melting coils

P

PHILLIPK

Junior Member
This is regarding my '40 239 original engine. Still a 6V system. Several months ago it would not start and I noticed a foul oder coming from the engine. Took a look and noticed the coil had a brownish, gooey substance oozing from the coil. Replaced the coil with a used one I had. Runs ok but today I noticed a black, gooey substance oozing from the coil. The engine runs but back fires (alot). through the carb. Sounds like gunfire, (which ain't too acceptable right now). What is making my coils melt? Thanks for any help out there.
 
Is there a resistor on the coil? If so, It may have gone bad.

Check the voltage going to the coil. I don't know what it should be, perhaps some one else has the spec.
 
Should show 3 1/2-4 volts at coil. AND you have most likely blown your carb.power valve with all that backfireing. It only takes 1 back fire through the carb to do it. You say its done it multiple times. Smell your dip stick for gas in the oil. ken ct.
 
A resistor won't allow any voltage to the coil if it go's bad and without voltage it won't burn up the coil. It can only fail open not shorted, when open no voltage passes through it. I suspect you left the ignition switch on, this will melt the coil in 10 or 15 minutes. When voltage is applied to the coil if the points are open there is not current draw. When the points are closed one side of the coil has NEG voltage from the battery through the swicth and the other end of the coil primary winding is grounded through the points to the POS side of the battery. In other words both sides of the coil are connected to the battery, the coil now becomes a resistor. The small wire in the coil becomes just like the element in a toaster getting hot and melting the insulation on the wire. This does not occur when the engine is running. The tar in the coil is heated by the heat from the wire. The battery will also run down and all you see is the tar. If there is a battery charger on at the time of a melt down then you may also see the varnish from the wire drip out. This could also cause a fire and is the reason there should be a battery disconnect on all old cars. I don't think a coil will melt even without a resistor when the engine is running, the coil will get hot and the engine will run weak but I doubt it will have a complete melt down. You can sometimes bypass the resistor to get home with a bad coil but you don't want to run it for long periods of time like this. All original Ford coils break down when hot. Skip in Florida rebuilds them with high temperature modern materials which eliminates the coil problems. G.M.
 
G.M.,

What is the primary resistance, in ohms, in Skip's 12V neg coils?

I asked this in another thread, and you did not respond.
 
I never measured one. I'm not really to interested in 12 volts. His coils work on both 6 and if wound for 12 volts works on that also. The point life is long and after 18 years of proven results who cares what the resistance is. If someone wants a differant resistance adjust it with a resistor. G.M.
 
"after 18 years of proven results who cares what the resistance is."

G.M.,

Since you are the apparent spokesman for Skip Haney, I asked for some technical information. You have recommended a specific resistor for Skip's !2 V coil.

The "proven results" I have seen firsthand with Skip's 12V coils are one burned up coil and one exploded. At the time, I called Skip and asked him what resistor should be used, and he said, "I don't know."

I would not buy or recommend any coil without knowing its resistance.

"Who cares?"

I do.

And, I do not want to buy one just to get that information.

Why not supply the requested simple technical information on a product that you are promoting?
 
Ok, thanks. I'm headed down to the shop to smell my dipstick. I wonder if there is a connection between the back firing and the melting coil. Also, I wonder if I should replace the original coil with the adapter and the remote coil?
I'll keep you posted, thanks again.
Phil
 
Back firing can be lean mixture ,bad condenser , Air leak in manifold .Going by the resistance in Skips coils you could run a 12 volt modern Ba-lace ,
 
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