER COIL.
The electrical principal of "Electromagnetism" is used here...
Electromagnetism is the 'Electro-Magnetic Link.
Any time an electrical charge is run through ANY conductor, it creates a magnetic field.
The magnetic field will remain STABLE as long as the current runs though the conductor.
To Prove it to yourself, Wrap a bolt with EVEN AND STRAIGHT rows of INSULATED wire,
Then apply battery voltage to the ends of the wire.
You will be able to pick up ferrous metal objects with the bolt as long as the electrical current flows.
Any time a MAGNETIC FIELD MOVES (not stable, but MOVING) through a conductive material, it will produce an electrical current.
To prove this to yourself, Make a TWO Loops of INSULATED wire, several turns each,
Then Connect the two together to make one large circuit.
Put a magnetic Compass in the middle of one of the loops
(Compass perpendicular to loops, loops standing up, while compass lays flat in the center)
And pass a STRONG magnet over the other set of loops.
Current produced by the MOVING MAGNETIC FIELD across the loops at one end will make the compass jump as the current transfers to the other end and creates a magnetic field around the compass...
IF you have a volt meter sensitive enough, you can make ONE LOOP, and connect to the volt meter and watch it jump when you pass the magnetic field though the loop...
Winds of wire with electrical current create a Magnetic field,
While MOVING magnetic fields through a conductor coil create an electrical current.
The act of passing the magnetic field through the coil of wire INDUCES the wire to create an electrical field (INDUCTION),
Induction is what causes your distributor trigger to produce a trigger 'Signal',
Induction is what causes your alternator to make electrical current to charge the battery,
Induction is what makes your starter and blower motor run...
MORE ON ELECTRICAL INDUCTION BELOW IN POST #10...
An electrical 'Transformer' takes advantage of this Electromagnetic Principal.
An iron core, a SECONDARY WINDING (coil) of wire around the core that produces HIGHER voltage than the input voltage,
And a PRIMARY WINDING (coil) of wire around the Core & Secondary Winding.
When the PRIMARY WINDING is charged with electricity,
That coil produces a STABLE MAGNETIC FIELD.
The Iron Core focuses and centers that Magnetic Field.
When the electrical current to the Primary Winding is cut off (open circuit),
The Magnetic Field collapses (Moves) on the Iron Core.
When that Magnetic Field Collapses (Moves) through the Secondary Winding, it produces an electrical current.
The HIGH VOLTAGE electrical current we use to fire spark plugs is created when the MAGNETIC FIELD COLLAPSES THROUGH THE SECONDARY WINDING.
The Ignition Coil 'SATURATES' Magnetically when the Primary Circuit Winding has current running through it...
(When breaker points are 'Closed' and complete the circuit, or when an ignition module 'Closes' and current runs through the Primary Windings)...
And the ignition FIRES when the primary winding circuit is OPENED,
Breaker points OPEN, or the module OPENS the Primary circuit,
And the Magnetic Field collapses through the secondary windings, INDUCING an electrical current in that Secondary coil of wire.
As the magnetic field created by the Primary winding collapses through the Secondary Winding,
The energy expended by the Primary Winding making the Magnetic Field,
When that Magnetic Field Collapses, if there weren't any losses, would INDUCE 100 to 150 times the energy it took to make the primary magnetic field.
In our case, the coil produces about 35,000 to 45,000 Volt from a 12 volt source
(after losses from interference with magnetic field, resistance losses in the windings/connections, ect.)
Now, it takes TIME to build the magnetic field when the Primary Circuit is closed.
The 'Saturation' time we talk about for automotive ignitions is MAGNETIC SATURATION,
Waiting for the magnetic field to build to full strength and stabilize.
The second time we talk about is 'Discharge' time.
The time it takes the magnetic field to collapse through the secondary windings, and the current potential in the secondary windings to collect/increase enough to overcome the air gaps in the rotor to distributor cap gap, the gap at the spark plugs, ect.
The electrical 'Potential' has to build up to overcome the gaps in the 'Ground Path'.
The ground path in our case is the 'Spark Plugs' if you do everything correctly...
It takes TIME for the air in the gaps to ionize so the actual electrical discharge can happen...
Then there is 'DURATION' of discharge at the gaps.
The time the spark LINGERS in the rotor/cap and plug gaps.
The longer the 'DURATION' of discharge, the better chance you have of getting the fire lit in the cylinder...
Then the third part of 'Spark Energy' is Amperage, or VOLUME of electrical current the secondary windings will produce.
The larger the wire in the secondary windings, and the more turns in that winding, the more Amperage you will get at the plug to produce 'HEAT' to get the fire lit.
Now, you have the 'Basics'...
Voltage to get the gaps ionized and start the electrical discharge to 'Ground',
Amperage that determines how 'Hot' the spark is going to be in the plug gap.
Duration that determines how long that spark is gong to linger in the plug gap.
The LONGER it takes to make voltage to jump the gaps in the system,
The LESS DURATION you will have at the plug gap to get the fire lit.
Opening your plug gap WAY up drives up Voltage,
But seriously cuts back on your Duration & Amperage since that Magnetic Field Collapse happens at the same speed no matter what you are running your plug gaps at...
The ONLY time the Secondary Windings can produce electrical current is when the Magnetic Field is MOVING though them, and trust me, magnetic fields collapse REALLY QUICKLY!
So the more you drive up the voltage over what you ACTUALLY NEED, the more you steal from Amperage and Duration.
35,000 Volts to 45,000 volts will fire ANY GASOLINE ENGINE with anywhere near a proper fuel ratio in the cylinders.
It takes a little more voltage to fire 'Exotic' fuels, like Propane, Alcohol, ect., but your (normally carbed) gasoline engine will fire completely reliably at 35,000 to 45,000 volts.
A 0.040" to 0.045" plug gap will force the ignition coil to produce about 40,000 to 45,000 volts,
And still have time to produce "Somewhat Reasonable" Amperage and Duration at lower RPM.
As engine speed increases (RPM Rises) the time the ignition coil has to Magnetically Saturate and Discharge is cut WAY back... So common 12 volt input to the coil simply isn't enough to put out full strength Spark Energy...
This brings up TWO ISSUES...
1. UNREASONABLE SPARK GAPS.
Every time I see an advertisement for 0.050" or 0.055" (or even 0.060") spark gaps at the plugs, I CRINGE!
With spark gaps that large, you are driving the Voltage so far up before discharge across the plug gaps you are virtually eliminating any Amperage or Duration of spark discharge at the gap.
You get a COLD, QUICK spark that doesn't light the fire in the cylinder correctly,
2. You are driving the Voltage up so far you are seriously in danger of blowing through the insulation INSIDE THE COIL IT'S SELF!
When a coil discharges internally (spark jumps to 'Ground' inside the coil casing) you are burning up windings you will need later!
The more it discharges internally, the larger the 'Hole' you make in the insulation, and the more likely the spark energy is going to seek that path to 'Ground' instead of firing you plugs,
And the more windings you are damaging so the coil has to work even harder to produce Spark Energy...
So when you see some advertisement for "50,000 Volts" or "70,000 Volts",
Think to yourself, "Yup, 50,000 Volts for 50 Miles instead of 35,000 volts for 200,000 Miles!"
Now, Spark Energy Compared To Crank Shaft Rotation...
You have about 20 crank shaft degrees of rotation to fire a spark plug in time to produce ANY power...
Fire too soon, you try to hammer the piston down on the crank damaging valves, pistons, rods, bearings and the crank it's self.
Fire too late, and you get NOTHING in the way of power from the cylinder.
There is a 'Sweet Spot' of about 20 crank shaft degrees to get the fire burning so it will travel across the combustion chamber and produce pressure to push the piston down AFTER the crank passes the Top Dead Center point in rotation.
If you are VERY lucky, you fire the cylinder at all!
With a single spark ignition and relatively weak spark discharge,
You get ONE TRY to get that cylinder to light the way its supposed to and produce a flame front across the cylinder.
You TRY to fire that cylinder soon enough to get the fire started, so peak pressure from the combustion is reached right after the crank rolls over Top Dead Center...
This produces the most power for the fuel you burn.
There are ALL SORT OF OBSTACLES TO THIS PROCESS!
Oil in the combustion chamber from leaking valve guides or piston rings,
Exhaust gasses that didn't evacuate during the exhaust stroke are still in the chamber,
Rich fuel or Lean fuel pockets are all over the chamber,
Moisture in the air,
Cold combustion chamber/engine will cause problems,
Bad electrical 'Ground' to the engine that inhibits the spark discharge across the plug gap,
Low voltage to the ignition coil or a failing set of breaker points or ignition module cutting the saturation times short,
Speed of the crankshaft leaving very little time for the spark energy to discharge in the plug gap...
And in a spark plug that might be facing the wrong direction to get the flame front started correctly, and it's a wonder we fire any of these cylinders at all!
So things like making SURE the module that 'Grounds' the Primary Cirucit of the coil has a SOLID 'GROUND' is a VERY good idea.
A 'Weak' 'Ground' connection will rob your ignition coil, the better the current can flow through the PRIMARY side of the ignition, the faster and stronger the magnetic field will form and saturate.
Making sure you have a solid 'Ground' to the engine heads is always a good idea.
Without a solid 'Gound' connection, the plugs CAN NOT give a good path for the spark energy to discharge in the gap of the plug.
Making sure you use 'Never-Seize', especially COPPER BASED 'Never-Seize' on the plugs will ensure they get a good 'Ground' to the engine heads,
And 'Never-Seize' is a good rust preventative to keep that head to plug connection working well for a long time.
BRASS terminals in the distributor caps, BRASS noses on the distributor rotors will help get the spark energy through the distributor cap.
BRASS doesn't erode/corrode like aluminum or steel does in the face of the spark energy discharges,
So they will live MUCH longer and do a better job than aluminum/steel will in that application.
Steel gets the carbon burned out of it when the high temperature discharges happen, and that leaves deep holes to corrode in the metal.
It's even worse in aluminum,
High voltage/high temperature discharges in aluminum burns TUNNELS in the aluminum, turning the aluminum into aluminum oxide when it corrodes,
Aluminum Oxide is a LOUSY electrical conductor.
Brass 'HEALS' it's self when overheated, and it corrodes VERY SLOWLY compared to steel or aluminum.
Brass terminal caps may 'Seem' expensive, but for $5 more you are getting a cap that you will be able to clean off the corrosion and use for YEARS instead of months...
The same is true with brass noses on the rotors.
SPARK PLUG WIRES are the biggest thing I see done wrong!
Spark plug wires sold as 'Replacements' are VERY poorly constructed, lousy conductors, lousy insulation, lousy boot material, lousy connectors...
'Replacement' wires from the 'Discount Auto Parts Sores' often run $45 to $55, and they are usually good for MONTHS,
While a top quality set of spark plug wires will have GREAT conductors,
They will have 'Snap Lock' terminal ends made of stainless steel that will SECURELY make electrical contact and last for years.
They will have a high temperature, double layers of insulation made of silicone, virtually impervious to heat and under hood contaminants.
They will have good sealing/insulating cap and plug boots that are virtually indestructible.
The 'Cut To Fit' sets of MSD wires have all the above good qualities,
Plus they have 'Bend To Fit' connectors/boots at the plugs so you get a PRECISE fit,
And they usually last about 10 years or more in a street driven vehicle.
They are expensive, around $90 a set now, but worth EVERY PENNEY to get your hard fought for spark energy to the spark plugs where it can do some good!
I WILL NOT use the MSD 'STREET FIRE' Components.
They are 'Import' and I've had no luck with them at all.
Go with the regular plug wire sets from MSD and you can't go wrong!
Now that we have gone over all the parts of spark energy, and how to get it to the plugs,
Lets talk a little about MAKING SPARK ENERGY AT THE PLUG GAP...
As stated above, the CDI modules are the "NEXT GENERATION" of ignition modules.
They are a bolt on order of magnitude increase in spark energy.
For about 80 years, the standard 6 volt or 12 volt ignition coil standing alone has fired our ignitions.
Mostly because it was cheap to produce, easy to work on, and there was simply nothing out there better for the application.
SOLID STATE ELECTRONICS, namely the 'Transistor' came along and changed that.
First it was used to get rid of breaker points, a HORRIBLE mechanical/electrical device that wore constantly, was unstable, and had to be used because there wasn't anything better out there.
The transistor switches the power to the primary side of the coil MUCH cleaner, allowing for longer saturation times,
It allowed for full current to reach the coil, since breaker points need reduced voltage to keep from burning up the contact surfaces,
And it never needed conventional 'Tuning' like breaker points CONSTANTLY did.
You were still limited to 12 volts to the ignition coil because that's what the vehicle had available...
Then along came the CDI module.
Electrical current could be 'Stored' in Capacitors and thrown at the ignition coil to increase PRIMARY voltages!
Now you could CLEANLY switch 400 to 600 volts to the coil (at very low amperage) and get a MUCH FASTER magnetic saturation time,
Along with a VERY CLEAN switching system that allowed for greater output from the very same coil.
Between the STRONGER Magnetic Field, the FASTER Magnetic Saturation times, And the VERY CLEAN ON/OFF switching of the primary circuit, you got MUCH GREATER SPARK ENERGY FROM THE COIL, in all three major areas, Voltage, Amperage & Duration in the spark gaps...
This was a VAST improvment over the breaker points or early electronic ignitions by it's self,
There was still ONE AREA you can't change...
The speed a magnetic field collapses through the secondary windings.
Everyone messed with coil designs all though the 60s, 70s, 80s,
More windings, larger gauge wire in the windings, different core material, different coil shapes, more secondary windings, ect.
You could build for more of this or that, but you would rob energy from the other areas,
Increased voltage reduced Amperage & Duration...
And they were VERY SMALL changes when there were changes (Proving Nikola Tesla had the coil winding ratios and wire sizes about right in 1898!)
Since you CAN NOT change the speed at which a magnetic field collapses,
And increasing the turn counts, winding ratios and wire gauge sizes only produce an UNMANAGEABLE size coil... (Ever see one of those old giant yellow 'Super Coils'?)
And all that messing around didn't change things much at all...
But the very clean switching and super precise solid state electronics allowed for something else,
The ability to fire the plug 6 FULL ENERGY TIMES at lower RPM (about 20 Crankshaft degrees).
Multiple Spark Discharge was born! (MSD)
If you have the crankshaft TIME, then why not build/collapse that magnetic field 6 times to make 600% more spark energy at the plug gap?
And that's 6 FULL DISCHARGES, at full value for Voltage, Amperage & Duration!
If you have the Crankshaft time at TDC, why not do it!
That gets you 6 tries to get that cylinder properly lit!
Even if it's slightly late, doesn't light correctly until the second or third or fourth try, it's still lighting in time to make POWER FOR YOU instead of wasting the fuel you dumped in there!
Now, when you crank an engine past about 2,500 RPM, there simply is NOT crankshaft TIME at TDC for you to bang away at that cylinder 6 times,
But I do most all my driving at BELOW 2,500 RPM, so I get 6 tries to actually get some use out of that fuel in those cylinders most of the time!
A 2,500 RPM, when the factory single spark/12 volt (or less than 12 volt) ignitions are weakening since they DO NOT have time to saturate and discharge,
The CDI Module is still throwing a VERY STRONG, VERY HOT, VERY LONG LASTING spark at the plug.
THIS IS THE REASON I SAY THE CDI MODULE IS THE NEXT EVOLUTION IN IGNITIONS.
An electrical current running down a wire will create a magnetic field around that wire.
