73 455 HEI upgrade question

[gr_speedy]

I bought a HEI distributor set up and i am planning to install it comming days. My question is: usually older cars the cable that goes to the coil they have an internal voltage dropage installed or wired. Any ideas where the cable goes behind the firewall to the inside? Color would help (after the fuse box).
I emailed kimson days ago but it seems he is out so i bought a manual but it will be here next week. If somebody has done this upgrade please give me some advice.

[Robroy]

I bought a HEI distributor set up and i am planning to install it comming days. My question is: usually older cars the cable that goes to the coil they have an internal voltage dropage installed or wired. Any ideas where the cable goes behind the firewall to the inside? Color would help (after the fuse box).
I emailed kimson days ago but it seems he is out so i bought a manual but it will be here next week. If somebody has done this upgrade please give me some advice.
I’m after the same info since I’m gone install a Crane XR-I set (pointer replacement)…

[dewbers]

That makes three of us. My rebuilt carb goes back on today! ( I HOPE )
Then next week, we're tackling the HEI. Will someone just do it so the rest of us can learn from you or your mistakes!!! :beers:

[gr_speedy]

Per i was gonna do the same but i added the crane, the coil, the wires, cups rotor finger, plus with all the trouble i would also need a new distributor and in the end i figured few bucks more i can get the HEI. I got this set on eBay from a guy that bought all parts new never installed them and sold the car. With shipping i paid $140.

[gr_speedy]

Well i got the Manual CD today :beers: (few min ago). Steve is says 73 Centurion but i guess it should be the same for 71 72. You will also have some patience to tell you how to do it....... got to replace the engine on my wifes Civic this coming week. Looks like you have to cut the cable before the resistor wire and wire it to the HEI directly. Also disregard the wiring split that goes to the starter you don't need it for HEI. This is how it looks...... resistor is shown outside the firewall and not on the inside of the car. BUT i'll know for sure the currency of the wire after i start on it. :spank:

[gr_speedy]

Manual pic

[Robroy]

Wonder what kind of resistor it is being only 1.8 ohm…? Thinking it could be the cable itself that’s design to keep this resistance …hm
If you find it please shot a pict of it and post…:user:

[gr_speedy]

Wonder what kind of resistor it is being only 1.8 ohm…? Thinking it could be the cable itself that’s design to keep this resistance …hm
If you find it please shot a pict of it and post…:user:

Per after reading a little the manual it also only supplies the coil with 5-5.5 Volts. HEI needs pure 12Volts.

[gr_speedy]

Steve and whoever wants to upgrade to HEI i figured the wiring out.
Manual says braided wire (thats the resistor wire) is somewhere after the firewall. Actually it starts from the firewall and it goes till the right valve cover where it splices to a yellow one (starter) and the pink one that goes to the coil. You can take the yellow wire out no need for HEI. I went ahead and cut the braided wire from the firewall. Next picture shows where i pulled the wire inside the car: there was already a rubber opening for the vacuum hose and there i put the wire also. The whole point is to get juice directly from the ignition module and not mess with the junction box, plus i wasn't sure if the braided wire was behind the firewall. Next picture shows the wire that i pulled (12 gauge) and the PINK from the module. tape the 2 wires together.You will have to lower the column to get access. Connect it and your wiring setup for HEI is done.

[Robroy]

Steve and whoever wants to upgrade to HEI i figured the wiring out.
Manual says braided wire (thats the resistor wire) is somewhere after the firewall. Actually it starts from the firewall and it goes till the right valve cover where it splices to a yellow one (starter) and the pink one that goes to the coil. You can take the yellow wire out no need for HEI. I went ahead and cut the braided wire from the firewall. Next picture shows where i pulled the wire inside the car: there was already a rubber opening for the vacuum hose and there i put the wire also. The whole point is to get juice directly from the ignition module and not mess with the junction box, plus i wasn't sure if the braided wire was behind the firewall. Next picture shows the wire that i pulled (12 gauge) and the PINK from the module. tape the 2 wires together.You will have to lower the column to get access. Connect it and your wiring setup for HEI is done.
Thanks for sharing this Foti! :xyxthumbs:

Hm….Let’s see if I got this right,
you removed the yellow wire to the starter completely, right?

Then you removed the resistor cable that split up to yellow and purple near the right valve cover.
You kept the purple wire (from the coil) and extended it and ran it through the firewall and then hooked it up with purple wire on the other side of the firewall, which is the one going to the ignition switch.

I guess one could supply the coil anyway you want as long as it gets 12V and the power goes on and off with the ignition switch(key), but the most proper way seems doing something like you have done here.

[gr_speedy]

Per, yellow (to starter) all gone. I didn't keep the exsisting pink wire because it was very small. I run a totally new wire FROM the ignition switch/module directly to the HEI. I run a 12 gauge (double the size from the pink one) red wire. Per i am not sure if you need to do that since you only add the Crane to the distributor. Adam i remember he said that he did the crane to Rolfs car. I would ask Adam if he had to run a new wire.

[Smartin]

The Crane XR-i is a simple direct wire-in. Two wires come off the unit - one goes to the + side of the coil, and the other goes to the - side.

[Robroy]

The Crane XR-i is a simple direct wire-in. Two wires come off the unit - one goes to the + side of the coil, and the other goes to the - side.
That sounds simple enough, but I guess it’s still a good idea to replace those resistor wires and run 12 V to the coil....or?
If I got it right the resistance was to keep the pointers to last longer…

[Smartin]

I would recommend whatever the instructions on the crane kit tell you to do. The crane kit is a direct replacement for the points. Don't assume you will need more voltage to the coil. It could cause failure of the crane unit.

[Robroy]

I would recommend whatever the instructions on the crane kit tell you to do. The crane kit is a direct replacement for the points. Don't assume you will need more voltage to the coil. It could cause failure of the crane unit.
You are dead on right Adam,
I studied the instructions this morning and it clearly states “The XR-I requires ballast resistance to limit coil current”. It also said that most installation problems were due to improper ballast resistance.

As you indicated this is a replacement component designed as a “Plug & Play solution”, I got things mixed up with the HEI :rolleyes: .

To check the factory resistance they recommend to
1. disconnect the coil –
2. switch on the ignition
3. connect a voltmeter with the + to the + on the coil and the – to the ground, should show 12V there
4. then momentarily ground the – on the coil, the meter should then drop below 8V if the resistance is OK

Added a little later:
They also hinted that some after market coils could have an integrated resistor…