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Discussion Starter · #1 ·
Assuming I go with a Mallory distributor, I still have to choose between a Unilite model and a Magnetic Breakerless model. Both models (at least the two I'm looking at) have the ability to trigger a traditional coil, and do not have to be used with a controller box.

I've done some searches here on VMF, and the camp seems pretty much divided on the reliability of the Unilite models, with some believing they are fragile and some believing they are pretty much fine. I haven't seen any opinions on the Magnetic Breakerless models, though -- it would seem I could sidestep the whole reliability issue by going with this model.

Also, I'm thinking of abandoning vacuum advance, as I don't drive my Mustang enough to warrant the increased fuel economy, and it would be one less piece of clutter in the engine compartment, and one less thing to fail. Are there any other reasons to run vacuum advance?

I'm not dead set on Mallory, but I'm leaning heavily in that direction. All opinions will be welcomed.

Thanks!
 
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I have a Unilite, and have been running it for a couple of years. I have found it to be very reliable and have had no problems. I use a traditional coil on a 351C.
 

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I have been running a unilite since they came out around 1975.I have lost two modules in that time,one of those was my falt.Mallory has an in-line surge protecter to protect the modules now.I have run without a vacum advance for years with no problems.These were in 351c,and 429 s.I like them! My .02 FastE
 

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Unilite is more accurate spark timing wise and magnetic breakerless is more reliable. Most people choose Unilite. You can also use Mallory Dual Points and later upgrade to Unilite if you like. Upgrade is $100 and is done by sending the Dual Points back to Mallory for conversion.
 

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Discussion Starter · #5 ·
Unilite is more accurate spark timing wise and magnetic breakerless is more reliable.
I have seen this mentioned, but wasn't sure how much a magnetic breakerless system would vary. My internet searches so far have turned up nothing that would quantify that difference, although I can believe it exists.

Anyone have some numbers?
 

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if magnetics weren't accurate then why are they used on crank triggers? and did alot of the OEM use them. i think that both are just as good as the other.
 

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I've had a Unilite on my 351C since 1988. Put about 10,000 miles on it since. Had one module fail. Downside is the expense of replacing the module ($95!!!).
 

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Discussion Starter · #8 ·
if magnetics weren't accurate then why are they used on crank triggers?
Dunno... it's just something that's been repeated by various parties when comparing Unilite to magnetic breakerless. I'm thinking that the much larger circumference of a crank trigger system (compared to the shaft of a distributor) probably more than makes up for reduced triggering accuracy with a magnetic system. I'm just guessing, though.
 

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Magnetic systems systems produce a hump shaped waveform caused when the reluctor (metal piece with cog or hump) pass by the pickup. Imagine the electricity in the pickup increasing gradually. At a point along the hill the pickup amplifier triggers and initiates the spark sequence. With changes in temperature this point can vary somewhat. In addition because the input signal is sloped, the exact trigger point is not positive (more like the variation occurring in a points ignition).

OTOH Unilite works by interupting a light beam. A light emitting diode (ultraviolet light) provides a light source. A phototransistor amplifier receives the light. In between the two semiconductors there is a interrupter shutter (like the shutter in a camera). The waveshape produced is more like a square wave with a vertical leading edge to the waveform. Its a cleaner switch. The Unilite's waveform suffers from mechanical jitter of the shutter but relatively no variation from the switch itself.

Bottom line is Unilite run at higher rpms than the Magnetic Breakerless. Both are good technologies and the only time I think it would make a difference is at 8000-up rpm. To answer JohnBears comment...the rpm range where there's a difference is not of concern to street cars where rpms are infrequently above 7000 rpm. It may be a reason why factory engines are rpm limited.
 

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I run a Mallory Dual Points in my '65. Reason is its cheap. I don't drive the car very much and so there is no big advantage to electronic ignition. For the $100 bucks difference in price I can buy lots of sets of points. In addition, changing them once a year isn't a big maintenance task. I spend a lot more time polishing and cleaning the car than I do driving it. Shame eh?
 
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