Here is the new DuraSpark on left and my old Dual Point pulled from motor.
Attachments
Images (1)
Side by side showing MotorCraft stamp...left DuraSpark I right Dual Point from my 72 351C...they are almost identical.
Attachments
Images (1)
Full length view/comparison of DuraSpark on left, old Dual Point distributor on right.
Attachments
Images (1)
Very nice 
thanks for the photos and info,
Cheers, Tim.
thanks for the photos and info,Cheers, Tim.
Hey guys,
I need to make an addendum to what I wrote earlier. The connectors on every Duraspark module are "keyed" differently by Ford so modules cannot be installed in the wrong car. What this means is that the Painless Wiring harness #30812 which is keyed for a Duraspark II module will not work with a Duraspark I module unless 4 changes are made to allow Duraspark I parts to be used with a Duraspark II harness:
(1) The Duraspark II key tab must be removed from the 4 pin connector to use this harness with Duraspark I modules.
(2) The positions of the green wire and the orange wire must be reversed where they are spliced into the four pin connector's wiring.
(3) The ballast resistor included with the wiring harness is not used for a Duraspark I application.
(4) The alignment lug on the Duraspark I coil tower must be removed to allow the Duraspark II horse shoe style coil connector to slide on. It helps to have a Dremel tool.
Its not the end of the world, these changes are easy to make. But I don't want you to have any surprises when your wiring harness arrives in the mail and you find the Duraspark I connector doesn't just slip into the harness connector.
Obviously it would be better to pull a harness from a 1977 - 1979 California car if you want to use the Duraspark I module, but that may be hard to do if you don't live in California.
Sorry I didn't think of this sooner, it's been a while since I've worked on a Ford with a Duraspark ignition.
I need to make an addendum to what I wrote earlier. The connectors on every Duraspark module are "keyed" differently by Ford so modules cannot be installed in the wrong car. What this means is that the Painless Wiring harness #30812 which is keyed for a Duraspark II module will not work with a Duraspark I module unless 4 changes are made to allow Duraspark I parts to be used with a Duraspark II harness:
(1) The Duraspark II key tab must be removed from the 4 pin connector to use this harness with Duraspark I modules.
(2) The positions of the green wire and the orange wire must be reversed where they are spliced into the four pin connector's wiring.
(3) The ballast resistor included with the wiring harness is not used for a Duraspark I application.
(4) The alignment lug on the Duraspark I coil tower must be removed to allow the Duraspark II horse shoe style coil connector to slide on. It helps to have a Dremel tool.
Its not the end of the world, these changes are easy to make. But I don't want you to have any surprises when your wiring harness arrives in the mail and you find the Duraspark I connector doesn't just slip into the harness connector.
Obviously it would be better to pull a harness from a 1977 - 1979 California car if you want to use the Duraspark I module, but that may be hard to do if you don't live in California.
Sorry I didn't think of this sooner, it's been a while since I've worked on a Ford with a Duraspark ignition.
I'm still searching for a wiring harness (quite a few bone yards in SoCal) to go with the system. But I need some suggestions on a coil to go with the DuraSpark system. I've heard some say MSD Blaster II that's is made for the DuraSpark system, Accel racing coil also that's made for the DuraSpark which is spring loaded and oil filled, a TFI coil (is the best per the Painless tech guy).
Are most coils going to pretty much give me the same thing (a heart attack if I get zapped no matter which one if I don't pay attention...LOL)? I'm not an electrical engineer but certainly have wasted plenty of time looking at how many micro seconds on spark duration, peak current, turns ratio, voltage, etc. From what I gather spark duration and lots of volts is better. Short of that my guess is their pretty much the same? Any suggestions?
I not going with the multi spark module.
Are most coils going to pretty much give me the same thing (a heart attack if I get zapped no matter which one if I don't pay attention...LOL)? I'm not an electrical engineer but certainly have wasted plenty of time looking at how many micro seconds on spark duration, peak current, turns ratio, voltage, etc. From what I gather spark duration and lots of volts is better. Short of that my guess is their pretty much the same? Any suggestions?
I not going with the multi spark module.
I think what will be most important is to match the primary resistance of the Duraspark I coil, which is lower than any other Ford coil. I have that info at home, I'll look it up for you this evening and post it here.
-G
-G
The Duraspark I coil had a primary resistance of 0.7 ohms, a secondary resistance of 7.3K to 8.2K ohms, and had no ballast resistor in the supply to the coil, the module controlled & optimized the charging of the coil primary by adjusting dwell.
