56 chev divorced coil distrubter

[craig57]

i have purchased a 1980 small block divoced coil distributer as suggested to elinmate the need for the firewall alteration on the 1956 chev belair, but not sure what the other four elecrical wire connectors are required for on the distributer I figure they have something to do with the computer on the 1980 small blocks
Im wondering does this requlate the advance in the distrubuter and if so what do they get hooked up two, or do I simply ignor these four wires and just worry about the two wire terminal on the distributer that are straight forward

[MrPbody]

First off, 1980 small block had the HEI (High Energy Ignition) distributor w/integral coil. No computer in a 1980. '81 was the first year. The distributors are easily identified as the pre-81s have a vacuum advance "can" and the computer-controlled do not.

ALL '56 V8s had a "divorced" coil. They used "points" as a trigger instead of a magnetic "pickup" like the electronic units of more recent times.

If using an HEI (Large diameter cap., coil "in cap"), there is only one external wire "hookup". A 12V "switched" source plugged into the "BAT" terminal, make sure it doesn't have a "ballast resistor" in-line, and is at least 14 ga (12 is better). The points-type coil needs only 8V to operate correctly. This prevents the points from "burning" by too much current going through them.

I hope I'm reading your post correctly, as some of what you've said doesn't "jive" with my experience.

Jim

[Ol'Jim]

Craig, are you sure your new dizzy is from a 1980 Chevy? I know they did make some HEI units with a separate coil and the smaller cap, but I thought that was later, (like in the 87-92 Camaro's, etc). Those were definitely computer-controlled, and had 2 small oval-shaped connectors sticking out the side of the dist.

The coil-in-cap units had a small wiring harness that exited the base of the dist, and ran up to the cap, (this was for the electronic ignition module, which resides in the base under the rotor). You must retain that connection, and the only external connection you need, as MrPBody stated, is the switched 12v source to the "B+" or "Batt" terminal on the Cap connector. You can hook a tachometer to the "Tach" terminal.

[craig57]

finally getting back I am aware of the difference between the large cap coil mounted distributer but back in jan feb some one suggested to go to a Chev 80 or 81 HEI distributer cause it had a smaller cap and a seperate mounted coil. This is suppose to eliminate the fire wall modification for the older large cap HEI. the one I will be attempting to install does have the the two oval connectors I believe one has two wires and one has four wires if I remember right
I was hoping how ever suggested this or if any one might be able to explain if the four wire one was needed and our is the advance that is controlled by the computer.
This being droped in to a 283 stock engine If the body man ever gets finished

[MT-2500]

Originally Posted by craig57

finally getting back I am aware of the difference between the large cap coil mounted distributer but back in jan feb some one suggested to go to a Chev 80 or 81 HEI distributer cause it had a smaller cap and a seperate mounted coil. This is suppose to eliminate the fire wall modification for the older large cap HEI. the one I will be attempting to install does have the the two oval connectors I believe one has two wires and one has four wires if I remember right
I was hoping how ever suggested this or if any one might be able to explain if the four wire one was needed and our is the advance that is controlled by the computer.
This being droped in to a 283 stock engine If the body man ever gets finished

Get one for a 76-80 years and the advance will be vacuum on outside of dist.
Just wire up 12 volt ign wire to dist and you are set to go.
And with tack there is a tack terminal beside ign terminal.

You might consider some new /different no. spark plugs to take the more hot HEI ing spark.

[craig57]

thanks for the reply. If im understanding you right I know the oval two wire is to power coil and tack if i rember right, sounds like the four wire is to control pcm and this will be rquired for proper operation advance of distrubeter and timing
Sounds like it may not be possible to do as suggested. I,ll have to find my old post and inquire the the person how suggested this.

[craig57]

Yes ur right went back to my old post and it was an 87 and up that was suggested
The distributer has the two oval ports. it sounds like this will require the pcm to operate properly if im understanding correctly

[MrPbody]

A MUCH "smarter" (IMO) choice to accomplish the same "end" would be to install an electronic conversion "kit" in an old points distributor. We prefer the Crane "XRi" system, since it's self-contained and has a built-in rev limiter (fully adjustable).

This would avoid all the computer issues involved, and provide a "stock look". Much less expensive, too.

Jim