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Discussion Starter #1
I am looking at picking up a mallory 47 series vacum advance (with leway to adjust mechanical advance) for my stroked 390 FE build. Thought, comments, experiences? I have a chance to get one ..less a cap and rotor.. installed but never started... for about $125-$150.
 

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They are very good, but very sensitive to coil voltage

If you have more than about 11V at the coil positive terminal after the battery charges post start-up, it will eventually leave you walking.

That means if you just slap it in there with Ford wiring, you will eventually walk, because as the battery charges, the coil positive post voltage starts to climb. It stays lower than alternator voltage but can climb as high as 13.5V

However, if you wire the Unilite correctly and have the correct resistance feeding the pos side of the coil, they work superbly. I ran one on my Mustang for 8 years without a hiccup after I was taught about the voltage concerns. The ONLY reason it isn't there now is because I converted to EFI which uses a computer controlled TFI distributor

Guys tend to think that the LED fails due to power surge to the light itself, that RARELY if ever happens. Mallory says the light can take 14+ volts to the red wire.

What happens is that with too much voltage to the coil, as the distributor triggers, it can back feed the module.

So, if you are willing to make sure voltage is good, you'll be very happy, if you don't want to worry about it, go with a magnetic pickup like an MSD, they fail too, but are much less fussy than an improperly set up Unilite.
 

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So in your opinion.. $150 or less for one minus the cap and rotor (which is around$35 ) that has been installed in an engine but never fired up is good?

Thank you for your input. It is greatly apprecciated.

Tommy
 

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I have one with the Hifire box and huge black blaster coil (or whatever they're called) and it work great. Unfortunately no vacuum advance. It was all on the car when I got it.

That price is right in range with what they go for used, so a good deal IMO.
 

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So in your opinion.. $150 or less for one minus the cap and rotor (which is around$35 ) that has been installed in an engine but never fired up is good?

Thank you for your input. It is greatly apprecciated.

Tommy
It doesn't sound like a bad price, I sold my used one with a spare module and cap for 175.00

BTW, if you use it to trigger an MSD or Mallory CD box, it will nearly NEVER fail, because at that point its only triggering a 5V signal out of the box, not bleedover from the coil
 

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Discussion Starter #6
I lost my chance. Bid too late and lost it on Eb...sucks.. But other options will come up. I may just pitch for a new one.. No telling what problems someone else has had with some things..sometimes I guess it is better to just start from scratch.
 
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