351w Duraspark questions - Ford Truck Enthusiasts Forums

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351w Duraspark questions

 
  #1  
Old 03-07-2019, 07:22 PM
SixerFixer
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351w Duraspark questions


The diagram seems pretty straight forward one problem is that I don't have a resistive load before the coil as the 1996 F150 this 70's Windsor is going into never had one of these in the factory harness. The ignition module is a rock auto special, the dizzy is a factory Motorcraft with an MSD red top. Is it ok to use it with no resistor in place? I don't think it would be ok, but im new to these things and there's always something new to learn even if you didn't mean too. So just to make sure i've got my T's dotted and my I's crossed, the three wires coming off the dizzy connect to ignition module while the fourth wire off the box goes to one post on the coil(Tach), the white wire and red wire im a little fuzzy on; the red and white wires appear to be one resistive wire for driving to limit current draw on the coil to lessen the burden on the alternator while driving, and one non resisted to let current free flow for starting purposes. What i'm fuzzy on is how i get two from one. I've only got one red non-resistive coil wire and one yellow tach wire(does the tach wire go on the same pole on the coil as the green module wire or is that connected somewhere else....?) The swap was a 300 six with a four barrel to a 351w with a four barrel. The 300 wasn't maintained by P.O. and died after a long battle with heads, coolant and oil. The Mazda five speed will be kept in place, upgraded to an 11" clutch. The Mazda should live a reasonably long life behind the Windsor as the truck has 2:73 gears and will only be a DD with occasional towing no more than 6k lbs. Any and all help is much appreciated.
 
  #2  
Old 03-07-2019, 08:35 PM
whisler
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To convert my '89 to a 351W with Duraspark ignition I did this: Found the wire that originally fed the ignition system (mine was white/blue) Should be hot in "run" and "start" only. I used a Chrysler resistor (about 1.3 ohms), NAPA Echlin ICR11 is one option. There are others in the same ohm range. You need the resistor to keep from burning up the coil.
Mount the resistor where it will get good air flow but not get wet. Ran the white/ blue (or whatever color your wire is) to one side of the resistor.
Ran a wire from the same side of the resistor to the red wire of the ign. module.
Ran a wire from the other side of the resistor to the (+) side of a Duraspark coil. Don't use the EFI coil.
I used the older style starter solenoid with both the S and I small terminals. you need both terminals.
Ran a wire from S terminal to the white wire of the ign. module. Then ran a wire from the I terminal to the coil +.
Instructions were courtesy of Franklin2 on the 80-86 section of the forum and they worked fine.
 
  #3  
Old 03-08-2019, 07:49 PM
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Dude paragraphs please.... Anyway use a Chrysler resistor as mentioned (about 1.1 ohm and high wattage) Find at auto parts store for 1967-1980 mopars.

You'd be better off running your original square coil with a Red grommet duraspark #LX210--No resistor needed and you get much hotter HEI spark!

Starter solenoid has several terminals, white gets power only when starting, another wire red, gets 12v when running, and the positive terminal of coil will get 12v when starting ONLY and then like 9V from the resistor when running.

If you can't figure this one out just buy the Red duraspark and forget about the resistor and use your square coil. Prob solved.
 
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Old 03-14-2019, 11:33 PM
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My apologies on my tardiness to respond just been busy with finding perches, welding exhaust, engine swapping..etc Just the usual shenanigans but the engine is bolted up the the tranny, just not to the frame yet. I need v8 perches which a local(30 miles away) u pick it just so happens to have.

Ignition wise, i finally got the ignition module and am routing wires and making drawings so I know(and whoever gets the truck if i ever sell it) where all the wires go and their purpose. I finally have a handle on the routing for the ignition wiring and will be in the process of making it a reality within the next few days along with other various things to get the truck finished and on the road. Finding info on the specifics of a 351w and m5r2 together was akin to that of hens teeth. Nobody who did it gave anything helpful other than " It went together but it probably wont last long."

Well I went ahead and charged on into the known but unshared.... and it went together without a hitch. Pilot bearing and everything was the same sizes. The ford 300 flywheel was strange as I was told they were only drilled for 1. 10" clutch, 2. 11" clutch 3. 10" and 11" clutches. But mine had 10", 10.5", and 11" patterns..... I had a stage 2 10.5" clutch kit for a 302 that went on like it was made for it. weird......(Though it may sound like I used the 300 flywheel on the windsor, I didn't as i'm well aware of the differences in balancing between the 2 engines.) Anyways, more to come.
 
 


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