Here’s the myth:
If a car has a points type ignition, you can pull the wire that runs from the distributor cap to the coil and replace it with an old piece of vacuum hose and the car will start and run for a few minutes. The key being that the vacuum hose be well used. The theory being that the carbon build up in the hose will carry an electrical charge. This will allow the car to start and run until the carbon is burned off.
Can anyone confirm this?
My friends and I used to do this trick about 25 years ago. But now all my cars have electronic ignitions, and I cannot replicate. But I’ve seen it work on a 1969 Cougar, 1970 Mustang, 1972 Maverick and an early 70’s Chevy.
If anyone here doesn’t think I’m crazy, please reply.
Thank You,
Bill
I can see it working on points type ignition system and if the hose has enough carbon-black in it. These were dumb ignition systems and would try to create a spark no matter what. And since the secondary ignition system is a high voltage/low current system, I can see this working because there’s the carbon-black in the hose to conduct the high voltage, but very little current to burn the hose up.
Tester
It seems you say you have done it yet your asking if it can be done. Did i read this wrong
Sure why not, but why the heck would any one try it. Shirley their must be an old plug wire somewhere you could use. My old shop teacher used a cork and paper clip to fashion a rotor while stuck somewhere in Africa, most times one does not need to resort to such extreme measures.
Yes it works and the hose does not need to be old. This one cost me some brews about 30 years ago. No real explaination given why it works. (I was thinking ionization of the air inside the tubing made it conductive)
If you’ve already done it on multiple occasions, how is it a myth?
More importantly, WHY would you do it?
Who keeps old pieces of vacuum hoses laying around?
I don’t consider Tester to be old but he’s correct about the carbon black. This stuff is used in the manufacture of plug wires along with rubber hoses, tires, and a thousand other things.
Odds are this stuff is forming a coating on the inside of an aged hose and conducting a spark. Eventually it burns off enough that a spark won’t be carried.
There’s a carbon black plant about 10 miles down the road and several miles out of a small town from me and they ship out rail car after rail car of this stuff.
The people who have a swimming pool and are downwind of this place are not overly enthused though.
You have a spark that will follow the path of least resistance. A charge strong enough can go through air, lightning as an example. There is evidently less resistance in carbon black, and possibly air than a rubber vacuum hose.
Why would the inside of your vacuum hose be coated with carbon black? Mine isn’t.
Where would it come from? Been using your vacuum as a fireplace?
Carbon black is a common filler material in automotive rubber products…including tires. Pure “rubber” polymer liquid is actually a translucent amber color. Adding carbon black to it improves its mechanical properties, and turns it black.
Carbon is a not bad conductor of electricity.
Got it. I actually realized it myself after I shut down last night.
Yeah, anyone who’s looked at how a microphone works knows this.
Thinking about it, I can see where a high voltage spike could travel through a carbon-impregnated passage. It just sounds wierd because I’ve never heard of this trick before.
Except when it’s a diamond.
As I understand it, this also holds true for tires, and is why in some cars you’ll get a static electricity shock when you get in/out of them.
If you have high-carbon tires, any static buildup is transmitted to the ground, so when you touch the door frame, you won’t get shocked. Some newer tires have silicon instead of carbon, and electrically insulate the car; when you touch the door frame on those cars, you get to play “ground strap”, meaning that the static buildup in your car discharges through your body instead of the tires.
There is a way to stop this. When you get out of cars that shock you, grasp the door frame before you put your foot on the ground. Why this works is that the contact area on your fingertip is small, so you’ll feel the current go through the smallest patch. If the last contact is your foot, the contact area is large – so you’re still grounding the car, but you won’t feel it.
So yeah, I can see how using some types of rubber tubing would work like a wire.
Have also seen this done with a GM distributorless ignition system where the coils are on top. Not a myth.