Corrosion in New Radiators

[scannon]

There is a thread on the Miata.net forum about a fellow with leaks in a nearly new Koyo aluminum radiator. He provided a link to someone called the RadiatorReporter which provided a good explanation of the problem.

 

http://www.radiatorreporter.com/electrol.html

 

I measured the voltage on my Caterham cooling system today and found .24 volts, not good. I have had problems with seeping at the header tank interface. I shut off the master disconnect switch and it dropped to essentially zero.

 

This got me thinking about grounds and I reviewed how I had wired the car during assembly. I found that although I had run the negative battery cable directly to the engine I hadn't provided a heavy duty connection between the battery and the frame of the car.

 

Digging around in my parts shelves yielded a battery cable of the correct length with eyelets on both ends rather than the usual terminal connector. I installed this cable between the Odyssey battery negative terminal and a central ground point on the frame and checked the voltage again and it was down to .027 volts.

 

I rarely drive the car at night but when I have, I've noticed that the headlights would suddenly get brighter or dim a bit as I drove and maybe the lack of a good chassis ground is the problem. I'll take a drive tonight and find out.

 

Update: I drove the car tonight and not only is the self dimming/brightening gone, the headlights are much brighter in both low and high beams. I'll be likely to drive it more at night now as I didn't think the motorcycle headlights I mounted on the care were bright enough to be safe.

 

I had been thinking about adding another ground cable for awhile but never got around to it. Glad the article pushed me to get it done.

Edited September 17, 2009 by scannon
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[powderbrake]

Thanks for the article reference. I will check my voltages, but I think I'm OK as I am a confirmed "Ground Junkie"

 

I have my engine ground tied to the frame with the following. Clean off powdercoat.... Tap hole..... place "Star" type lockwasher under the lug... liberal application of silicone grease to everything to prevent corrosion... tighten down.

 

I also have a forward and aft frame mounted studs for ground points ( keeps the wire runs short to heavy current things like lights and fan), as well as a point on the rear of the engine block for all instrumentation and computer grounds, and finally, a solid ground to the battery and engine block, pictured below. (Flex strap from Auto Zone)