This 4 now frm my archive…back w/something better later.
DSII & HEI
The best of all worlds ! The dura spark is one of the strongest magnetic pickup coils on the market and is very reliable! Couple this with the GM HEI control module and you have the system ! The GM HEI uses a .5 ohm ignition coil and controls primary current at a peak 5.5 amps. A dwell control with low dwell at low rpm and increased dwell with additional rpm has made this one of the better control modules on the market as well.
Wiring is pretty straightforward :
DISTRIBUTOR HAS THREE LEADS:
1-Black lead goes to good engine ground.
2-Red/black lead goes to white lead on module ( terminal G small terminal)
3-Purple /black lead goes to black lead on module (terminalW )
Control Module ( must have good system ground!!!) Is 4 pin…
Terminal:
W= pickup coil in distributor (purple lead)
G= pickup coil in distributor (orange or red lead)
C= coil negative terminal
B= coil battery terminal
Terminal B is then hooked to key on off to run……
Hope this helps, sent a text to you. Bill
http://www.bronco.vandervortsweb.com/node/25
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HomebrewHEI
Making your own HEI Distributor for a Ford
Using An HEI Module With A Duraspark Distributor
A lot of guys update their ignition to the Duraspark II system. This requires pulling out the stock distributor and coil and replacing them with the Duraspark distributor, coil, module, starter solenoid, and ballast resistor. Yeah its complicated and can get spendy but what else is there besides an even spendier aftermarket system? Well, if you don't mind a little cross breeding you can use a GM HEI ignition module. All that's required is a Duraspark distributor, HEI module, and coil. Because of the dwell control and current limiting circuits of the HEI you can use just about any coil you want, and no ballast resistor is needed.
All you will need to buy is a Duraspark distributor, HEI module, and some wire and connectors to hook it all up. The cheapest place to get the Duraspark distributor is at a junkyard or swap meet, usually $20 or less. Duraspark distributors came on Ford cars and trucks from the mid seventies through the mid eighties. You could also get a rebuilt one at the auto parts store, generally $40 or more. Be sure you get one for the same model engine you have 302 or 351W, many of them look very similar but are not interchangeable. On some engines, like the 302, you need to match the gear material to the camshaft you are using. Flat tappet cams use a cast gear where roller cams use a steel gear. If you look at the shank above the teeth a cast gear will be a rough cast finish where a steel gear will be a smooth machined finish. If you want a small block distributor with a cast gear tell the parts guy you want one for a 5-speed '84 Mustang GT. For a steel gear tell him you have a 5-speed '85 Mustang GT. If the guy at the parts store has two distributors listed and doesn't know which is which, the one with the cast gear is always considerably cheaper than the one with the steel gear.
For the module you want a GM 4-pin HEI. They came on GM vehicles from the mid seventies through the early eighties. You can buy one new at any auto parts store. Any good parts guy will know exactly what a four-pin HEI module is. Although good parts guys are hard to find so you will probably need to ask for an ignition module for a '78 Camaro with a 350. Since they are so cheap you don't need to go to the junkyard. Besides, all the junkyards around here wouldn't even sell me just the module, they wanted me to buy the whole HEI distributor to get it. The module in the picture is a Car Quest #21040 and cost me $17.77. As you can see there are four pins labeled W, G, B, and C. The G pin is a 3/16" (0.187") male quick disconnect and the rest are 1/4" (0.250") male quick disconnects. I recommend you stay away from the Parts Master module #LX-301. All the failures I have seen and heard about were due to the Parts Master module.
The HEI module gets pretty hot, whatever it's mounted to needs to act as a heat sink and carry heat away from it. Mount it securely to a flat metal surface away from the headers or other heat sources. There are two pins on the back of the module that you need to break off so it will sit flat. The module will come with some heat sink compound, smear it evenly over the back of the module before bolting it down. The compound aids heat transfer. You could also mount the module to a big heat sink. I bolted mine to a heat sink from a slot type computer processor. If you're a computer geek like myself then you probably have one laying around. If not then you can buy one at Radio Shack or a computer store. Again you will want to use the heat sink compound between the module and heat sink.
NEW! THE GM HEI IS A POWER HOG!! Use a Continuous Hold Solenoid or a 15 amp relay and 10 AWG wire to supply the module's current demands!
Once you have it mounted you need to wire it up. The B pin goes to the positive coil lead which gets power when the key is on, and C goes to the negative coil lead. The tach .also hooks to the negative coil lead. If you are converting from fuel injection then the coil is already wired for power (red) and tach .(green). Splice into these wires. Don't remove them from the coil just add some wires to them and run them to the module. On an older car you will need to bypass the ballast resistor so you get full power to the coil and module. The Duraspark distributor has a funky three pin connector. You can just plug into it with standard 3/16" female quick disconnects. The purple wire is run to the G pin on the module, and the orange wire is run to the W pin. Run the black wire to one of the mounting screws on the module. The black wire provides a solid ground connection for the module. The module must be grounded or it will not work properly.
