egerson

Subject is 1958 distributor cap wires from the spark plugs.

I note that several are barely touching the connector prongs on the distributor. Many can be pulled off with little or no effort. I can easily imagine that a poor connection could in some way interfere with good electrical connectivity, altho I would not know what symptom to watch for as a sign of a connection problem. Except for COLD START problems, she seems to run fairly smoothly once going.

Short of removing the cover plate below the manifold and replacing the entire wiring harness, any suggestions as to how to achieve a better fit and connection? I removed each loose fitting connection and found the brass tip had been wrapped with a thin piece of twisted wire on the ends. I doubt this is the way it came OEM. I tried crimping the brass fitting to tighten, but to no avail.

I had considered taking small pieces of aluminum foil and wrapping the distributor prongs with layers until a firm fit is achieved.

suggestions and other possible options appreciated.
I have included a photo of the top of the distributor, about which I know very little. Can you tell from this photo if this is electronic or manual with points?

Is there a Corvette specific firing order or does that depend on the engine? I was told that the car has a later model 327 Chevy (?Corvette) replacement engine, but I have not been able to find the engine stampings in order to confirm this.

And is there an easy way to determine at the distributor lead is #1 for timing adjustment purposes?

thanks
ED G

ILBMF

That is a much more modern distributor that seems to be clocked 180* out by looking at it from here. #1 cylinder is the driver's side front. You shouldn't see any of the wire brass where the boots are at the cap connections.

JohnZ

That's a 1974-up GM "HEI" (High Energy Ignition) distributor, which has an electronic module inside that replaces the traditional points-and-condenser arrangement used for over 100 years. You also have an aftermarket Edelbrock performance intake manifold designed for the earlier/smaller distributors, which is why they interfere.

All Corvette V-8's have the same firing order (1-8-4-3-6-5-7-2).

Follow the plug wire back from the #1 cylinder (driver's side front), and the other end will be plugged into the #1 cylinder (or what's being used as the #1 cylinder) on your engine.

egerson

Thank you for your impressive knowledge base. You say "which is why they interfere". What do you mean by INTERFERE?
Does that mean that my HEI distributor is not designed to work with my manifold and that this is a BAD match?

What sort of symptoms or running problems might this predispose to?

Is it possible to work with what I have and create a better running situation without "interference?"

What changes would you suggest to resolve the interference and what difference would I be able to perceive if I do so?

thanks
ED

seb67

You can install a distributor such that number one is in any position you want which is most likely why your distributor is in its current configuration. The plugs will follow the firing order regardless of where number one is located. Typically, the distributor vacuum advance can, will be in a position that has it pointing to the passenger side valve cover at the front of the engine as was mentioned, and looking at the distributor from the front of the engine, number one will be the first tower to the right of the vacuum advance can. The tach bat terminal will then be positioned so that it does not come into contact or interfere with the firewall, and will point generally to the drivers side fender. Your HEI may be in its current position because, as was suggested, the manifold may dictate its position for the purpose of clearances of parts of the distributor such as the vacuum advance. The manifold runners may dictate its current orientation (the vacuum advance may hit the runners in other positions limiting opportunity for turning the distributor to time the engine).
This distributor, as was pointed out is an electronic unit that uses a reluctor and magnetic pickup (no points) to turn the integral coil (under the bulge on the top of the cap) off and induce a high voltage output directed through the secondary (plug) wires to the spark plugs. It was introduced as was also mentioned by GM in 1974 on some models and by 1975 it was used on all models. The 1958 ignition would have been a points driven ignition system. Someone has upgraded or installed an HEI on your engine. If they did not bypass the resistor, you should run a full 12 volts to this distributor all the time. If it is running as is, there is no need to re-orient the distributor. You will not gain an advantage by changing distributor orientation.
As to the brass showing at the end of the secondary (spark plug wires), you can slide the boots back from the brass ends so that the ends of the plug wires are exposed and not covered by the boots. Then with some force, push the ends of the wires into the cap. They may seem to snap when they go completely in and you should not see much of the brass ends when fully in the cap. The ends are usually split which allows them to compress as they go into the cap and hold themselves in the cap with outward pressure. With the wires fully seated in the cap, slide the boots back down over the cap towers to cover the towers and brass wire terminal ends. I did notice that it looks as though there is something, maybe solder on the brass. If they are indeed damaged, you may want to just go ahead and replace the set. They are not that expensive. Some HEIs had a plastic ring that snapped down over the top of the cap and helped hold an HEI specific secondary wire set in place at the distributor. Yours may have had one at some point, but is not necessary. The nice thing about the HEI is that once the timing is set, the only thing you will need to be concerned about is the spark plugs, and maybe eventually the plug wires. The plugs may need to be replaced but not very often, as these cars don't tend to see that much use. You can also run a wider plug gap because this ignition system can build more voltage to jump a wider gap, giving a fatter more positive spark. This system is pretty much maintenance free when set up correctly. I'm sure that others may have additional thoughts or opinions that I neglected. I like an electronic ignition system if you are not concerned about "period correctness". Good luck with yours.

