Duraspark ignition upgrade/swap

[bluebronco69]

Looking for a good full write-up or how-to for a duraspark swap. Looking to do this in my dad's 72. What can we grab from the junkyard? What should we get new?

 

[broncnaz]

You can grab everything from the junkyard dizzy with cap, coil, wiring and module. The dizzy needs t be off a 302 if thats what your swapping it onto. You'll want to look at 76 up cars or trucks. For the module coil and wiring you can get it off any vehicle any engine just look for one with the blue gromment where the wires come out. Id try to get stuff out of a vehicle that may have been in a wreck or looked like it was running recently. Should be some writeups on the internet but other than a wiring diagram it pretty straight forward. This is the basic wiring diagram
Sometimes it may be better just to grab a junkyard dizzy as a core then get a remanned one at the parts store they are usually around $50

 

[savage]

I just did mine, but I used new parts, and made my harness. If you can find a used one like broncnaz suggested it might be easier. Here's the thread on the one I made out of new parts.http://classicbroncos.com/forums/showthread.php?t=258904

 

[ntsqd]

Look for an original Motorcraft module and don't be put off by finding one that is nasty looking but will clean up fine.

On the module plug with the white & red wires, I always try to cut those wires as long as I possibly can. Might save needing to extend them.

Research the correct starter solenoid to use. I have had some hang closed with the white wire connected. Some vehicles will start without the white wire connected to anything, others will not. Those that do start w/o it actually fire when you release the key from cranking mode.

 

[bteutsch]

Got my harness from a junkyard late 70's f100 that had Duraspark module with the blue relief. Got the dizzy from Napa. Reused my small cap and rotor. Got a motorcraft module from ABC auto parts. Just reused my old coil.
Used a diagram I got off of a Duraspark thread on here posted by viperwolf

Sent from my iPhone using Tapatalk

 

[bluebronco69]

So do you need an entire replacement distributor or can I use the original (and swap the guts), and just add on the duraspark box to eliminate the points

 

[jckkys]

A good source of US made Motorcraft modules is ebey, by searching Motorcraft DY-683. These were the last application of Duraspark II modules; F700s with 429s through '98. Part stores only carry Chinese junk. Every Duraspark failure I've seen is either a pre 1980 part or aftermarket. My '84 module is flawless through 30+ yrs. The Painless Duraspark harness is good quality but wildly over priced. A junk yard take off pays on this part, unless you make your own.

 

[jckkys]

It would be worth a couple bucks to get a Duraspark distributor. The lower shaft of the points distributor is better than the Duraspark because it has larger stiffer centrifugal weight pivots. So you may want to keep that.

 

[ntsqd]

So do you need an entire replacement distributor or can I use the original (and swap the guts), and just add on the duraspark box to eliminate the points

To convert a points dist to D-S II you'll need the reluctor, it's retaining roll pin, the pick-up assembly, the plate it rotates on, and the upper shaft of the dist. Note that there are numbers stamped in the plate on the bottom of the upper shaft adjacent to the slots on the ends and that they are different. Those are the mechanical advance possible in that slot. Ideally you'll find one that has a number close to the current advance limiter and you can use it to duplicate your existing mech. advance. You may also need the vacuum advance unit. I've had some not fit right with no idea why, as I understand it they should be the same. You'll also have to turn the points wire hole in the dist body into a slot.

 

[SHX669]

If you decide to go with new stuff Davis Unified Ignition {DUI} sells an upgraded DurasparkII dizzy and Control Module.

 

[toddz69]

And sadly, good luck finding this stuff in the junkyards anymore. It's just not common at all anymore.

Todd Z.

 

[ntsqd]

Anyone bought one of the Davis modules? Last time I looked at their page the picture for the D-S II module was a Mopar module.

 

[jckkys]

The real Duraspark modules have features not found on Mopar or GM HEI ignitions. Coil saturation and cranking retard are part of the Duraspark II only. The Davis distributor is simply a rebuild, no upgrades. Read this write up on Durasparks; http://www.ifsja.org/forums/vb/showthread.php?t=19440 or this one; http://www.fordmuscleforums.com/all...spark-ii-ignition-retard-fallacy-fiction.html. Just get good quality Motorcraft module and rebuild a 302 Duraspark distributor. The common parts from both the Duraspark and point units allow you to select the best ones. If a good wiring harness can't be found in used condition, the Painless version is of better quality than OE, even if costly.

 

[RedLeg0811]

302 or 351W? If 351w I just pulled my dura spark setup with a crane adjustable vacuum. I rebuilt a Unilite I had with pertronix guts. It was also easier for me to disable all timing for my Go EFI.

Anyway I was going to put the dura sparc up for sale.

 

[ntsqd]

I don't believe that first link, it itself has of errors (the first of which is being a Jeep page!). One error example is that the HEI system is NOT triggered by Hall Effect as stated in that page. TFI's are triggered by Hall Effect, but HEI's (& D-S II's, & MOPAR EI boxes, & MSD's/Cranes/Stingers/etc.) are triggered inductively. If the author can't get that simple thing right, what else did he screw up?

 

[broncnaz]

So do you need an entire replacement distributor or can I use the original (and swap the guts), and just add on the duraspark box to eliminate the points

As was said you can swap the stuff around but really why? Its more work than its worth unless you just had a duraspark setup out of a different engine sitting around. For the most part the pickup on the duraspark is the only part that really goes bad. If you get a used setup inspect the wires going to the pickup closely as they tend to crack where they enter the pickup.
For the cost Id just get a remaned one from the parts store and be done. If your donor dizzy is not in that great of shape.

 

[ntsqd]

If you have a re-curved points dist. or the budget is tiny I'd swap the parts paying particular attention to the mech. advance limit slot being the same.

If it's just any old points dist. I'd buy a new one.

 

[jckkys]

Unfortunately the upper shaft or sleeve and plate assembly, that is is either point style or Duraspark isn't interchangeable. So the limiting slot that's a big factor in any advance curve is also either point type or Duraspark, not both. The best part has a 10L advance limiting slot. Read this;http://vb.foureyedpride.com/showthread.php?22229-The-Ultimate-Duraspark-Distributor-Timing-Guide.

 

[ntsqd]

I have built D-S II dist.'s from a points dist. donor, so I'm not sure what you mean by "not interchangeable". They do have to be swapped as a set, you can't mix and match points parts with D-S II parts if that's what you're saying. If it is to be a D-S II dist. it needs to have the D-S II pick-up base plate, the D-S II pick-up assembly, the D-S II upper shaft, the D-S II reluctor, and the D-S II reluctor roll pin. No points parts can replace any of those pieces. Are we saying the same thing?

 

[jckkys]

The upper shaft has a cam, on points type. The Duraspark upper shaft, has a key-way to time the armature. They are completely different. The case, the biggest part, has a round hole for single wire, on the points distributor and a notch for the 3 wire harness, on the Duraspark. The reluctor plate, that has the advance limiting notches plate, is welded to the upper shaft or sleeve. You can't buy these parts separately, only as whole distributors.