Coil Wire Length

[John R. Graves]

I'm going to be doing Bherder's GM HEI conversion. I'll be using a E-core coil and I'm thinking of placing it on the inner fender behind my washer fluid bottle. My question is: Is there a maximum length that the coil wire should not exceed or that may lower voltage too much? ~John

[bherder]

Mmmm ... good question. I dunno. I'd guess someone here does know..
I do know that, wherever possible, to keep you wire lengths as short as possible

[moe7404]

moe in wichita ks more important than length is the resistance, find an older service manual the ignition section should show the limits of resistance. i am going to guess no more than 7-8k ohmns just a guess . daa i just saw a 1967 chrysler manual next to me. it says if coil wire has more than 15000 ohms replace it, plug wires are more than 25000 ohms replace it. now remember they are talking about oem wires, if you are using aftermarket wires these numbers will be different. i think those numbers are a bit high.

[3834B]

wherever possible, to keep you wire lengths as short as possible

Yep. Plain and simple. If one has to 18" would be my maximum allowable. I would also try to get that thing on the firewall if possible. Way better environment.

Moe, your numbers on resistance are right where they should be.

[John R. Graves]

Thanks for the input, all. I'll find a place on the firewall, I was worried about a long run of wire and increased resistance. ~John

[moe7404]

moe in wichita ks what i used to do is make the plug wires out of solid core wire, then go to a shop that sells two way radios and get the coil wire but cant remember what resistance it was. also if you have a dodge with a dist cap, it most likely has a vent if so get out the j-b weld and plug the vent. when it gets wet youl be glad the water is on the out side of the cap. been doing it for years, no trouble