HEI conversion time...

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kursplat

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so the ignition module in my 74' swinger is starting to die. car is bone stock 318 w' aound 70,000mi. the module, (OEM one bled out a while ago), is a replacment that i had salvaged from my deceased motorhome. it's gone from missing at a 2500 rpm after driving it for 15 or 20 min to also having a low rpm miss all the time. i considered just throwing a new Standard BlueStreak at it, but that's just too simple...and no fun :D
 

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i’ve got a pretty good collection of old computer heat sinks so I decided to save some $$, and wrecking yard hopping (too hot here lately). decided to go with the all aluminum one on the right. it's going to be mounted near where the stock unit used to reside, so i bent up a bracket from some scrap aluminum, and drilled to use some existing holes...
 

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this one has enough meat in the base to drill and tap into.
 

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i'm doing this straight from SlantSixDan's instructions and just buying the parts recommended, mostly through NAPA, but i am getting the coil and wiring harness from RockAuto.

http://slantsix.org/forum/viewtopic.php?t=15779

the dog noticed it was getting pretty warm out so we're going to take a break until it cools down later :drinkers:
 

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That is some major league cooling capacity. I used the GM 8-pin module on my slant since it has Metripak connectors, plus allows computer control (optional). I put it on a much smaller CPU heat sink on the inner fender. If you see where GM mounted them, it should work fine. Theirs were inside the distributor at the top rear of the V-8 engine, which is a hot area.
 
...If you see where GM mounted them, it should work fine. Theirs were inside the distributor at the top rear of the V-8 engine, which is a hot area.
ya, i always thought that was a strange place, i don't even like the coil on the motor...guess the exhaust manifold would have been over the edge :happy3:
 
I didn't even use a sink on mine. Someone on my 67 had already drilled a couple of holes up under and on pass side of wiper, which is a flat area of the firewall. One of the screws they used to mount the old ECU was small, so I used it to mount the HEI, and drilled one more hole. I used thermal grease, of course. So far, two hot summers has not let me down. I do carry a spare.
 
I didn't even use a sink on mine. Someone on my 67 had already drilled a couple of holes up under and on pass side of wiper, which is a flat area of the firewall...

ya, this one is as much about having fun making it as anything :thumrigh:

test fitted the heat sink and module to the bracket
 

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holy overkill on the heat sink. LOL. you wont have to worry about it getting warm
 
I doubt you can overcool an IC, but in-distributor HEI modules are designed to operate at 80-100 deg C.
 
That very nice I used this one Complete HEI Kits for Sale (
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1 2) Works great and I dont have the imagination to create ones like yours, I love the way it starts now on hot restarts.
 
I went with the D.U.I. 6 pack set up. I like the HEI ignitions.
 
On the far end of the scale, this is what you can get away with. The former owner had a Mopar ECU mounted here on the flat between the heater and wiper motor. They had already penetrated with on small sheet metal screw, so I used on of those holes and drilled another. I did use thermal grease, and had intended to add a separate ground lead under the screw holes, but just the other day I checked the ground integrity and it's OK.

B+ and the tach both come off the coil terminals. I've run this coil now through 2 summers with no ballast, a stock Mopar coil, with no ill effects. On a simple, mild, low compression street engine I see no reason for the fancy, expensive, E core and other "big" coils.
 

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On the far end of the scale, this is what you can get away with. The former owner had a Mopar ECU mounted here on the flat between the heater and wiper motor... I've run this coil now through 2 summers with no ballast, a stock Mopar coil, with no ill effects. On a simple, mild, low compression street engine I see no reason for the fancy, expensive, E core and other "big" coils.
i love seeing how less than optimal these things can be mounted :smile:

well i got everything hooked up and it fired right up, even got lucky on the distributor wires ;) i unwraped about half the engine wiring to remove the wires that got abandoned and got most of it cut clear before i had to go to work today. looks like the OEM coil was starting to weep a little. glad i changed it out too. with the plugs regapped to 45 it's runnin' just fine.
just need to rewrap the wiring and mount the relay so it's not flopping around in there.
as this is my daily driver, it's nice having something easy to work on with parts available pretty much anywhere
 
Please post the link to the coil and harness.. Sounds like a solid installation that should make it to the next ice age. :). .

Man that HEI is just friggin great. Its great cause its small form factor and like posted above, you can use anything for heat sink. Firewall, fenderwell, butter knife.

I was trying to get my neighbor to run it on his points ford truck, supposedly you can trigger hei with points too.
I ran a pair of generic napa gm hei modules on a dual coil 4 cyl kawasaki 650 back in the college years. I didnt know about heat sink then but I reckon it didnt need it cause it ran great.
 
so after driving this for a few days, i'm really happy with it. starting is the same, car never did have any trouble with that. smoothed out the idle and missing though. i haven't tracked the mileage yet, speedo's off a little, but i am getting about 1/2 a tank or so more out of it going to work and back.
i was pressed for time when i did the cut over, so i did a quick and dirty bracket for the coil. just a couple pieces of aluminum bent up using existing holes. works fine, just looks like crap ;)
also removed most of the left over wires that aren't needed and just need to re-wrap the wiring.
 

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Here's one of the kits I build.
And yes, they do add some get up and go.
 

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Here's one of the kits I build.
And yes, they do add some get up and go.
clean install :glasses7: i'm hoping to have time this weekend to clean mine up but my end up starting a new project...why finish one when i can have lots of half finished things goin'...:violent1:
 
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