replace old delco remmy 1111 distributor with hei

Pankey, I have thought about doing that, just havn't got around to it.  What is it out of or are you welding 2 distributors together to get one.  DUI(Davis Unified Ignition) make an HEI setup for a small block ford using a FoMoCo bottom and HEI top.  Works real well. 

What will your $300 setup do that a pertronix and good coil can do, for less than half the money? Other than stick out like a sore thumb? 

Garry reality is the petronix is a hall effect switch and has to have a coil with at least 1.5 to 2.3 ohms of resistance to keep from burning it up so does points . So youre feeding a coil with 9 volts instead of a possible 14 volts if equiped with a alternator . The hei has a true magnetic pickup and likes 14 volts so times the coils windings turns by 9 volts and see what youre spark energy is or times youre coil winding turns by 14 volts and see waht youre spark energy is. We ran into alot of troubles last year with the small cap cross arching with the msd 7 box and 50,000 volt pro coil also it was ionizing the air and creating plasma under the cap even with vent holes drilled so the bigger cap with 1 7/8 electrode spacing eliminates alot of troubles when trying to run mid 1980 ignition technology on a 50s era distributor. The hei will give you 80 to 144 mj of spark energy with no msd box just wired to a 12 volt power source.

Edited by mlpankey - 30 Apr 2010 at 9:11am

  O.K. , that was a good explanation.   At some point , an excessive amount of compression will require a hotter spark that a pertronix can provide. The issues you have with ionization and plasma under your cap, I had always thought were perhaps workplace related , too many rads or something......

Chris/CT wrote: MLP, Well described, alway's fun reading your post's! Talked with Steve from CT lately??

 I dont think  weve talked lately. Always time for conversation though.

If you're worrying about ionization under the cap, why go through all that trouble? Why not eliminate the source?

Double-ended ignition coils are available stock and aftermarket now, and can be wired in wasted-spark mode, and crank-triggered, to totally eliminate the distributor altogether.  The double-ended coils used on modern automobiles (my Jeep Cherokee is a good example) are under $40 each, and lay down a staggering spark- even moreso than the external coil used on improved EST-HEI system used on GM engines after 1991.  Back in the age of distributors, the coil's output had to be considered as a limitation, simply because the insulation capacity of the cap's void was insufficient.  I think distributors have essentially been eliminated on modern cars now, but it's certainly not a new idea-  look at Waukesha natural-gas engines from a dozen or two years ago- with Altronic 5 ignition and separate coils for each plug...


Just to clarify- the reason for a ballast resistor on an ignition coil, and on many electric fuel pumps, is so that when you're CRANKING the engine (and applied voltage is low due to the starter motor's draw), that the coil will have more than ample output to touch off the mixture.  Look at the wiring diagrams, you'll see a bypass wire going from starter solenoid direct to coil for this purpose.  Once engine has started, the ballast resistor is inserted in line to prevent the coil from melting down... it is, after all, a 9v coil running on (what is now) 14.2 volts.

And for what it's worth, EVERY transistor-fired ignition control unit, including MOSFET outputs, will impose some sort of voltage-drop and current limitation in the coil primary circuit... because they are semiconductors with P-N junctions.  Silicon PN junction is 0.6v .  This is one thing that ignition points have over transistors- there is either good contact, or poor contact, or no contact.  Running points with good contact imposes essentially no limitation on coil current, hence, higher voltage.



Edited by DaveKamp - 01 May 2010 at 4:08pm