Hello All - 1986 F150, 2wd, base trim, 300 engine, 4 speed

[shosh86]

I'm interested in how the hei works. I know how they work. I have used them a few times on 5.0 engines.

I don't use them on restorations for obvious reasons. my 86 4.9 has all stock system. same as yours except it's a c6 auto. it has been my daily driver since 1991. bubba is "ole reliable" and for that reason alone it is still all stock. I have no complaints! feedback, thickfilm dist, etc.

What's the reason you don't use HEIs on restorations?

[mat in tn]

What's the reason you don't use HEIs on restorations?

ford did not offer them

[ArdWrknTrk]

What's the reason you don't use HEIs on restorations?

I think the biggest reason is that if it fails you have to order a new one from Timbuktu.

Where as most local auto parts have a DS-iI module or distributor (or can get one that day)

I've got nothing against an HEI as an 'all-in-one' solution for converting or eliminating EEC-III/IV as long as you understand that it won't run right on the stock coil power and you must wire it up with a relay + minimum 12Ga fused power in start and run.

[Gary Lewis]

I think the biggest reason is that if it fails you have to order a new one from Timbuktu.

Where as most local auto parts have a DS-iI module or distributor (or can get one that day)

I've got nothing against an HEI as an 'all-in-one' solution for converting or eliminating EEC-III/IV as long as you understand that it won't run right on the stock coil power and you must wire it up with a relay + minimum 12Ga fused power in start and run.

Right, and right.

High Energy Ignition, HEI, was designed by GM and used on their vehicles from '75 until computers took over that task. And even then there were HEI systems that had computer connections.

And right that they are power hungry and require at least a 12 gauge wire from the battery to the ignition. But you can't find that much power controlled by the ignition switch under the hood of a Ford vehicle so you have to install a relay.

It isn't so much the wattage that is used in the ignition as it is the massive inrush current that is used to charge the coil. So while overall it would look like smaller wire would be fine, you need the larger wire to handle the short burst of high current as the ignition is preparing to fire the next plug.

[Gary Lewis]

Right, and right.

High Energy Ignition, HEI, was designed by GM and used on their vehicles from '75 until computers took over that task. And even then there were HEI systems that had computer connections.

And right that they are power hungry and require at least a 12 gauge wire from the battery to the ignition. But you can't find that much power controlled by the ignition switch under the hood of a Ford vehicle so you have to install a relay.

It isn't so much the wattage that is used in the ignition as it is the massive inrush current that is used to charge the coil. So while overall it would look like smaller wire would be fine, you need the larger wire to handle the short burst of high current as the ignition is preparing to fire the next plug.

I remembered that there is a writeup regarding this on the page at Documentation/Electrical/Ignition and then the Ignition Simplification and the One-Wire tabs. In part it says:

The power to a one-wire needs to be substantial since they require a lot of current, and should be at least a #12 wire. You can get that power from Circuit 37, which is a large yellow wire that is usually dead-ended below the brake master cylinder. If you have a factory auxiliary battery you'll have a relay on the firewall to the right of the master cylinder, and Circuit 37 will be connected to it, as shown below. Or, if you have the trailering option or a DRW truck you may have a power stud on the firewall with Circuit #37 connected to it. In any case you can connect to that circuit to get battery power for the ignition. However, you should put a fuse, probably a 20a one, in the circuit as that wire uses a fusible link that is capable of far more current than you need for the one-wire distributor.

So if you have that circuit, and you should, then you can connect to it for your HEI. But as that wire is hot at all times you still need the relay. And I'd still fuse it.

You can see a suggested wiring diagram for the relay on that page.

[ArdWrknTrk]

I remembered that there is a writeup regarding this on the page at Documentation/Electrical/Ignition and then the Ignition Simplification and the One-Wire tabs. In part it says:

The power to a one-wire needs to be substantial since they require a lot of current, and should be at least a #12 wire. You can get that power from Circuit 37, which is a large yellow wire that is usually dead-ended below the brake master cylinder. If you have a factory auxiliary battery you'll have a relay on the firewall to the right of the master cylinder, and Circuit 37 will be connected to it, as shown below. Or, if you have the trailering option or a DRW truck you may have a power stud on the firewall with Circuit #37 connected to it. In any case you can connect to that circuit to get battery power for the ignition. However, you should put a fuse, probably a 20a one, in the circuit as that wire uses a fusible link that is capable of far more current than you need for the one-wire distributor.

So if you have that circuit, and you should, then you can connect to it for your HEI. But as that wire is hot at all times you still need the relay. And I'd still fuse it.

You can see a suggested wiring diagram for the relay on that page.

That's a good little write up Gary. 👍

Thanks for the illustration and spelling out where it can be found on the site.

[Gary Lewis]

That's a good little write up Gary. 👍

Thanks for the illustration and spelling out where it can be found on the site.

Welcome, Jim. As the curator of the site I usually know where things are ... buried.

[grumpin]

Welcome!

[shosh86]

Welcome!

Dane, thanks very much.

Y’all know anything about CRT Performance’s distributors? They make an HEI one for the Ford 300. Similar price to the A-Team distributor.

https://crtperformance.com/shop/ols/products/ford-i6-144-170-200-250

[Gary Lewis]

Dane, thanks very much.

Y’all know anything about CRT Performance’s distributors? They make an HEI one for the Ford 300. Similar price to the A-Team distributor.

https://crtperformance.com/shop/ols/products/ford-i6-144-170-200-250

When I encounter things that appear to be the same it suggests to me that they are. I believe that the Chinese buy an original, reverse engineer it, and then hand out the plans to a manufacturer who makes them and then markets them under several different brands. In other words, since many of the spec's are the same I'd bet they are the same.

I ran into this several years ago with a lathe/mill/drill I wanted to buy. Harbor Freight made one that was fairly well liked so I bought it. But one specialty tee-nut was bad on the one I got so I pulled out the drawings to find the part number. Lo and behold the drawings were wrong. It was a completely different part and the way that nut was drawn was wonky. Like the drawing we did in drafting where it was impossible to make.

So I called HF customer support and got no where. The young lady I drew had never seen one of those machines much less used one, and couldn't read a CAD drawing. So I did some research and learned that several others sold essentially the same machine, including Busy Bee and Grizzly. I downloaded the Busy Bee manual and it had the exact same error. I downloaded the Grizzly manual and it had the exact same error.

Given that I called Grizzly and when I told the gentleman that answered what part was bad he said "Let me pull the drawings and find the part number." I waited and then I heard "You can't even make that part!" And I laughed. So he said "I'm going to go take one of those apart and find out what the part number is and I'll call you back." In 30 minutes he did and said "They are $2, how many do you want? And, we are changing the drawings."

Now I'm a Grizzly customer.