by firenza2000sl » Sun Apr 07, 2013 1:15 am
Here's my 2 pence worth:
I fitted a Sparkrite electronic ignition to my '67 Viva, and a Tandy electronic ignition to my '72 OHC Firenza. Each was constructed from a kit of components. They used the existing contact breaker. I replaced the ignition coils with standard 12V coils, and bypassed the resistor cable.
Some electronic ignition systems replace the contact breaker with a magnetic or (optical) pickup unit. IMHO the advantage of using the contact breaker is that you can quickly and easily revert to standard coil ignition if anything goes wrong. However, they both worked perfectly for years - and I've still got them, somewhere.
The above systems contained a transistorised generator that applied a high voltage to the coil, supposedly creating a more efficient spark. Cheaper systems were no more than a power transistor acting as a low voltage switch, which prevented sparking across the contact breaker points and eliminated erosion of the contact surfaces. You get this benefit anyway with the high voltage system, plus you get the enhanced spark.
hth,
David