Best Coil - Coil Relocation ?

[Spurs]

Has anyone any views on what is the best type of coil to use on the TV8 Mk2 ? I have had a few fail and looks like last one is on its way out too. I have lumenition fitted if that makes a difference. Also I have seen kits to move coil from heat of engine, do these help ?

Any info as ever appreciated.

Martin

[V Mad]

If you have had a few coils fail I suggest you test out whether your ballast is fitted and wired correctly. Without the ballast a standard coil will fry and may also damage the Lumenition.

[ChasR]

Is your ballast coil present. What does the coil measure at the terminals with the igntion on?

From my experience I would go with either a Bosch Red coil or the equivalent BERU coil personally. They seem to be very reliable units (both are also wax filled, not oil). Cheap however they are not (about £30-40 IIRC). Moving it away from the Vee does help but it is not a necessity.

Intermotor coils are meant to be ok but on moderns (and in the case of classic car rotor arms) I am not convinced. I would however steer away from a County branded coil. Mine started playing up after the first long run I did in the car.

[Spurs]

Thanks both,

I will check this out. I was told certain coils (Voltage dependant ?) do not need a ballast resistor, not sure if I have one or not ! Is this true or is someone got it wrong ??

Martin

[martin]

Hi Martin, as Chris points out, you may be running 12V through a 6V coil, it has a simple system that puts 12V through it for starting, which drops to 6V when running, if yours is wrongly wired that would explain it, stick with standard, it's all you need in the Stag. Martin.

[Spurs]

Martin, Thanks for explanation. Would I be right that if 12V coil was fitted this would work, I am sure this is what was recommended by my garage ?. Martin

[V Mad]

If you have a 12volt non-ballast type coil (3 ohms) then that will work but your cold starting will not be as good.

Are you sure it is a coil failure? Lumenition can play up. Also if you have a 12 volt coil (non ballast type) and you have it wired via the normal ballast you will not get a good spark.

[Spurs]

Chris,

I will have to check this out. I will also get lumenition checked over too. Hopefully between points offered it will be sorted!

Martin

[wilf]

I wonder why an electronic ignition system that needs no ballast resistor and can be matched to a purpose designedl e.g. MSD 6AL plus "Blaster 2" coil isn't more widely used in these cars?

Utter ignition reliability for me in the Cobra, and that engine was no wishy washy thing.

Far more robust than any lumenition system IMHO.

[ChasR]

As long as the coil is around 1.5Ohms you should be fine (The ballast coils I have seen for sale are around this whereas the non ballast coils are 3.0)). The County coil I got from a Stag specialist was sold as a 12 Volt ballast coil. Both that coil and the Bosch coil on the car have a resistant of around 1.5 Ohms. With the car's on I get 6V at the coil.

Silly question but how long do you leave your car's ignition on for without the engine running? That can significantly reduce a coil's life if left on too long (and kill a battery too).

[stag157.7]

copy and pASTED FROM PETRONIX

MIGHT BE USEFULL

While performing this test, never leave the ignition switch on for more than 30 seconds at a time.

Set your voltmeter to a 15 or 20-volt scale. Attach an 18 or 20 AWG jumper wire from the negative coil terminal to an engine ground. Attach positive (red) lead of your voltmeter to the positive side of the coil, and the negative (black) lead to an engine ground. Turn the ignition switch to the run position. Now read the voltage at the positive coil terminal. Turn the ignition switch off. If the voltage measured is approximately 12 volts, no resistance wire is present. A typical resistance wire will provide 9 - 6 volts.
The next step is to determine the resistance in the primary ignition. Label the wires attached to the coil terminals and note their appropriate location. Make sure that the ignition switch is off and disconnect all wires from the coil. Adjust your meter to the lowest ohm scale. If you are using an analog style meter make sure to zero the needle.
Measure from the negative terminal to the positive terminal. Write your measurement down.
Now the maximum system amperage can be determined, divide your voltage measurement by your coil resistance measurement. This will give you the system current or amperage.
Four and six cylinder engines should not exceed 4 amps. Eight cylinder engines should not exceed 8 amps. If the total amperage in your system is higher than the amount recommended for your application, you should install a ballast resistor.
Example

Voltage 12
Resistance 1.5......................
12 / 1.5 = 8
Total amperage 8