The standard solid state module utilized the same coil as the breaker point ignitions with 1.17 ohms primary resistance and 7.7K to 9.3K ohms secondary resistance. It used the same ballast resistance as a breaker point ignition too (1.30 to 1.40 ohms in 1973 & 1974; 1.25 to 1.35 ohms in 1975 & 1976). In 1977 the ballast resistance of the standard solid state ignition was reduced to 1.05 to 1.15 ohms, and the coil and module were upgraded to handle the additional current and heat. The distributor cap was replaced with the larger cap to prevent crossfire, and the module was given the designation Duraspark II.
Duraspark I Coils: Motorcraft #DG-316 or Standard Motor Products #FD-477 (0.70Ω primary winding resistance). If you installed a 49 state Duraspark II coil in a Duraspark I ignition it will work, I've done it. The module will still do its best to optimize charging of the coil primary by adjusting dwell, and although its ultimate performance will be compromised it should still be as good or better than the the 49 state (Duraspark II) ignition. A possible source for the Duraspark I coil would be a NAPA store rather than a "speed shop". If you buy a NAPA coil I suggest taking your VOM with you to the store & measuring the coil primary resistance at the counter, since electrical parts are not returnable. I'd appreciate knowing what you end up buying and the part number.
Since I dug my ignition books out, I did a little reading, Ford solid state ignition was first used in 1973 Lincoln Mark IV (equipped with 460 V8s); in 1974 use of the solid state ignition was expanded to include all California emission controlled vehicles with 200 or more cubic inches, and all 49 state cars with 400 or 460 V8s. The solid state ignition was used fleet wide beginning 1975.
-G
The standard solid state module utilized the same coil as the breaker point ignitions with 1.17 ohms primary resistance and 7.7K to 9.3K ohms secondary resistance. It used the same ballast resistance as a breaker point ignition too (1.30 to 1.40 ohms in 1973 & 1974; 1.25 to 1.35 ohms in 1975 & 1976). In 1977 the ballast resistance of the standard solid state ignition was reduced to 1.05 to 1.15 ohms, and the coil and module were upgraded to handle the additional current and heat. The distributor cap was replaced with the larger cap to prevent crossfire, and the module was given the designation Duraspark II.
Duraspark I Coils: Motorcraft #DG-316 or Standard Motor Products #FD-477 (0.70Ω primary winding resistance). If you installed a 49 state Duraspark II coil in a Duraspark I ignition it will work, I've done it. The module will still do its best to optimize charging of the coil primary by adjusting dwell, and although its ultimate performance will be compromised it should still be as good or better than the the 49 state (Duraspark II) ignition. A possible source for the Duraspark I coil would be a NAPA store rather than a "speed shop". If you buy a NAPA coil I suggest taking your VOM with you to the store & measuring the coil primary resistance at the counter, since electrical parts are not returnable. I'd appreciate knowing what you end up buying and the part number.
Since I dug my ignition books out, I did a little reading, Ford solid state ignition was first used in 1973 Lincoln Mark IV (equipped with 460 V8s); in 1974 use of the solid state ignition was expanded to include all California emission controlled vehicles with 200 or more cubic inches, and all 49 state cars with 400 or 460 V8s. The solid state ignition was used fleet wide beginning 1975.
-G
Hey Tom,
I just removed a complete Duraspark system from my 351C. I should have everything you need. I have 2 control boxes,2 stock coils, A damaged distributor (case broken, don't ask) :-) and the wiring. Give me a call if you want some or all of it...
Take care, Scott
951-461-2190
I just removed a complete Duraspark system from my 351C. I should have everything you need. I have 2 control boxes,2 stock coils, A damaged distributor (case broken, don't ask) :-) and the wiring. Give me a call if you want some or all of it...
Take care, Scott
951-461-2190
quote:
Originally posted by George P:
Ford 1970's ignition modules ...
which amps should the fuse have on Duraspark II?
quote:
Originally posted by Anders Hellberg:
which amps should the fuse have on Duraspark II?
Ander's ... two comments
(1) I use a 20 amp fuse for Duraspark I. Duraspark II should draw less amperage, so a 20 amp fuse should be good for that application too.
(2) I cannot keep all of my posts up to date. So I focus my energy & attention on keeping Stick #3 up to date. For the best information on parts selection and other issues check out sticky #3.
-G
.