Just thinking: Wire material choices

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The Artist formerly known as Turbo84
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Clinging to my guns and religion in KCMO.
Right now I'm just doing some brain exercises, but I'm also looking for opinions on wiring material (copper and aluminum). I'm running out of ideas on weight reduction for the car, and an (admittedly odd) idea popped into my head. I was just wondering what the pros and cons are of running some large aluminum wire in place of the copper in the battery cables.
According to what I could find on the web, aluminum has 61% of the conductivity of copper, but only 30% of the weight. So, doing the math, I would need 1/.61 = 1.64 times (cross sectional area) as much aluminum to preserve the same electrical conductivity, and then multiplying by the weight ratio: 1.64 x .30 = .49, or about half the weight of the copper cable.

Now I know (or at least I'm assuming) that the stock cables don't weigh all that much, but in the (future) event that I actually got caught up with stuff on the '69 and was looking for something to do, what would be the reasons for not doing something like this?

Wire flexibility, crimping/soldering issues, oxidation, terminal sizing avalability, cost, etc??

thanks,
Mike
 
We use a general formula of 70% conductence of copper. Copper is good for 1000 amperes per 1" square cross sectional area, and alum is rated at 700Amperes per 1" sq xsec. Most alum buss is tin plated to aid in conductivity, and take advantage of the skin effect.
Now, for the question at hand.
Aluminum wire is used extensively by utilities here underground for 600v and below service entrances, and even overhead triplex. The wire is buffed, greased up with noalox paste, and crimped using up to 6 tons pressure to crimp on a tin plated aluminum lug, essentially bonding a lug to the wire, and eliminates all air contact as well.
This virtually eliminates oxidation and cold flow issues.
In private sector use, I only see it used in #6 or larger sizes, where it is buffed, coated with nolox, and connected with alum rated connectors or tin plated lugs. This usage is also increasingly rare.
#8 lugs and smaller are virtually nonexistent anymore. They have a high failure rate, and are susceptible to oxidation, cold flow, and low tensile strength. Commercially available lugs at this time would be limited to a #10 set screw lug, with no known crimp type AL/CU connectors available.
It "could" be done with extreme attention to detail, but, it would prove to be high maintenence, and unreliable at best. I highly discourage the thought, and would seek other methods.
 
I shipped a complete wiring harness for the RX Snake. It weighed 40lbs I think.
 
Check your existing cables, they should already be copper clad alum., pretty light.


alumcable.jpg


CoppercladAlum.jpg
 
Check your existing cables, they should already be copper clad alum., pretty light.

alumcable.jpg



Well, that's amusing. Perhaps my question wasn't that far out in left field. I'll doublecheck my cables (I don't remember seeing anything out of the ordinary when previously messing with the cables), but this sure looks like something newer (technology wise) than what would be on my '69.

Thanks for the info!
 
Check your existing cables, they should already be copper clad alum., pretty light.

alumcable.jpg



Well, that's amusing. Perhaps my question wasn't that far out in left field. I'll doublecheck my cables (I don't remember seeing anything out of the ordinary when previously messing with the cables), but this sure looks like something newer (technology wise) than what would be on my '69.

Thanks for the info!

Yes and no. They are crap, and go bad without any visible signs of failure. The crimp fails inside, and the resistence shoots to the moon.
 
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