Learn from my ignorance

[PHX65CorsaHT]

Recently change motors in my 65. I had been running a Mark 10 CD ignition on the 110 I pulled. The 140 I put in was recently rebuilt and somewhat modified. Was having a hard time figuring out why it wasn't running well after I hooked up the Mark 10 and changed over the electronic points. Turns out the spark plug cables on the new engine were solid core. Good for autocross when running regular points but not good for electronic ignitions, boosters,etc. Also, not so good for other electrics like the radio. Something about magnetic field generated. Anyway, learning something all the time with my corvair.
So bottom line for most all drivers don't run solid core spark plug cables, particularly if you like the radio and upgraded ignition systems!

[cad-kid]

Thanks for the advice - good info!

[Luke Geis]

I believe it is illegal to use solid core wires for that reason. At least on the street. Not that anyone would know it was you causing the interference. From what I understand there is no advantage these days to using solid core wires.

[Leon Tombong]

Sorry for reviving this thread. I know that it is quite late already and I'm sorry for that. I learned something on this thread. To tell you honestly, I really lacked knowledge when it comes to cars technicalities but I'm doing my best to learn. Anyway, what are the other possible effect of using solid core wires on electronic ignitions and booster? I just want to get some info for that. Thanks!

[bbodie52]

The need for Radio Frequency Interference (RFI) suppression used to be a concern primarily for the interference created by "noisy" automobile ignitions systems that would generate interference with AM radios and television receivers. With modern computer-controlled electronic ignition and electronic fuel injection systems, the on-board engine control computer uses engine sensors to monitor the running condition and status of several important operating parameters of the engine. The computer then continuously adjusts the ignition system and fuel injection system to provide optimum operation as engine conditions and speeds warrant. A high-voltage ignition system is needed to generate a voltage to each spark plug that is great-enough to create an ignition spark at each spark plug to ignite the fuel-air mixture in each combustion chamber. However, the spark plug wires used to conduct that high voltage from the ignition coil(s) to each spark plug must not only carry the voltage to the spark plug, but it must also shield the wire to suppress RFI signals from being emanated that can potentially interfere with sensitive computer electronics in the car. Solid copper-core wires would act like an array of radio transmitter antennas that would constantly discharge RFI signals throughout the engine compartment and the car -- potentially disrupting sensor signals and computer processing signals. So the design of spark plug wires becomes complex. The wires must both conduct high voltage bursts to the spark plugs to permit proper ignition to occur, but it must also prevent RFI from interfering with the sensitive engine electronics and computer subsystems.

The following link provides a fairly extensive discussion on this subject:

http://www.magnecor.com/magnecor1/truth.htm

[azdave]

My brother had a race-built 70 Super Bee but it was street legal. We always knew when he was coming home because our TV antenna would pick up the ignition interference on the screen long before we heard his loud exhaust. He could be a 1/4 mile away and we would still see the tell-tale lines on the TV screen.