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confusion about the HEI Relay


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I have an HEI dizzy that I installed using the old green wire constant 12v supply. Is it necessary to use a relay? From what I understand from reading is that it just supplies consistent 12v that my green wire doesn't? I've run it like this for a couple years now before it sat up. If its an advantage I would like to do it, but Im confused at the diagram in the how to.

30amp to battery

87 to power of Dizzy

85 Power in from RUN power

heres where im confussed

86 to ground?

87a to nothing?

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The problem is Government Motors used a 12 or 10 ga wire to power theirs, Ford does not have an ignition feed wire of that gauge. The wiring on these trucks was apparently designed by the 3 stooges.

I have even addded a relay to a Chevrolet C10 that was converted to HEI using a later GM unit from a 250ci 6 cyl. on his 230 ci engine. The factory ignition feed for it was a 16 ga wire so I added a relay and fed it from the starter solenoid stud where GM draws their feeds from.

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There is a convention to "Bosch" cube style relays.

Terminal 30, fused power.

87A power out unless triggered.

87 power WHEN triggered.

85 trigger

86 ground for trigger.

Does this help?

Ok got it all worked out Thanks for all the help. The idle is higher then it was before is that normal?

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Ok got it all worked out Thanks for all the help. The idle is higher then it was before is that normal?

The guys gave you good advice. Glad you got it fixed.

As for the idle, you probably had really weak spark before and should now have a very strong one. That could improve the idle speed by lighting off the mix more reliably. And it may also improve the power and MPG.

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The guys gave you good advice. Glad you got it fixed.

As for the idle, you probably had really weak spark before and should now have a very strong one. That could improve the idle speed by lighting off the mix more reliably. And it may also improve the power and MPG.

Agreed with Gary! 👍

You probably need to warm it up and set the curb idle according to the radiator support sticker.

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Agreed with Gary! 👍

You probably need to warm it up and set the curb idle according to the radiator support sticker.

Ok did that, I set the timing to 10 BTDC as per the sticker Im assuming this is correct even with a HEI. And set the curb idle to 750 It doesn't seem to wanna go any lower like 650 which is what the sticker says, gets pretty low with the AC on but Im happy so far.

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Ok did that, I set the timing to 10 BTDC as per the sticker Im assuming this is correct even with a HEI. And set the curb idle to 750 It doesn't seem to wanna go any lower like 650 which is what the sticker says, gets pretty low with the AC on but Im happy so far.

Do you have a vacuum gauge?

You could try setting the mixture for highest idle.

If the cam timing was straight up I'd say try advancing the ignition to 12-14° BTDC

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Do you have a vacuum gauge?

You could try setting the mixture for highest idle.

If the cam timing was straight up I'd say try advancing the ignition to 12-14° BTDC

What do you mean If? Should I keep it at 10?

I do have a vacuum gauge. You talked me into it.

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What do you mean If? Should I keep it at 10?

I do have a vacuum gauge. You talked me into it.

I don't know what timing set you have in your Bronco.

"If" as in if it has a proper straight up timing chain, then you can consider advancing the ignition timing for more power.

But you don't have an ignition module that automatically retards the timing while cranking.

That may cause laboured starts and kickback.

It will certainly strain the starter and may hurt instead of help.

There's thousands of members here.

I can't possibly remember all their details, and your sig says nothing about a cam or timing gear set....

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