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Old 12-04-2012, 07:11 AM   #2
StephenB
G(/)S ... what else!
 
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Joined: Aug 2005
Location: Ontario
Oddometer: 2,044
There is more to it than Ohm'sche resistance. Your 2 x 0.7 or 0.66 limits your current to the coils, so with lower resistance comes higher current and eventually higher coil charge using the same dwell time. So I would agree that from that perspective there should be enough margin to run the 6V/0.66 Ohm coils. Don't forget though, that with heat the resistance decreases and at 3000rpm + your voltage is more about 13V than 12V. So its more like 10A current.

Now as to the coil inductance: the coils discharge upon shortening the primary side to ground and that creates a strong temporary force field which in turn creates a high voltage at the spark plugs and a back EMF. The force is dependent on the inductance and charge of your coil and that could be a limiting factor. That high voltage on the output (8KV+) does create a higher voltage at the primary side as well which has the potential of damaging your ignition module when running an electronic ignition or arcing of points when running a Kettering ignition.

I have tried it with different coils, but never long enough to see any long term problem.

(Disclaimer: due to my mental state I can not be made responsible for any damage resulting from using the provided information)
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Stephen Bottcher
Ontario, Canada

'72 R75/5 The Blues

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StephenB screwed with this post 12-04-2012 at 05:37 PM
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