The Stovebolt Site Forums The Shop Area The Electrical Bay 6 volt Coil (30.000 volt)

Hi Guy's, where can I buy a HD 6 volt Coil (30.000 volt). The reason that I need one is that I just got a Dual Point Mallory unit and the directions tell me it needs a 6 volt 30.000 volt coil to work properly. Dutch

pertronics coils are availiable in some places

Go to your friendly NAPA store and get an IC7 it will be a 40,00 volt coil and will work just peaches...and you will no longer need the external ballast resistor another good benefit . Thanks Randy

6 volt coils don't need a ballast resistor.In reality,there's no difference between a 6 volt coil and 12 volt coil requiring a resistor for a points ignition.Both will have an ohm reading between the two primary terminals of 1.2-1.5 ohms.I have checked this out many times on GM coils.
And again,a clean spark plug needs only about 3000-5000 volts to fire in an engine with somewhat rich carburation and low compression(like old truck engines)The original type caps and typical 7mm plug wires don't have the dielectric properties to cope with 40,000 volts.High voltage ignitions are needed in emissions engines running lean mixtures and modified high compression engines.The old 60's Muscle cars manged just fine in their day on stock coils and wimpy 7 mm carbon wires.

The reason that I need one is that I just got a Dual Point Mallory unit and the directions tell me it needs a 6 volt 30.000 volt coil to work properly. Dutch

I'll bet ya 10 bucks a 12 dollar coil from Autozone will work as well in your situation as any high buck coil.Spend the leftover money on a set of of NGK XR5 spark plugs,about $1.80 each and a set of quality plug wires,low impedence spiral wound type,about 40 bucks

Speedway motors has some NOS 6V performance coils (maybe Mallory?). I have tested several performance and stock coils with points ignition and found no real difference. Buy a standard coil.

Ohms and voltage are two completly different things...and the ballast resistor is used to control the voltage (actually reduce) the voltage to extend the life of the contact points. So you defenitely DO NEED a ballast resistor in the ignition circuit, either the internal kind which works best ot the original external type.
Unless you are into walking and want to change ignition points about every 100 miles....

As for the cheap coils there is a huge difference and you do get what you pay for...many of the cheap coils use aluminum windings (instead of copper) which creates high resistance when the coil get hot which translates to a weak spark which you will experience as a truck that will not start when the engine is hot. Battery is up engine cranks fine but engine will not start.

Next up the cheaper coils have a lot of trouble with carbon tracking up where the ignition coil wire attaches to the top of the tower. When that happens you experience a miss that you often blame on the points or condensor. You end up with an annoying miss from the ignition that you can never seem to find. Think of it as an electrical drip. it is often hidden until you open the hood up at night and see the electrical drip for yourself.

I have fixed hundreds of mallory ignitions over the years by installing the IC7 ignition coils with the internal ballast resistors. Dual points will make the problems associated with a cheap coil even more apparent.

So take it from one who has been there and done that... buy a good quality coil and be done with it. Your truck will thank you!!

Randy

The man asked for a 6 volt coil,6 volt GM systems don't use a ballast resistor in the ignition primary.
The price of a coil may not reflect the internal construction,I bought a 12 dollar made in Mexico coil when the expensive new Pertronix coil failed on a road trip.The 12 dollar coil said on the box it was heavy duty with all copper construction,I didn't cut it open,but I suppose I'll take their word for it.This coil is on a modified 302 GMC with high compression and a dual point dist,runs smooth from idle to redline.It's a 12 volt system,so it's got a resistor.One problem with internal resistor 12 volt coils,is there is no way to bypass the resistence when starting.On a high compression engine,the starter may draw enough current to lower the available voltage to the coil and make hot starting difficult with a bypass.I have personally experienced this problem on my 302 engine.When I switched to the cheap coil and used an external ballast with a bypass,hot starting was instant.With the Pertronix,hot starts were difficult until the engine cooled down.
You do get what you pay for,and sometimes you pay more for the same thing.Price is no guarantee of high quality,as I found out.

Thanks for the expert answers and suggestions. Dutch52