HEI distributor on 351W

[Andre]

I read a lot about the HEI on the straight 6, but not that much on the V8. I was thinking about it, mainly because I like a clean engine bay. Does the HEI system gives any other advantages over the one wire and no need for ignition coil? Its known for clearance issue's in regards to the intake manifold, but I think that will clear with the Edelbrock manifold I have. Also my intake filter has a 1 inch off center hole, so that should all clear the big HEI distributor cap.
At the moment I have the MSD ready to run distributor, and all is performing well. Did find out that after start the voltage drops to around 8 volts, due to the resistance wire at the dash to the plus of the ignition coil, the MSD distributor can cope with that, I dont think the HEI will, and requires a straight 12 volt supply.
Any information would be great, and if possible the do or dont's of the HEI system on the Ford V8.

[ArdWrknTrk]

The 'coil in cap' GM style distributors need a hefty 10-12Ga. wire directly from the battery cable lug to supply enough power.

You use the coil power wire to trigger a relay, and supply the HEI.
Not surprisingly Gary has a write-up under "upgrades"

[Gary Lewis]

Jim - There may be one under "upgrades", but the one I refer people to is on the page at Documentation/Electrical/Ignition and then the Ignition Simplification and One Wire tabs.  There are some advantages and disadvantages there also.

Andre - I saw what you said about the notch in the air cleaner.  But I'm not sure that an HEI will fit under there.

[Andre]

Thanks guys, I think I wont be change it until its broken, maybe order one for the Ranchero, just to make sure it fits the Bronco too. Ranchero has a lot of electrics to be done, as its not there anymore.

[Rusty_S85]

Id make sure on the HEI if you go that route on a 351W.  We had a 351W stroker in a 92 F150 at work that we put that distributor in and it had a lot of slop when we were trying to find out why it wiped out the distributor gear.  Could have been just his block but could have been the HEI distributor as well.

Personally I wouldnt go to the trouble of doing that upgrade as I dont believe it is an upgrade as GM ignition modules fail due to heat over time and Ive personally never had a DSII Ignition module fail as it is mounted away from the engine on the fender.

But the HEI does have its benefits though such as having a tach clip you can use or leave empty and all you need is just a battery hot for the distributor.  But aside from that I dont know if for me the benefits of the HEI style distributor would out weigh the negatives in my book.

If I make any changes to mine I would consider going with one of the holley hyperspark distributors to allow my Sniper Stealth to control ignition timing.  But even then they have RFI problems and apparently you can use a factory style distributor you just have to lock the advance but I never really looked into that as I am not too big on letting the EFI control my timing.

[Nothing Special]

I have a GM HEI distributor from Davis Unified Ignition (DUI, cute huh?) in the 302 in my '71 Bronco.  No one told me that I can't run it directly off the wire from the ignition switch.  But apparently no one told it either as it's been working well that way for over 10 years (sometime maybe I'll put a relay on it...).

I went with an HEI to replace the original '71 breaker point system.  No regrets on my choice, but I'm not saying it's the right choice for everyone.

I have heard that there are several different vendors offering HEI distributors of varying quality at varying price.  DUI is DEFINITELY not the cheapest, but I guess they're good.

The only issue at all that I've had wasn't actually with the distributor, but with the plug wires I ordered from DUI at the same time.  They came for the wrong firing order so they were the wrong lengths.  This far after the fact I don't recall how the error was made, but I returned them and they sent me the right ones, so no big deal fixing it.

[ArdWrknTrk]

Bob, I know I'm NOT about to pay $400 for any distributor.

But if you look at the instructions on Performance Distributors DUI page you'll see that while they say to run a 12Ga. wire directly from the ignition switch on GM vehicles they suggest a relay for Ford.
The other "HEI" brands seem to suggest using a relay on installs too.

I don't know if/how a '70's Ford harness differs from these trucks.

If it works for you, it's all good!  

[85lebaront2]

Rusty, FWIW, British cars, MG, Jaguar etc. used a Lucas Opus (Oscillating Pickup system) that the pickup was a small transformer with an incomplete frame, one of the sides was omitted. The transformer frame was completed when the ferrite rod in a plastic spool on the distributor shaft aligned with the pickup. It was, in the best tradition of Joe Lucas questionable at best. In 1980 while I was working at a Dodge, Jaguar, MG and Mercedes-Benz dealer, a replacement was released by Lucas called a "constant energy ignition" it used what looked like an old Chrysler electronic ignition pickup and reluctor 4 or 5 teeth as needed. The aluminum box with the Lucas label had two connectors 90° apart one set was connected to the pickup coil, the other went to the ignition coil + and -. Instructions were to remove the coil and remount it in place with the ballast resistor removed and the new ignition box under it, replace the existing distributor with the Opus module with a new distributor containing the pickup. Pickup air gap was set like a Chrysler at .006" with a non-magnetic feeler gauge.

I opened one of the boxes, inside it was a GM 4 pin HEI module. Apparently it is the GM coil that is the power hog, not the module. I would imagine if you used a DS-II distributor and an E-core coil that a properly mounted to a heat sink 4 pin HEI module would work very happily and possibly a DS-II coil might also, but the module would need a 12V feed rather than the resistor feed. The DS-II coil might work without the resistance wire. This would allow a normal DS-II distributor and wires to be used and the module could be put in a failed DS-II case.

[Nothing Special]

ArdWrknTrk wrote

Bob, I know I'm NOT about to pay $400 for any distributor.

Like I said, DEFINITELY not the cheapest!  And honestly, I don't recall my thought process (or lack thereof) that led to the purchase way back when.  But the nice thing is that now I've basically forgotten the price I paid and only remember that it works well.