Now, ELECTRICITY FROM SWITCHING SOURCES (Switching 'ON/OFF'),
Like the contacts in an electric motor making/breaking circuits as the motor spins,
Or like your ignition switching 'On/Off',
Or like your spark plug wires sending spark energy down the wires,
The things will create MOVING CURRENT, Which makes, then lets magnetic fields collapse...
MOVING MAGNETIC FIELDS FROM A SINGLE WIRE...
Making the magnetic field around the spark plug wire as it fires,
Then the magnetic field collapses after the firing cycle is over...
If you have TWO SPARK PLUG WIRES IN CLOSE PROXIMITY, say, less than 1/2" inch,
You stand a VERY good chance of firing a SECOND PLUG at the same time you fire the first plug.
INDUCTION will cause the second plug wire to fire if it's close enough and running together long enough with the first plug wire!
This is DISASTROUS if you fire the wrong spark plug! Just like you were firing a cylinder WAY TOO SOON!
(The 5-7 firing order on small block Chevy comes to mind)
Two long wires, running bundled together, 5 fires on command, fires cylinder 7 about 90 degrees too soon and people wonder why #7 cylinder is the 'Problem Child' in Small Block Chevys!
First off, #5 is sucking up all the fuel/air mixture when #7 starts it's intake stroke, so it's getting a lean fuel mixture,
Then #5 plug wire INDUCES a 90 degree too early firing of the #7 spark plug, and BANG!...
Gaping hole where the piston used to be!
Another prime example of INDUCTION is where you run very low voltage distributor trigger signal wires UN-SHIELDED along with spark plug wires,
(and YES, I've seen them in the same wiring looms, trigger wires zip tied to spark plug wires!)
Distributor trigger sends signal, the module fires the plug wires,
The plug wire INDUCES a second trigger signal in the trigger wires, the module fires the coil again, but WAY TOO SOON, no chance to saturate and way too soon for the next cylinder to be ready to fire...
Another example of INDUCTION is someone running their power wires to the radio or the antenna wire next to the heater motor wires.
Heater motor switches 'On/Off' as the contacts make/brake connection with the windings in the motor,
You get an ANNOYING BUZZ in the radio you can't seem to track down!
The heater wires are INDUCING a current spike in the CONSTANTLY charged wires to the radio, either power consumption or antenna,
So you think is LINE NOISE, so you try connecting the radio directly to the battery (UNSAFE) but they are still too close to the heater motor wires, so you STILL HAVE THE BUZZ!
Then you install a great big power capacitor trying to dampen the line noise (which it IS NOT Line noise),
But STILL the buzz since the wires are STILL too close to the blower motor wires...
And it's INDUCTION instead of Line Noise from switching...
INDUCTION, it does happen, it is real, and it WILL cause problems if you don't get your trigger wires away from the spark plug wires (or any high current load switching wires, like the heater motor),
And it WILL fire spark plugs you don't intend to at the worst possible times if you don't separate the wires with some space!
About an inch will usually do to keep plug wires from induction firing...
And keep your distributor trigger wires well away from the spark plug wires, and next to the engine block or sheet metal!
Metal blocks the magnetic field from doing it's worst, and so does TWISTING the trigger wire pair!
Since the magnetic field strikes BOTH WIRES EVENLY in a twisted pair, the induction often cancels it's self out...
Now, for some of the sillier ideas that have come along...
A CRANK TRIGGER WHEEL, with 4 triggers round one trigger signal core ('Tooth' in Ignition terms)...
Each trigger fires ONE coil with two plug wires.
One cylinder will be on 'Compression' when it fires, the other 'Sister' cylinder will be on 'Exhaust' stroke with it's plug fires...
This system gave me about 4 times as long to saturate the 12 volt coils, since each coil was only firing ONCE a revolution of the engine instead of a single coil trying to fire 4 times a revolution.
It worked OK, but it was a PAIN to keep timed, and you had a STATIC advance, no vacuum or centrifugal advance in a solid mounted system like that with no distributor.
Another try, back in breaker points days, was 8 sets of breaker points triggered by one lobe on the distributor shaft...
