Lotus Elan and Lotus Elan Plus 2 Forums

I am going to fit an Aldon/Pertronix igniter having had excellent experience on two previous cars, however I see they now make igniter 11 which controls dwell. Has anyone got experience with igniter 11 and is it worth the additional cost?

The basic Ignitor has no internal self-protections. If you reverse the polarity for even an instant, it will fry. If you leave the ignition on for a long time without the engine running, or if you install a modern high voltage (also high current) ignition coil, it will over-heat and fry.

The Ignitor II protects itself from reverse polarity, and will simply shut itself off if it over heats... turning back on after it cools down. And the Ignitor II actually prefers the modern coils with low internal resistance (low Re... R sub-e) that draw more current to put out more voltage. And yeah, then there's that dwell thing it does...

The down side is that the Ignitor II is larger than the Ignitor, and doesn't fit in the Twin Cam's small, OEM Lucas distributor. Jeff Robinson (retired from JAE), once told me he installed an Ignitor II in his Elan, but doing so required cutting and carving the cast, 'potted' epoxy housing down to fit. He aslo mentioned that the first stroke of a file voids any warranty; so you can make it fit, but at a price. And if you cut too deep in the wrong spot, and damage something inside, then you're on your own... the warranty won't 'fix' it so you can try it again.

That part about frying the amp by leaving the switch on has to do with duty cycle. Both the breaker points and an electric amp (ie, a solid state electronic on-off switch) turn the coil's charging circuit On-Off. It charges when On, and fires when switched Off. How long it's On is the duty cycle. The spinning engine/ distributor is a roulette wheel. If it stops with the breaker points or amp in the ON position, and then you turn the ignition switch On without starting the engine (ie, working on the electrical system), then power runs through the points/ amp full time and can burn the points/ fry the amp (ie, 100% duty cycle). Points 'burn', an Ignitor fries, and Ignitor II switches itself off. 'Burning' and frying are both permanent, destructive failures.

The Aldon/ Pertronix Ignitor is a simple "points replacer" electronic ignition... no smarter, and no more robust than old mechanical breaker points. The Ignitor should be used with original "points" type ignition coils... nothing hotter, and not with modern low Re high performance coils. You might get by with an old-school Lucas Sport Coil (gold), which was 'hot' by old breaker points' definition, but was definitely not hot in terms of Pertronix "Flamethrower"/ 45,000 volts.

Regards,
Tim Engel