Silly question, but I’ll ask it anyway.

heaudio12329 posts03-03-2020 4:58pmI am not aware of any fixed resistor in ages, and copper, not in forever except for racing, and even then you want to control the 
Most domestic wire is not simply a fiber glass core covered in carbon filled latex. Most are variable spaced fairly high resistance stainless wire. They variable spacing is so they can have consistent performance independent of wire length, hence why today you buy vehicle specific wire sets (or should).
Don't pick some random site on the web for your information. Most mechanics won't have a clue about the inner working of spark plug wires.

And you are a mechanic? I am. The reason for the carbon wire is radio interference, primarily emergency. You can still tell when someone is running multi strand wire, pull up beside them you'll hear it through your AM or FM radio stations. Most hot rodders that have MS wire DON'T have or use a stereo while running.  The old MS wire was OK speaker wire at best. A LOT of insulation for HIGH voltage 15-25 for the old point/condenser style, and 50+ for HEI, can really bite you.

Better off insulating a piece of solder, hee hee.  I mean where do you people come up with these ideas? LOL 

It's the thought that count's RIGHT..

spark to prevent fuel cavitation.

Cavitation in a hydraulic term referring to a pressure drop on the suction side of a hydraulic pump, where pockets of current atmosphere, form bubbles. Those bubbles actually collapse and carve out the cavity pre chamber to a pump. Same with hydraulic Motors, You can hear cavitation..tearing up a pump.. restricted lines, pump and motor killers.

The spark is controlled to prevent air/fuel PRE DETONATION. ..A fuel KNOCK or RATTLE is caused normally by a carbon build up that gets so hot it PRE DET. due to excessive advanced timing (BTDC) a Fuel rattle. Shutting off an continuing to run (DIESELING), again glowing carbon, particles with a fuel and air supply, BUT NO controlled spark, Firing under pressure, dieseling.

The definition of a diesel is simple 2300 psi, it will not be a diesel without it.  NOTHING ELSE.. 2300 psi.. You can obtain 2300 psi a few different ways... Different story..... See learn something every day...

I know I use to teach engines gas/diesel 101 201, 301. Yup yup
That was a while back...NOT MOTORS ok....ENGINES..

Regards

Work best with Audioengine speakers while listening to a certain Traffic album.
Love the time machine humor.

Spark plug wires are not suited for audio.  They come mostly with resistive material  that inhibits  RF so it does not cause popping sounds in the car radio.

oldhvymec,
When I need some help with RF design or mitigating RF noise, I don't consult my mechanic. Ditto when I need help with fluid dynamics.

"Still using multi-strand wire" ? .... I think your knowledge is either limited or out of date w.r.t. spark plug wires. Modern high performance spark plug wires are a single strand of typically thin stainless wire coiled (variable spacing) around a core of fibreglass or similar, but sometimes around a secondary conductive core of carbon. The stainless wire being thin is resistive, just like a carbon conductor, but you also have a helpful and controllable inductive component, plus as you can space the coils, you can better control conductivity over length.  From the NGK website for example, "NGK ignition wire sets are engineered to meet strict OEM tolerances using variable pitch wire winding, creating resistance to radio frequency interference."  You can also consult the image on this page:  https://www.holley.com/blog/post/plug_wires_build_them_right/, or this one: https://www.musclecardiy.com/wp-content/uploads/2016/05/107.jpg.  With modern cars having high output per displacement, and fuel efficiency/emissions requirements, advanced construction like this is now common.

cavitation: Rapid forming and collapsing of vapour pockets, sort of like on the wall of a moving diesel cylinder, but hey.

The definition of diesel is rapidly heated air reaching a suitable temperature to ignite fuel, but hey, why get hung up on semantics. That of course differs from dieseling where you do have heating due to compression, but can have a lower ignition temperature due to the hot spot in the combustion chamber.  2300psi is a relatively meaningless number that represents a very specific set of conditions w.r.t. initial air temperature and fuel type. It is not, in any way, form, or function a definition of "diesel"   (nor have anything to do with this conversation).

This is true about dieseling and in fact if you put a drop of oil on the back of a high performance air gun pellet, the heat generated by the rapidly compressed air in the chamber will ignite the spot of oil and increase the pressure of the shot..., maybe to the point of splitting the barrel.

https://youtu.be/yyfxinhOQxs