8 coils, one for each cylinder, and a single coil wire for each spark plug.
Talk about a tuning nightmare!
It worked GREAT for about 15 to 20 minutes, then like every other set of breaker points...
It started to degrade from electrical burns on the contact faces of the breaker points.
Another issue was the sheer size of the stupid thing!
You think you don't have firewall clearance now, try increasing the distributor diameter about double and see what you get!
Another 'Bright Idea' was to mount the distributor on the front of the camshaft....
WAY more work than it was worth!
And my famous 90 degree distributor... Like you REALLY need to point your distributor side ways?
At least that came in handy later to clear blower drives on front distributor engines...
So now you know WAY MORE about an automotive ignition than anyone should working on an old Jeep, but this will help you understand WHY I recommend the things I do!
I don't care for the 'Digital' CDI units because they have 'Adjustments' and 'Customers' like to mess with ANYTHING that has 'Adjustments'...
For someone that has a LOCKED DOWN distributor, and wants to mess with timing at the module, the 'Digital' with adjustments is a quick way to mess with the timing,
But for the base model of Digital over Analog, there is no difference you be able to detect.
'DIGITAL' simply means there is no 'Ramp Time' in the switching of the transistors,
And the transistors are fast enough in the 'Analog' units you won't see any difference...
"DIGITAL", in this application, means you get a SQUARE WAVE switching.
Where some of the analog switching is a very steep ramp instead of a virtually instant 'On' and 'Off' required for micro processors that handle timing chores, ect.
The 'Analog' versions are probably still produced because so many racing bodies require you have NO COMPUTER CONTROL over the vehicle functions.
No micro processors, just semi-conductor switching...
Now, I KNOW this isn't a real consideration for any practical reasons,
But the ANALOG signal versions tolerate EMP/RFI (line 'noise') better than 'Digital' versions do.
I'm not talking the 'Gloom & Doom' type that are expecting the end of the world,
I'm talking getting some of the switching wires too close to things like spark plug wires, ignition coils, having a brush give up in a blower motor or windshield wiper motor, ect. that makes 'Noise' in the wiring harness.
Some of the 'Digital' boxes are VERY sensitive to the line noise, induction noise, ect. and sometimes you have to be VERY careful about shielding the wiring and what is on the same power line as the digital boxes...
Since I'm the 'Stick EVERYTHING In one bundle type of wiring guy, that's REALLY AGGRAVATING to have 10 different wires runs, all shielded from each other...
Since you aren't going to rev up your engine where you need a 'Billet' distributor housing,
You aren't gong to need those roller bearings in the distributor if you don't hit high RPMs,
And the MSD distributor uses the SAME TRIGGER as the Jeep/Motorcraft distributor, so the MSD isn't any stronger signal, more accurate,
And since we are using the MSD cap in most cases, there isn't an issue with the secondary high voltage side of the Jeep/Motorcraft distributor,
I don't see spending the money on a $350 when a $50 distributor at most (Factory Jeep/Motorcraft Remanufactured) until will work fine for your mostly stock engine.
I mean if you have the money,
You want to go all 'MSD' or other aftermarket company for bragging rights,
Then by all means, spend that money!
MY UPGRADES use the best of the 'Stock' parts,
Aftermarket parts when stock won't do,
And I do these things for the least amount of money we can get by with...
No sense in pissing money away on a 'NASCAR' distributor when you are basically driving a 'Tractor' in compairson.
When you start running 500 mile, flat out races where the engine never gets below 5,000 RPM on the track, and you are going to see 7,500 RPM or more,
It's a REAL GOOD IDEA to get a distributor with sealed roller bearings...
When you are going to chug around under 3,500 RPM most times,
The factory distributor is FINE...
Same trigger as the NASCAR version from MSD, so the trigger is a good string signal,
And once you upgrade cap, rotor, plug wires, the problem Jeep engineered into the system are gone and it's capable of keeping up with higher Voltages, Amperages and Durations without failing...
I don't see any need to go more expensive than the $50 Remanufactured Replacement for Jeep...