Steve

Frankie the Fink

You're dealing with 10s of 1,000s of volts. Don't "jack leg" another Bubba solution with tin foil and paper clips. Get a comparable distributor and new plug wires.

egerson

thanks for all the info and esp the ID on the "1974-up GM "HEI" (High Energy Ignition) distributor."
so here is next question. As I stated, the distributor wire ends do not fit the posts tightly. DO ALL SPARK PLUG --> DISTRIBUTOR WIRES have the same end caps? I realize the wire lengths need to be correct and the plugs have to wire to the correct distributor pins, but does this HEI require any "special" wiring or will standard plug ends fit it?

I do not know yet for sure what engine is in the car, but I assume all Chevy 8 cylinder engines would use the same length plug - distributor wires, bought in a set. Do i need to be concerned about any special plug ends or resistance wires for this HEI or will a generic set of wires work???

Thanks
ED

Powershift

For the most part, I believe the GM HEI distributors used 8 MM plug wires with special ends just for the HEI distributor posts. The HEI distributor has male posts at the distributor, whereas the typical early Chevrolet engines distributor cap had female ends.

You probably need to buy the correct set of 8 MM wires for the HEI distributor that you now have on your engine..........or perhaps locate the correct end connections and install them on your current wires. But this can be a problem if the internal spark plug wiring is not a metal core that can be soldered or crimped.

Larry

Pilot Dan

I agree, the HEI wires have 90* bends on the cap end and are special. You have mismatched items there, and can't expect them to work reliably that way.
If you have "a later 327" as you say, they stopped making the 327 in 68, so it never came originally with HEI. You might want to consider a period correct distributor which will fit that manifold better as well.

Powershift

Here is a picture of an HEI with the correct distributor end caps. Don't pay any attention to the numbers on the wires, however............they can change depending on the installation. Also this is for a 6 cylinder engine, whereas your engine is a V8. But the wire ends look the same. I just did a quick check for you and found this.

http://i55.servimg.com/u/f55/12/85/38/94/hei_di10.jpg

Usually there is a top plastic/Bakelite retaining plate over the top of the distributor to provide additional support to the wires and better hold them in position. It is missing in this pic, but is usually installed. I am sure they can be purchased for a few $ and installed if you have the room in the engine compartment.

Larry

Powershift

Here is an MSD kit for proper ends for the HEI distributor. Jegs or Summit should have................but be sure your existing plug wires have inner cores that can be soldered or crimped.

http://pitstopusa.com/images/F14588426.jpg

Larry

seb67

The information I shared was for a conventional cap (sorry). I forgot that HEI wires are configured differently. The HEI does take a wire where the terminal fits down over the male post on the cap. However, not all HEI wires have a provision for the retaining ring that was mentioned. I have an MSD HEI in a 67 Camaro with a 454 and it has the 8mm wire but with a 90 degree bend as all HEI plug wires, but no provision for the retaining ring and no necessity. I haven't had to do anything to the ignition system since the engine went in the car (that's probably why I forgot about the male-female wire ends). The wires stay on the cap without issue. Your current cap has a provision for the retainer and looks like a stock GM HEI. You should purchase a new set of secondary wires and all should be good (either that or a correct distributor). A picture of your wire ends and the cap without a wire on a terminal would be interesting. They certainly look like they don't belong to each other.

Steve