47 V8 ignition mystery

[Als48]

Craig, Is there any way to tell if your distributor cap is seating properly? I had a cap once that failed to seat correctly and it caused the exact problem you are seeing. It seemed to be cocked slightly when attached, causing the rotor to not fire two of the cylinders due to an enlarged gap at some of the inner terminals. That would also cause the rotor to be too close to some of the other terminals, which might cause the rotor to make contact and loosen the brass tip, as you have seen. Possible?

Al Hook

[Jack E/NJ]

^^^
2x

[1942deluxe]

Al, really good suggestion. I have NOS Ford on mine which fit really well but I've read the aftermarket caps may need modified slightly to fit correctly.

[Old Henry]

Originally Posted by Mart

While respecting your desire to keep all original, the overriding aim is to fix the problem. If you try the crab type cap and rotor and no conduits and it is then perfectly ok, you can then have more confidence when troubleshooting. You can then try and reintroduce the original parts step by step until the problem comes back. the last thing you replaced will be the problem item.

Changing the cap and leads to the crab type will be a valuable troubleshooting tool.

Temporarily changing away from stock as a diagnostic tool is not a bad thing.

I await with interest what you find.

Mart.

I had all of those same thoughts yesterday and will resort to that if necessary.

[Old Henry]

Originally Posted by Als48

Craig, Is there any way to tell if your distributor cap is seating properly? I had a cap once that failed to seat correctly and it caused the exact problem you are seeing. It seemed to be cocked slightly when attached, causing the rotor to not fire two of the cylinders due to an enlarged gap at some of the inner terminals. That would also cause the rotor to be too close to some of the other terminals, which might cause the rotor to make contact and loosen the brass tip, as you have seen. Possible?

Al Hook

I will check that. Makes sense that could be the problem.

[Old Henry]

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Here's something that doesn't seem right to me but may be normal.
Everywhere any of these new sparkplug wires I just installed are bent the outer layer of insulation is cracked. (See photos) Such is particularly so inside the distributor cap where they are really bent. Is that normal or could it cause a problem?

[petehoovie]

Originally Posted by Old Henry

Here's something that doesn't seem right to me but may be normal.
Everywhere any of these new sparkplug wires I just installed are bent the outer layer of insulation is cracked. (See photos) Such is particularly so inside the distributor cap where they are really bent. Is that normal or could it cause a problem?

"new sparkplug wires"???

[Brian]

There's your problem! I know you've metered your leads at zero ohms, however the HT current is going to take path of least resistance. These cracks in the insulation provide the escape route for the current. use decent leads.

[Old Henry]

Originally Posted by Brian

There's your problem! I know you've metered your leads at zero ohms, however the HT current is going to take path of least resistance. These cracks in the insulation provide the escape route for the current. use decent leads.

I bought these spark plug wires from CW Moss. Is there any better place to buy them to get a better product? I've just emailed CW Moss about the problem and hope they do the right thing and replace them with better or refund my money so I can find better.

[1942deluxe]

Craig, those look like the Dennis Carpenter wires I have on both my 42 and 48. Mine cracked slightly but nowhere near the extent yours are. I lubed mine with either WD 40 or silicone spray during the installation. The original wires were brown 46-48.

[jimTN]

You definitely would be better off with the crap setup. You will need a new rotor for the crab, the crab cap and the snaps & pins to attach it. Most vendors carry all of it. No sharp bends with the crab.

[Old Henry]

Originally Posted by 1942deluxe

Craig, those look like the Dennis Carpenter wires I have on both my 42 and 48. Mine cracked slightly but nowhere near the extent yours are. I lubed mine with either WD 40 or silicone spray during the installation. The original wires were brown 46-48.

Yes. They do look identical to the ones being sold on Dennis Carpenter's site. Maybe they're better than the CW Moss ones. I'll probably wait to see what CW Moss is going to do to decide.

[Old Henry]

This was duplicate of previous so deleted.

[tubman]

Packard 440 from "The Brillman Company". If that works, you've found the problem and can work forwards on getting the crappy reproduction wires to work.

[j ripper]

Belden 7mm metallic core wire from Napa Auto parts is my go to. Buy X amount of feet and necessary terminals and make my own.

[Bored&Stroked]

I always make my own wires - because at least I then know the quality of the wire that I buy as well as the conductor ends.

I've used Packard 440 for years, but might look at the Belden 7mm metallic core wire that was mentioned up above. You can purchase high-quality ends from a variety of places. I buy the high-quality ends from MSD or Taylor (I'm sure others have them) - and crimp them with the proper dies/pliers.

If I saw those cracks in my wires, I'd be concerned and would not be running them. Also, as a test, you can make ONE wire and replace the existing ones for the cylinders that are not firing and see if you see a change.

If you're running the steel spark plug wire tubes (with the wires inside of them) - then the quality of the wire is SUPER important. Having all four wires running through steel tubes requires that the wires absolutely have no chance for leakage.

Best of luck!

[Old Henry]

Originally Posted by j ripper

Belden 7mm metallic core wire from Napa Auto parts is my go to. Buy X amount of feet and necessary terminals and make my own.

Originally Posted by Bored&Stroked

I always make my own wires - because at least I then know the quality of the wire that I buy as well as the conductor ends.

I've used Packard 440 for years, but might look at the Belden 7mm metallic core wire that was mentioned up above. You can purchase high-quality ends from a variety of places. I buy the high-quality ends from MSD or Taylor (I'm sure others have them) - and crimp them with the proper dies/pliers.


Best of luck!

Thanks for the suggestion to make my own. I don't have any problem with the idea as long as they can be authentic so have two questions:

1) Can the authentic cotton braid copper core wire with the smooth brown outer surface with no writing be bought by the foot anywhere? (I haven't been able to find it anywhere.)

2) Are the soldered ends that go into the distributor cap available. (I haven't been able to find them.) Those can not be crimped on. They must be soldered on. (See photo)

[Old Henry]

Originally Posted by Bored&Stroked

. . . as a test, you can make ONE wire and replace the existing ones for the cylinders that are not firing and see if you see a change.

Unfortunately, with my stock 47 rabbit ears distributor cap I can't just change one wire without disassembling the entire wire loom.

[petehoovie]

Originally Posted by Old Henry

Thanks for the suggestion to make my own. I don't have any problem with the idea as long as they can be authentic so have two questions:

1) Can the authentic cotton braid copper core wire with the smooth brown outer surface with no writing be bought by the foot anywhere? (I haven't been able to find it anywhere.)

2) Are the soldered ends that go into the distributor cap available. (I haven't been able to find them.) Those can not be crimped on. They must be soldered on. (See photo)

[FortyNiner]

Originally Posted by Old Henry

Thanks for the suggestion to make my own. I don't have any problem with the idea as long as they can be authentic so have two questions:

1) Can the authentic cotton braid copper core wire with the smooth brown outer surface with no writing be bought by the foot anywhere? (I haven't been able to find it anywhere.)

2) Are the soldered ends that go into the distributor cap available. (I haven't been able to find them.) Those can not be crimped on. They must be soldered on. (See photo)

Rhode Island Wire has these items: http://riwire.com