8n Front Mount Distributor, 12 volt coil.

Eamon

Once more...frontmount 12 volt coils used to have a molded warning tag alluding to 13 volts MAX. Believe it... The problem arises because the 12 volt alternator will generally output about 14.7 volts to properly charge a 12 volt battery. This 14 volts will cause excess current to flow in the 12 volt frontmount coil and will melt the insulative tar and short out the coil windings and ... oops... no sparkies.

There used to be included in the box with the new 12 volt frontmount coil, a instruction sheet that told the user what "value" resistance to use to prevent the above described overcurrent effect. Since my 8N is an eazy starting 6 volt sidemount, I never got the "resistance value" for a 12 volt frontmount conversion.

So to answer your question, yes, you do need some sort of current limiting resistor inline to your new 12 volt frontmount ignition coil. Unfortuneately, the OEM 6 volt "ballast resistor" is not the right value.

I can make a guess at about 0.5 ohms and 25 watts, but I really don't know for certain. Here is a "clue" for you. The proper value resistance (its not too critical) will give about 10 volts at the coil terminal (9 min, 11 max) with the ignition points closed without the engine running. And battery voltage with the ignition points open.

Anyother voltages than what I've just "quoted" are going to give you "problems". HTH..... ...Dell

If you measured approx 10 volts (9-11) with the points closed and engine not running (batt 12.6v as only source of power), then with the engine running (power provided by alternator - 14.7v) the voltage to the coil would be approx 12 volts (11-13)?

Jim

Howsomever, the frontmount ignition coil is kinda squareish and sits on top of the frontmount distributor and is not as robust as we'd like so we have to handle with kid gloves by "limiting the current" thru them with somesort of external resistance. Its an "Ohms Law" kind of thing..... .Dell

JMHO