Like I said before you can use just about any coil you want.
Basically the only coils that you can't use are aftermarket coils which are for CD (capacitive discharge) ignitions only. I recommend the TFI coil, its the square looking coil used on fuel injected Fords. They are dirt cheap and work great because they were designed for the Ford TFI which is basically the same thing as the GM HEI. If the TFI and HEI modules are the same then why can't I use the TFI? The TFI distributor uses a Hall sensor instead of a magnetic pickup so the TFI module will not recognize the "analog" signal from a Duraspark distributor. However, you could hook a TFI module to breaker points since they put out a "digital" signal like the Hall sensor. No matter what coil you use you will not need a ballast resistor. The purpose of a ballast resistor is to add series resistance to limit current through the coil. The HEI actually measure the current and when it reaches a certain point resistance is added using the switching transistor to prevent excessive current draw. So basically it has a built-in self adjusting ballast resistor.
That's all there is to it. Its easy, cheap, and a great performer. You could spend five times more on an ignition and chances are you won't see much, if any, improvement.
Another Picture
Parts Ref
GM 4-pin HEI
• Car Quest #21040
• Parts Master module #LX-301 (Possibly lower quality)
• Wells DR100
• Standard LX301 (~$28)
• Napa: Echlin ECHTP45 (~$38.49)
• Niehoff DR400
• AC DELCO D1906 (~$33)
Trouble Shooting
Module:
• W = positive lead (+) from the pickup
• G = negative lead (-) from the pickup
• C = negative side (-) of the coil
• B = positive side (+) of the coil
• Grd = ground terminal, and it is one of the holes that the screw runs through to attach the module.
C B G W
__ __ __ __
\_\_ \_\ /_/__/_/
\ \___________/ /
\ /
\ (Grd) ( ) /
\___________________/
1. Remove the module. (watch out for the dielectric grease on the underside, It's relatively harmless, but goopy
2. Connect a test lamp between the B and C module terminals and jumper +12 volts to the B terminal and then ground the module at the (Grd) terminal. If the lamp lights then the module is bad.
3. If the module passes step one, then jumper between the B and G terminals. If the lamp lights, the module is probably OK.
Pros / Cons
• HEI Conversion System
◦ Doesn't require ballast resistor
◦ Can be triggered by any variable reluctor type distributor such as the duraspark distributor, but NOT Opto-Electronic (Mallory Unilite) or Hall Effect type distributors.
◦ Decent spark output, about the same as a duraspark module.
◦ Cheap, available module ($20-$30).
•
• Duraspark System
◦ Stock on many Broncos
◦ Good, accurate, reliable spark.
◦ Timing retard while starting (Especially good for colder climates / Mountains). This also lets you run additional initial advance.
Definitions
VR (Variable Reluctor) Sensor
Consists of a star-like mechanism that rotates and a coil where the points used to be. When the star aligns with the coil in the sensor, the reluctance of the magnetic path is radically changed and that induces a pulse in the pickup coil. The VR sensor is an induction type sensor, it is passive;, i.e. it does not require a power source, and has a small magnet built in. It basically works like a dynamo. The output of this sensor varies with the speed of the engine. At idle the output is approximately .6 volts, at mid RPM it is closer to 3 volts, and at high revs it goes to almost 50 volts. You have to keep in mind that this type of sensor produces an AC output. The pulse is positive when the pole is approaching, and negative when the pole is leaving (provided you have the right polarity). The simplest way to see this is by hooking it up to a cheap analog voltmeter and using a wrench or other non magnetic - soft iron; piece of metal. When you put the metal piece on the sensor the needle on the voltmeter will swing one way. When you quickly remove it the needle will swing the other way.
Hall Effect Sensor
A Hall sensor is an active magnetic field presence sensor. It is based on the Hall effect, that is a semiconductor changes its resistance in a presence of a magnetic field. These types of sensors require a flying magnet wheel. Instead of teeth on the wheel you must have small magnets. This type of sensor has an electronic circuitry built inside and thus provides a constant voltage pulse regardless of the speed. The sensor is also sensitive to the polarity of the magnet. N pole will turn it on, S will not, or vice versa dependent on the orientation of the sensor. The pulse produced is as long as there is a magnetic field of some strength present, and is always of the same polarity (positive with respect to ground).
I better stop, this is too much stuff to put on the site. I have a great schematic from 'gofast'. That's what I should send U...
