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Duraspark Vs small cap HEI?

6K views 4 replies 5 participants last post by  willowbilly3 
#1 ·
I have a complete '75 Lincoln 460, a new blue strain modual and enough of the orig harness to make a new DS harness.. Would this operate better than a new aftermarket small cap HEI?
 
#3 ·
either way

Both of the systems - the HEI set-up and the Duraspark II have their advantages.
The HEI will definitely operate a "hotter" coil and make more spark "upstairs". It varies the "dwell" (coil charging time) based on AMPS - heating of the grounding transistor. Will go down to 15° near idle - and up to 35° at higher revs - its a nice design.

The Durapsrk II has fixed electronic dwell -about 26° - stays there as the revs go up. It basically duplicates a single point distributor charging the coil. The grounding transistor won't handle the AMPs of a really "hot" coil with low primary resistance. Has a better spark than the HEI at very low revs due to the greater dwell. A really good feature - if you fully wire it in, it monitors the operation of the starter solenoid and retards the spark 6° for starting. If you wire the solenoid detector wire (the white one) to switched (on-off) 12 volts, it will allow manual selection of the 6° retard on command.
 
#4 ·
Matt - do a Google search "Converting a duraspark ignition to HEI". You can easily use the cheaper GM module, even mount it in a gutted Ford module and they work well according to some other folks. Until the current car have always just used the Dura Spark and never had a failure - ever.

Dave W
 
#5 ·
I run a Duraspark distributor with the later Ford high energy coil from an efi and use the GM module. I like that set up real well. Plus it is junkyard cheap. Just remember to put the module on a heat sink. I did mine on a 92 F-250 and just modified the original heat sink that is mounted on the inner fender. I know another guy who modified an aluminum head off a Briggs and Stratton for a cool finned heat sink.
 
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