• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Lucas Sport coil question

Share this page

T

Tinster

Guest
Guest
Offline
Gotta a question about the Lucas sport ignition coil.

I'm building a traveling repair kit to attempt a
70 mile R/T journey in Crypty. Crypty eats ignition
coils so I ordered a third spare coil to carry with me.
This time I ordered a Lucas Sport coil.

Now I'm wondering if maybe I should install this new
coil as my primary coil and not keep it for a breakdown
replacement.

My question: I have Jeff's rebuilt dizzy with the Petronix
electronic ignition. I installed the GM alternator
conversion and the Dan Master Power Block entire car rewire
system.

If I install the Sport coil do I need to adjust the spark plug gaps? install different plugs? reset the timing?
mess with the Petronix system?

I'm not real sure what "Sport" coil means.

Thanks

dale
 
The sports coil puts out a slightly higher voltage. But it will only do this if the gap on the plugs is increased. You probably don't want to know the physics behind that! If you swap it in without adjusting the gaps, you will get the same spark you have now.
The disadvantage of using a higher voltage is that the extra voltage is more likely to cause the spark to jump somewhere that you don't want it like burning a line across the dist. cap.
Don't they sell coils on the island? they are fairly generic.
Yisrael
 
Yisrael,

Yes I can purchase coils at Western Auto.
They seem to burn out rather quickly in my car;
which is why I decided to carry three spares
in my trunk.

I purchased the Lucas brand as a spare thinking
it might be better for the car. Now I see I should
not have purchased it as it might do more harm
than good.

Anyone need a Lucas Sport coil, in the box unopened?
I've got one.

d
 
hey dale, if you decide to get rid of the sport coil let me know, i was just about to do a tune up on my tr6 and get one in a week or so. let me know how much you would want for it. thanks
Randy
 
How much would you increase the gap to compensate for the sport coil?
 
I would solve the ignition problem and not have to worry about carrying spares.
 
Dale,

The coil should last a long, long time. You might be using a coil meant for a 12 volt system with a ballast resister and if your car does not have the resister, or if the resister is bad, it would burn the coil out.

The ballast resister system would start the car on 12 volts and when the starter solenoid disengages (starter stops) it would drop to 4 - 6 volts for running.
 
Dale,
I fitted a sports coil to my TR3 years ago and didn't know about opening up the plug gaps. The car has been running fine for at least 10 years on it. I would have thought that you should have no problems with it.
Nick
 
Dale
Spark is controlled by two things, input voltage and spark plug gaps. First off, if your system requires a resistor, then it will control input voltage to about 9.5 volts. This is measured at the positive post of the coil with the engine running. If this is at that level, then only plug gap can change voltage. In other words, the coil is only reactionary.
It will not cause a problem if the rest of the system is ok. I would make sure you have the correct voltage coming to the coil, and as far as the super coil goes, use it as it won't hurt crypty
Dave
 
I agree you may be having an issue with your ballast resistor. When was the last time you replaced your points, resistor, and leads? No car should eat coils like you are describing. I would start with a general freshening up of the distributor itself....cheap to do and good preventive medicine in its own right.

As an aside, several months ago I put a Lucas Sport coil on my 73 midget and opened the plug gaps a hair...no problems to speak of and it runs great.
 
Nathan, if you read his original post you will see he has a freshly rebuilt dizzy by the dizzy guru and is running the Petronix ei.I don't think he has to run a ballast with his coil with the Masters wiring panel. I don't know Dale.
 
Tinster said:
Yisrael,

Yes I can purchase coils at Western Auto.
They seem to burn out rather quickly in my car;
which is why I decided to carry three spares
in my trunk.

I purchased the Lucas brand as a spare thinking
it might be better for the car. Now I see I should
not have purchased it as it might do more harm
than good.

Anyone need a Lucas Sport coil, in the box unopened?
I've got one.

d
Click to expand...

---- /bcforum/images/%%GRAEMLIN_URL%%/savewave.gif

NO NO Tinster do not part with the Lucas coil. Installing the Lucas coil with the Pertronix is a plus. Put the Lucas in before the trip in accordance with the instructions provided. Put the WA unit in the bot as a spare. Now set your spark plug gap ~ 0.008" above the stock setting. Adjusting the point gap has nothing to with the output from the coil, other than we want to take advantage of its higher output. The out put from the sport coil is about twice that of a stock Lucas coil. Consequently,it is possible to improve combustion in the cylinder by getting a larger spark via the wider plug gap when this coil is used.---Fwiw---Keoke.
 
14dna, In the automobile system the voltage generated in the secondary system of the ignition circuit is dependant on the switching time of the coil by the interrupter given that the voltage applied to the coils primary is of the same amplitude. Therefore adding the pertronix unit in place of the original points will increase the secondary voltage in the system significantly because the switching time of the solid state switch[Pertronix] is so much faster than that of a set of points. Adding the Lucas coil which has a higher output voltage than standard coils will increase the secondary voltage even more, which allows a wider spark plug gap to be used.--Regards--Keoke
 
If you are purchasing coils at western auto, they are probably of the type that needs a ballast resistor. If you don't have that, the coils will fail regularly. This sounds likely as most all vehicles since the early 70's have used resistors*.

Put the Sports coil on and your problems are probably solved, as that coil is meant for 12V supply.

Leave your plug gaps as they are... or increase them slightly for higher voltage.

* Some people like at Ford would include the resistor as a resistor-wire within the wiring harness and therefore invisible to the average person.
 
Ok Dale before panic and to many opinions sets in
As has been pointed out
1. your Western auto coil probably needs a resistor. Lack of a resistor will explain why it is burning out so frequently.
2. the electronic ignition will raise final voltage. This is good.
But to much of a good thing is not always good. To high a voltage will burn out the dist cap / rotor or find any damage in the cables insulation.
So. Put in the Lucas sports coil, but leave the spark gap as is. That way you don't risk overdoing it.
Now go downshift to 3rd and make lots of fun noise!
Yisrael
 
As others have said, the reason you're burning out coils is because you are putting in a coil that requires a ballast resistor. Dan Masters' wiring diagram shows no ballast resistor in the circuit. To be sure you are putting in the correct coil, you will have to measure the resitance between the two small terminals on the coil. If it's still installed in the car, you will have to remove at least one of the wires. If the coil measures about 3.1 - 3.6 ohms, it is internally ballasted and is the one you want to use. If it measures about half that (1.5 - 1.8 ohms), then you have to add a ballast resistor, or get the right coil.

Measure the resistance on the Lucas Sport Coil before you just throw it in to make sure it will fit your application.
 
Wow, I didn't know Western Auto was still around. Can you still get Wizard tools there? What is the gun brand, Western Field?

Wonder if there are any Joe, The Motorist's Friends around anymore?
 
Art et al:

I spoke with Dan Masters about the coil and he
instructed me to purchase non-ballasted coils.
That is what I am using.

Come to think of it, I have not burned up any coils
in almost 200 miles of short hops driving.

I am loading up Ctypty with spare parts for an attempt
at a record breaking 70 mile R/T journey.

Maybe it luck of the draw that 3 burned up so quickly?

d
 
Tinster said:
Art et al:

I spoke with Dan Masters about the coil and he
instructed me to purchase non-ballasted coils.
That is what I am using.
Click to expand...

Did he mean a coil that doesn't require a ballast?? One that is ballasted internally?? Perhaps there is a mis-understanding as to the correct nomenclature. I guess a non-ballasted coil is one that doesn't require a ballast resistor.
 
Back
Top