Ford DS II ignition upgrades?

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BobbyB
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Re: Ford DS II ignition upgrades?

Post by BobbyB »

travis wrote: Thu Mar 26, 2020 8:50 am I’m going to try just a coil upgrade first and see how that does, and go from there.

I do have a question about coils though. How do you determine what coils are compatible with your ignition system? Do you need to match the ohms of the stock coil semi-closely to an aftermarket coil. If you use one with considerably lower resistance, do you need to add a ballast resistor to get the total resistance closer to stock?
I used an Accell "SuperStock" oil filled coil on the 74 duraspark system. Everything worked great from 1990 until about a month ago when I upgraded to Pertronics Hei conversion as part of a new engine set up. By the way, I picked up an extra, made in USA 1974 (black grommet with 5 degree start retard) duraspart box from rock auto for less than $20.00... easy & cheap enough to keep a spare with you.
My427stang
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Re: Ford DS II ignition upgrades?

Post by My427stang »

Absolutely nothing wrong with a Duraspark 2 distributor, as stated earlier, the mag pickup is the same as some aftermarket distributors. A little more funky to work advance limits, but once you have it dialed in, the advance works real nice and smooth, better than the GM/MSD swinging sickles, which are super convenient but can be a little choppy

Where it gets a little more difficult:
1. Small cap can get funky with big cylinder pressures, high RPM and crossfire, but easily fixed with a big cap.
2. Good Duraspark ignition boxes are harder to find. The originals didn't only have a second circuit fed by 12V, that circuit also had a start retard, which could be convenient. As I understand, the cheap boxes don't have that, and actually tie the red and white wire together and just feed the same circuit.
3. No rev limiter, but the last point and this one are easily fixed by using an aftermarket CD box with a Duraspark distributor, once curved it's a super reliable piece.

What really stinks:
- The weird wire plugs design Ford used, sure it's sealed well and if not taken apart will last forever, but try to get an old one apart, they almost always get brittle and break. That being said, lots of options to fix those easily if you don't need "concours correct"
Bullock's Power Service, LLC
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70 Mustang, 489 FE, TKO-600, Massflo SEFI, 4.11s
71 F100 SB 4x4, 461 FE, 4 speed, port injected EFI, 3.50s
Paul Kane
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Re: Ford DS II ignition upgrades?

Post by Paul Kane »

Paul Kane wrote: Wed Mar 25, 2020 8:36 pmMSD’s reluctor and magnetic pickup coil are, in fact, the same FoMoCo reluctor and pickup coil as in your factory Dura-Spark distributor. This is probably why MSD offers instructions to wire a Dura-Spark box to their MSD model distributor and/or an MSD box to a Dura-Spark dizzy.
A bit more info regarding MSD's association with the Ford ignition systems:

Ford SVO used to offer a performance Duraspark ignition module which was made by MSD and would even accept the MSD rev limiter chips. I don't know exactly what the internals consisted of but I believe it was some kind of an MSD 6AL or thereabouts. Known FoMoCo part numbers for the private labeled MSD DuraSpark module are:

  • M-12199-C301
  • M-12199-A351
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My427stang
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Re: Ford DS II ignition upgrades?

Post by My427stang »

I'd like one of those on my old Ford pickup...

MSD also made a Ford branded 6A box, identical to the red 6A we all know, but blue instead of red and labelled Ford Racing. I tried to find a picture of one but couldn't, but I see one at this particular swap meet every year for 10 bucks from the same guy. Labelled "works" in masking tape but nobody ever buys it, if it's there this year I may buy it just for the long memory of seeing it each year :)
Bullock's Power Service, LLC
Plattsmouth, NE
70 Mustang, 489 FE, TKO-600, Massflo SEFI, 4.11s
71 F100 SB 4x4, 461 FE, 4 speed, port injected EFI, 3.50s
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