Installing points conversion, and HEI System function, tests, and modification.

I'm writing this because this is a frequently asked question (FAQ) on V8, and one of the first modifications owners make to an older car, is to replace the points. The points ignition has been around for a long time, and is very reliable, and easy to work on (GM), but it isn't maintenance free. Despite all the hype out there, there is no performance to be gained by replacing points in most stock and mild combinations. There may be some drive ability gains from a hotter ignition, including faster starts, and longer spark plug life including resistance to fouling.


This is how the stock points system works. Extending from the firewall engine harness connector(below the brake booster), is a calibrated length of special resistance wire. This wire does not extend all the way to the positive side of the coil. In the harness, it is joined by a wire leading from the "R" terminal of the starter solenoid, and from there, it extends to the positive side of the coil. There is a shorting switch inside the starter solenoid. When the starter motor is cranking the engine to start, the shorting switch inside the solenoid, sends battery voltage through the yellow wire to the coil positive, effectively bypassing the resistance wire. Once the engine starts, and the key is released to the run position, the yellow wire ceases to supply voltage, and voltage flows from the firewall via the resistance wire. This drops the running voltage so that point life is maximized.

To test the system for proper functioning requires a volt meter. Connect the voltmeter between the positive side of the coil and ground. Turn the ignition switch to the run position. The reading should be 5.0-5.5 volts. It is important that the ignition points be closed for this test. If the points are open, the voltmeter reading will be full battery voltage. Bump the engine over until the points are closed, and check again. Again, 5.0-5.5 volts is the normal reading with the engine stopped, ignition key in the run position, and the voltmeter connected between the positive side of the coil and ground. The second part of the functionality test requires that you pull the coil wire out of the distributor, and ground it so the engine will not start. With voltmeter connected as before, crank the engine continuously, and observe the voltmeter. The reading should jump from the previous 5-5.5 volt reading up to 9 volts minimum. If it does not, it indicates a problem with the shorting switch inside the starter solenoid, or a wiring problem between the "R" terminal of the solenoid, and the coil. This will result in hard starting when cold.

If you are installing a points conversion, it is important to READ the instructions and determine if the system requires full battery voltage, or if it needs resistance on the primary side of the ignition. If it requires resistance, you can leave the stock resistance wire in place, or add a ballast resistor if the stock resistance wire has been replaced sometime in the past by you or a previous owner. In any case, if you cannot use the stock wiring including the resistance wire, you either have to run another wire that carries ignition on battery voltage, or you need to remove and replace the resistance wire including the wire from the starter solenoid. The right way IMHO, is to remove and replace the wiring. The easiest way to do this is to open the wrapping on the engine wiring harness. Then remove the bolt in the center of the engine harness connector at the firewall, and unplug the front half of the connector. The wires push in from the front with a metal "barb type" of connection. The barb can be compressed with thin nose pliers, and the wire will pull out from the front. Then you simply unsolder the the barb connection and attach it to a length of 14 gauge wire, and snap it back in to the firewall connector, and plug the connector back onto the firewall, tightening the bolt. Run the wire along the harness, crimp on the proper connection, and attach it to the positive side of the coil. Most if not all Pertronix, need full time battery voltage. GM large cap HEI distributors need full time battery voltage.

Below is a picture and link for the barb type terminal that clips into the front half of the the engine harness connection at the firewall.

https://www.amazon.com/Packard-16-1...coding=UTF8&psc=1&refRID=92WM5X14KNTD61WB0EXZ

 

See the Power Timing thread in this Forum.

 

Just as an FYI, the connectors used in our cars are called, "Packard 56" terminals and connectors. The one in question is called a "split tab male terminal". They are readily available if you Google it. Plus its a real PITA to uncrimped those connectors. If you have a notion that you might one day convert your car back to stock, I would suggest you leave the resistance wire in the harness, and just remove the resistance wire terminal from the bulkhead connector and tape it off. Get a new Packard 56 terminal and install it with a new wire crimped in place. That way the resistance wire is there, still in the harness and can be converted back to points easily. I did this with my black 71 as I have an MSD setup in it. Even in its modified state, I have cut anything up on that car.

 

Spencer,
The resistance wire is hot in the crank, and run positions. You can confirm that by simply connecting a voltmeter between coil positive and ground as described in the first post of this thread. The solenoid wire bypasses the resistance wire during cranking. Again, you can confirm this by running the test described in my first post. No harm in leaving the solenoid wire in place, but most people remove it along with the resistance wire. It's kind of redundant when replacing the resistance wire.


If you see yourself possibly going back to points one day, do as Jason describes. Leave the wire in the harness taped off.

 

The resistor wire and the wire from the R terminal of the starter solenoid are joined together. The wire from the solenoid is the bypass to the resistance wire. The resistance wire extends from the firewall for a calibrated length, and then the bypass wire attaches to the end of the resistance wire and continues to the + side of the coil. You have to cut open the harness and you can remove the whole thing. Replace it from the firewall directly to the HEI feed with a length of 12 or 14 gauge wire.

As far as removing any voltage regulator wires, I don't think that is advisable or necessary. I'd leave that alone. I converted my stock 70 alternator to a 12 SI 94 AMP internally regulated alternator . All you need to do is bridge 2 wires on the regulator plug, and move one wire from the 2 wire plug into the alternator. I got the Alternator from Jamie on this board. I would direct a PM to him about wiring modification. Here is the thread,

http://www.v8buick.com/index.php?threads/89861

 

Depends on the distributor and everything else about your combination. More information, way more

 

Steve, first, there is no difference between 350 and 455 point wiring except possibly the length of wiring, maybe not even that. Second, there is no reason to even touch any wiring inside the car whatsoever. If I thought a diagram would help, I'd draw you one. Fact is, it's really very simple. All you need to do is first, open up the engine harness. They are usually wrapped in tape. Cut it open. Then find the lead that is attached to the + side of the points coil. Trace and isolate that wire all the way back to the firewall. Mark the wire where it goes into the firewall connector. Then remove the bolt in the center of that connector. Once you do that, you can unplug the entire connector. Remove the wire you marked by compressing the barb, and pulling the wire out from the front. Then replace it with a suitable length of 12 gauge wire, and run that to your HEI BATT lead. That is it. Year One makes a ready made wire with the barb on one end and the HEI plug on the other. It's part # L00510. It doesn't get any easier than that. Some guys want to run another wire from the fuse block, use relays, and make it more complicated. That isn't the way I have always done it. Here is the Year One HEI lead. Plug and play.

https://www.yearone.com/Product/1964-72-skylark-gs/l00510

 

Should work.

 

Yes, remove the wire to the starter. When you remove it from the firewall connector, save the entire thing in case you ever want to go back to points. The braided wire is the resistance wire.