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As I understand it, standard points ignition systems typically use a lower voltage coil and electronic ignition systems use higher voltage coils.

Could a points ignition system be upgraded with a high voltage coil? If so, what would the voltage limit be? And, would a ballast resistor be required? Has anyone made this change?

I seem to recall that a ballast resistor helps generate a higher voltage at start up - probably for cold start / emissions reductions reasons. Is this correct, or does it serve other purposes?

Alfa - Sport
 

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Actually, the ballast resistor is wired to generate LOWER voltage for a running engine, and full power for starting. It's in series with the coil power wire so that the voltage drop across the resistor is about 6 volts, leaving only 6 volts for the coil. It's power side comes from the "run" position on the ignition switch. The "start" position has a wire directly to the coil so that starting is at full voltage.

This has the effect of reducing arcing across the points to extend their lifetime, but it also cuts the spark voltage.

Replacing the points in the distributor with one of the electronic or optical triggers means you can do away with the ballast resistor altogether. Also, I ran a race car with no ballast for years with a Bosch points set-up - wear of the points was the least of my problems, and fewer wires made for better reliability. ;)

If you are going to use a HP coil, you are defeating your purpose to keep the ballast resistor at all.

One of the multi-spark ignitions with a no-points trigger will do very well. Use solid copper wire for the ignition wires ( though the fancy specs of high temp silicone covers does not matter for alfa 4's - the wires are no where near the exhaust manifold). Copper ignition wires do not break internally with repeated removal like the carbon-core or magna core wires do. They do leave pretty large EMI pulses which screws up your radio - but mostly in AM bands.

Besides, with the top down, who cares what's on the radio. Or you could get those fancy and costly Bosch wires that have resistors built into the plug connectors and metal shields over the plugs themselves....

Robert
 

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Robert,

I've always used copper core wires but MSD does spec their own wires for their ignitions advising against anything else. Planning on using an MSD. Any thoughts on the wires?
 

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I have an older (non-MSD brand) multi-spark-discharge ignition that works fine with stranded copper ignition wires. I'd guess the MSD recommendation is to avoid the radio interference.

What was important to me was to avoid the fiberglass-impregnated carbon core wires. Even the Magnacore wires are made this way, and add a fine wire coiled around the core. The problem here is that for racing, of just frequent garage fiddling, pulling a wire risks splitting the carbon core, which will immediately affect the spark.

The only place it really matters if when you run your engine at high rpm. Then the damaged wire can very sightly delay the timing of one or more sparks. The Alfa's are already vulnerable to pinging from today's low emission fuel, which is hard to hear at high rpm...

If you are always careful to pull the wires by the rubber boot over the plug and not the wire, and never pull the wire at the cap end at all, any wire set will do. I'm really careful and do it sometimes anyway.

Robert
 

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Oh, and BTW -

Stranded copper wires are cheap, and can be made up yourself - just buy some crimp on ends and boots. I even solder the wire to the ends.

Cheap and better performance are a winner for me....

Robert
 
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