ArdWrknTrk wrote

But if you look at the instructions on Performance Distributors DUI page you'll see that while they say to run a 12Ga. wire directly from the ignition switch on GM vehicles they suggest a relay for Ford....

I don't know if they didn't say that back when I bought mine, or if I just missed it.  But...

ArdWrknTrk wrote

If it works for you, it's all good!  

... that's what I'm going with!

[ArdWrknTrk]

Bill, why not use the 5-pin module from the Toranado and get spark retard on cranking as well? (If wired to 'I')

I know some guys who used forced induction or juice use these modules to good effect.

[85lebaront2]

Jim, I didn't know the Toronado had a retard in the distributor. I know the first round of CCC engines had a fixed advance distributor and the computer controlled the spark advance, I believe they were a 6 pin module  though.

[ArdWrknTrk]

Well, with as much advance as most Ford engines use anything to the starter's labor is a good thing.

That's why it's built in to DSII, and would probably be a good feature if using an HEI.

And yet, even though DUI is 'optimized for your application' they can't be bothered to use the module with it (that doesn't cost a penny more) or give you the three feet of wire.

Even though they are probably the most expensive ignition widely available.

[Rusty_S85]

85lebaront2 wrote

Rusty, FWIW, British cars, MG, Jaguar etc. used a Lucas Opus (Oscillating Pickup system) that the pickup was a small transformer with an incomplete frame, one of the sides was omitted. The transformer frame was completed when the ferrite rod in a plastic spool on the distributor shaft aligned with the pickup. It was, in the best tradition of Joe Lucas questionable at best. In 1980 while I was working at a Dodge, Jaguar, MG and Mercedes-Benz dealer, a replacement was released by Lucas called a "constant energy ignition" it used what looked like an old Chrysler electronic ignition pickup and reluctor 4 or 5 teeth as needed. The aluminum box with the Lucas label had two connectors 90° apart one set was connected to the pickup coil, the other went to the ignition coil + and -. Instructions were to remove the coil and remount it in place with the ballast resistor removed and the new ignition box under it, replace the existing distributor with the Opus module with a new distributor containing the pickup. Pickup air gap was set like a Chrysler at .006" with a non-magnetic feeler gauge.

I opened one of the boxes, inside it was a GM 4 pin HEI module. Apparently it is the GM coil that is the power hog, not the module. I would imagine if you used a DS-II distributor and an E-core coil that a properly mounted to a heat sink 4 pin HEI module would work very happily and possibly a DS-II coil might also, but the module would need a 12V feed rather than the resistor feed. The DS-II coil might work without the resistance wire. This would allow a normal DS-II distributor and wires to be used and the module could be put in a failed DS-II case.

The coil is a power hog, I didnt mean to imply the module was a power hog, its just the module being inside the distributor has no way to be cooled by air and thus requires the thermal paste to transfer heat to the distributor housing to try and keep the module from overheating.  The electrical load may not be high but it does build up when you introduce engine heat as well.  I got like 15 GM modules at work for HEI that are new that I keep on hand for swaping into HEI no start conditions cause I see them fail so often.  Its why when we do a HEI distributor in a GM car we toss the generic module that comes with it and install a brand new AC Delco module as they tend to be a bit more durable.

In theory you could convert any distributor, I converted my points Holly LoadOMatic distributor to electronic with Petronix, its basically like Ford or GM HEI using magnetics to trigger the coil and they include a clear acrylic piece of plastic to set your air gap for proper operation.

For me I will stick with my Ford HEI which is what DSII is it just doesnt integrate the coil and module into the distributor like GM did.  Im really curious how ever if one could use the DSII ignition module and distributor and lock the advance out and use a tach drive to control the DSII module/coil.  I never thought of that but if it could be done that would be the best of both worlds for me as I could simply splice into my new distributor wiring for the sniper to trigger my DSII module and I can retain OE module and Coil but use my sniper for controlling my timing.  Would be better than going with the holley supplied distributor unit which I keep reading horror stories over introducing RFI into the system.

[85lebaront2]

Rusty, if you look at a DS-III module, it was the one the EEC-III systems used and the computer controls the timing, possibly that would work with your Sniper system. If I can figure out a way, I just looked up and saved the ignition system for the EEC-III the other day for a fellow in the Bullnose group on FB, he has a CA spec 1983 351 truck and wants to properly delete the EEC-III crap.

The orange wire on the EEC-III module is connected to the computer, now we just need to find out if it uses a + or - signal to trigger. No signal = no advance, locked at static, but, these systems used a crank trigger.

[Rusty_S85]

Sounds interesting I might need to look into that as an option.  I do like the idea of having computer controlled timing via the sniper, will make timing curves a breeze to tune.  I just never looked into it because I know that the distributor from holley is recommended and 9 out of 10 people have RFI problems when they made that upgrade that were not there before hand.

The DSIII module does it use the same plugs as the DSII making it a plug and play swap?  Or did they change the connectors to prevent fools from accidently attaching a DSII or DSIII module to the wrong system?

[85lebaront2]

Rusty, my AllData does not tell me that, maybe looking at Rock Auto's pictures of aftermarket modules might help, or someone on here who has done an EEC-III removal. Gary may even have something as the cab he is using on "Dad's truck" was from an EEC-III model.

[85lebaront2]

Ok, Rusty, I did some research. The DS-II module has a total of 6 wires, three to the distributor for pickup signal and ground, one to the coil negative all of which are in one connector, C323 with 4 pins. The other connector C321, is a two pin and the red and white wires for ignition power and start signal are in it.

On the DS-III there are only 5 wires, and one goes to the EEC, one to coil negative and one to ground, these are in C105. The power and start are the same in C321.

Here is a picture of the Excel spreadsheet: