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post #1 of (permalink) Old 09-12-2006, 08:33 AM Thread Starter
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AMC Ignition box, do I need it?

I know I need some sort of ignition controller but does the AMC box have any advantage over others? I am getting to the ignition wiring of my ground up CJ build and am wondering if there is any advantage at all to the AMC box. My preference would be to just use a Mopar style controller because I have a couple laying around and they are smaller & cheaper to replace if necessary. Seems like I recall that some AMC units had some built-in timing retard during cranking or some-such and I don't want to lose out om any neato features like that. Ideally I would use an MSD but I'm poor and trying to make this work with what I have "in stock".
Engine in question is a 90 4.2 block with a 4.0 head, Clifford cam, Offy 4V intake and Holley 390.
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post #2 of (permalink) Old 09-12-2006, 08:42 AM
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Re: AMC Ignition box, do I need it?

The ignition module is nothing more than an electronic switch. These are somewhat interchangeable as long as you know how to wire them. Are there advantages/disadvantages to each module in mixing and matching? IMHO, the only one I can think of is the GM HEI module replacement that lets you use full voltage and get rid of the ballast/resistor wire.
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post #3 of (permalink) Old 09-12-2006, 11:25 AM
 
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Re: AMC Ignition box, do I need it?

I actually had one of those AMC boxes. I never notice them being bigger. I wonder if they have more cooling capasity. ??

I had been swapping regular Ford DuraSpark boxes in and out with no problems I noticed. I wonder about the quality of the cheaper replacement boxes though.

I ended up with a GM HEI module in a DuraSpark box.
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post #4 of (permalink) Old 09-12-2006, 05:01 PM Thread Starter
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Re: AMC Ignition box, do I need it?

AMC box is 4 times the size of a Mopar one. Probably the exact same size as a Ford one as
AMC = Motorcraft as far as ignition boxes.
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post #5 of (permalink) Old 09-13-2006, 10:28 PM
 
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Re: AMC Ignition box, do I need it?

John and Leve are headed in the correct direction...

I have a couple of questions for you,

1. Is the module you have now two connectors, one with two wires, one with four wires?

2. What is the compression of your engine?

--------------------------

If the module is the six wire, two connector type, it is the DuraSpark module Motorcraft sold to AMC From '78-'90

The distributor from that system is second only to an MSD roller bearing unit.
They both use the same magnetic trigger, so unless you plan to sustain RPM above 5,000 RPM for long periods of time, you should be fine with the Motorcraft distributor.

Just about screwed the pooch!
You will need the upgrade parts from here,
http://www.junkyardgenius.com/ignition/jeep/jeep06.html
Look at the cap adaptor, cap and rotor upgrade, section one.
-----------
Plug wire recomendation is for a set of premium 4.0 L. from a later model Jeep, like the 95 and newer.

If you care to upgrade the coil, to the Ford style E-core coil,
MSD p/n MSD-8227, $46.88

http://store.summitracing.com/partdetail...15&autoview=sku

OR,

Summit Racing's version of the Ford style E-core coil,
Summit p/n SUM-853011, Price $29.95

http://store.summitracing.com/partdetail...15&autoview=sku

OR,

Accel's version of the Ford style E-core coil,
Accel p/n ACC-140012, Price $41.88
http://store.summitracing.com/partdetail...15&autoview=sku

OR,

Crain version of the Ford style E-core coil,
Crane p/n CRN-730-0391, price $49.88
http://store.summitracing.com/partdetail...15&autoview=sku

OR,

Hypertech version of the Ford style E-core coil,
Hypertech p/n HYP-4064, price $49.95
http://store.summitracing.com/partdetail...15&autoview=sku
---------------

Now, on to the Module issue...

The Module you have now is very good for a high compression engine.
Most high compression engines are running a lot of initial timing, and the 'Crank' timing retard circuit is very good for keeping the engine from 'Kicking Back' on the starter.
The bad part about the DuraSpark ignition is it may need a resistor to keep the module alive, and the wiring in and out of the module isn't large enough to carry the current required to take advantage of the new, high output E-core coils.

I've been running a GM HEI module with a custom built wiring harness (takes about an hour to make) and a relay for power switching for the ignition coil.
Very 'Hot' setup for a stock 12 volt ignition system, and very CHEAP! to build.
I didn't care for the GM HEI distributor, but using the module does have it's benefits.
This module can be wired to feed an E-core coil to it's limits.

I don't use too many Chrysler modules.
I don't care for the module in either switching capability, current carrying capability, or dwell control.
The Chrysler module MUST have a limiting resistor or they will 'Let The Magic Smoke Out'...

Let me know which module/coil you want to use, and I'll shoot you the wiring diagram and specs...
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post #6 of (permalink) Old 09-14-2006, 09:01 AM Thread Starter
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Re: AMC Ignition box, do I need it?

I do have the six-wire AMC module. Compression is stock. I doubt RPM will ever even get to 5000 (3:73's with 33" tires) as this will primarily be a street driven "mall cruiser" Coil will probably be a big ol Accel unit thats been sitting around here unused for a decade or so. Years ago I had a 12 second small block Mopar using Direct Connection's "Chrome" box to drive an MSD Blaster 2 coil with MSD 8.8 plug wires worked great then. I still have several MOPAR boxes about and given the low RPM future planned for this motor figured I'd go with what I am familiar with. I have no clue what Motorcraft is doing with those 6 wires but I am familiar with Mopars wiring scheme.
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post #7 of (permalink) Old 09-14-2006, 09:52 AM
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Re: AMC Ignition box, do I need it?

[ QUOTE ]
...I have no clue what Motorcraft is doing with those 6 wires but I am familiar with Mopars wiring scheme.

[/ QUOTE ]

Now you've got a clue...


Last edited by LEVE; 03-24-2009 at 07:43 PM.
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post #8 of (permalink) Old 09-14-2006, 11:45 AM
 
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Re: AMC Ignition box, do I need it?

[ QUOTE ]
[ QUOTE ]
...I have no clue what Motorcraft is doing with those 6 wires but I am familiar with Mopars wiring scheme.

[/ QUOTE ]

Now you've got a clue...



[/ QUOTE ]

OK Leve. Now I lost my last clue [img]/ubbthreads/images/graemlins/smile.gif[/img]

What is this picture out of?
I dont think "Switcher" on the DS is the same as the "Switcher" on the HEI module.
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post #9 of (permalink) Old 09-14-2006, 07:23 PM
 
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Re: AMC Ignition box, do I need it?


How about this,
Using your Motorcraft Distributor and GM HEI module.
('79 Police or Corvette, 4 pin)



Here is using the factory DuraSpark ignition,



Or you can use your Chrysler module, make sure you keep a resistor in line, and get the polarity to the mag trigger pickup correct.
With Chrysler, they used Gray and Black.

Black to Distributor Violet
Gray to Distributor Orange.

Make sure you keep the distributor mag trigger pair twisted together and away from plug wires.
Metal is your friend, lay them on or against the engine block to the fire wall, and then along the body to the module.
This pair is succeptable to EM & RF noise like crazy, so keep them away from the module or coil power wires also.
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