Spark Plug Wires

[Musicman]

Hello again -

To all you TR-6 people out there, what wires are you using and why? I'm running with a stock distributor with points/condenser.

On a side note - concerning the condenser - what exactly does it do and how would you know if one was bad?

Thanks,

Dave

 

[TR3driver]

The primary function of the condenser is to slow the voltage rise across the points just after they open, and thus reduce sparking at the points.

If it fails completely, the engine won't run. If it fails partially, you can usually see a buildup of metal on one side of the points.

Unfortunately they no longer make the wires I'm using on my TR3.

 

[dklawson]

On our Triumphs I am running Bosch plug wires because they were easy to get and are a "name brand". On the Mini I am running a set of Accel 8mm wires I made up from a "kit" for a Chevy V8.

I made the wires for the Mini because I am running a different dizzy and the stock wire lengths were not quite right. Making the wires from the V8 kit allowed me to make a very neatly dressed package. The Accel wires have been quite good. They have built in noise suppression but they are not strictly a carbon fiber type. I have enough "left over" material to make at least one more 4 cylinder set of wires if not two.

 

[6969ronin6969]

Not Accel or Bosch, but I did pretty much the same and got a V8 kit from NAPA, Belden, i think is the brand. And they work great. You can cut to any length you need which may add some options to routing depending on your preferences.

Eric

 

[tdskip]

David - going with a Pertronix or similar will make much more of a difference than spark plug wires. If you haven't considered it perhaps it is worth checking out. Also worth talking to Jeff at Advanced Distributors about ignition ideas. Great guy, super knowledgeable, but be aware you'll probably end up doing business with him. Grin.

Tell him Tom and about 100 other guys here sent you.

 

[poolboy]

Last time I checked Advanced Distributors was selling Bosch Premium wires.
Anyway that's what I use.

 

[foxtrapper]

The ignition is a nice LCR circuit. The condenser is the C in that. It's part of the tuning of the circuit.

When the points close, the circuit discharges to ground, collapsing the magnetic field and creating a spark at the plug. Well and good. But, the collapsing field goes right on past dead, out to the other side (boinging like a spring). In fact it will keep on bouncing back and forth for quite a few microseconds before gradually dampening down. That's not good, as you want the circuit stable before you cycle the points again for the next spark.

Enter the capaciter (condenser). It works in an electrical circuit just like a shock absorber works on a suspension, damping the suspension spring oscellations. The capaciter dampens the electrical circuits oscellations.

As a result of all this, the points will not have a spark go across them when they open. Many people mistakenly conclude that protecting the points from arcing is the reason for the capaciter, but as you can now see, that is not the case.

 

[TR3driver]

When the points are closed, a magnetic field is built up in the core of the coil. When the points open, the field collapses, and induces a sharp voltage rise in all of the windings, both primary and secondary. That means the voltage across the points tries to shoot up to several hundred volts. Not a problem if they are fully open, but they actually open pretty slowly (especially when just cranking the engine). Without the condenser, the rising voltage jumps the tiny gap at the points, and dissipates most of the energy stored in the coil, leaving none to jump the plug gap.

Oh, and the voltage still rings after the spark is over. Doesn't matter at all, because it will stop when the points close and short out any ringing still going on.

 

[Twosheds]

The official answer that the FAA wants to hear is, "Aids in the collapse of the magnetic field and helps keep the points from sparking."

I guess the magnetic field collapses quicker (to make a stronger spark) if it charges the condenser rather than jumping across the open points.

 

[Brinkerhoff]

I never really understood the condensors function until now. I've had a few fail with different symptoms: hard to start and backfiring through the carbs. They are too cheap to not replace or carry a spare.

 

[Brosky]

I use Magnecor wires on mine. I have a set that is three years old, which has never given me a problem, but I guess some of the later sets have issues, from what's been said here and on other forums.