OK, I put a Pertronix Ignitor and a 40,000 volt flamethrower coil on my stock 289 4bbl with an auto transmission. This is in my 65 GT. What plugs should I add with this set up and at what gap? I've heard that the gap on the plugs can be opened up using the pertronixs ignition but how much? Thanks for any input.

 

Hi,
It's a wild **** guess! I'm running .045 with a Pertronix and CD box (Jacobs). This seems t work well for me. It may not work for you, as every engine is unique in their build and settings.
Do keep in mind, when you do start to increase those gaps, you'll be adding additional load (stress) on the primary ignition (cap terminals, plug wires etc.). In your case, I would probably not exceed .040, though.
good Luck!

 

I have the Mallory 50,000 volt coil and the installation sheet tells me to open the gap to .042 but after talking to their tech department they suggested I go to .045 but ensure that all your centrifical timing is in by 3,000 RPM and not to advance greater than 36 degrees.

 

Hi,
That advice seems reasonable, especially, since I'm running the same basic settings. Although my initial is 16 deg with a total of 39, or so. But, just keep in mind, as I mentioned previously, insure your wires are in good shape.
Happy Trails....

 

I just ran into another snag. On the coil installation it says to replace the pink resistor wire to the new coil with a regular wire. The snag is that I have a stock Rally Pac tachometer that is wired in series on the resistor wire. If I run a regular wire I'm afraid it would burn up my tach. What options do I have. I woud like to keep the original tach.
Thanks for any input,
Steve

 

Hi,
The resistor wire is there to reduce the voltage to those coils needing an external resistance during the run mode. Apparently, your new coil is internally resisted. This prevents the overheating of the coil in the "run" mode and does not affect the tach, as the coil is fed 6-8Vs. Coils are provided 12Vs at start-up, only, to maximize spark capability.
So, you could bypass the resistor side (wire) to the coil with a full time 12vs?

 

Just to clarify the statement:
The pink wire takes the voltage down. Bypassing it sends 12 v to the coil all the time so the Rally-Pak tach will get 12v all the time. I don't know the effects of that full time voltage to the tach but suspect it will damage it after a while.

 

Hi,
"I just ran into another snag. On the coil installation it says to replace the pink resistor wire to the new coil with a regular wire." This comment, was what I was referring to when I mentioned running a by-pass wire from the ign. sw.
If you look at your wiring schematic, your tach is getting 12Vs now from the BAT term at the ign. sw. The other side runs through the resistor wire and on to the coil (OEM). When the ign. sw. is released after the start, the run ckt. (encompassing the Tach) now reduces that previous 12Vs to 6-8 through the resistor to the factory coil. Theoretically, I suppose could leave that resistor ckt. in place and add a dedicated 12Vs to the new coil. In the event the dedicated 12V lead is damaged in some way to render it useless, at least, you have a "limp home" ckt in place...?
Hope this adds additional clarification.

 

I thought about this but was unsure about the tach. Would this set up still allow the tach to work?
I am currently awaiting a reply from Pertronix in regards to this problem. I will let you all know what their answer is.

 

Yeah, please let us know. As I read the circuit schermatic from Ford, the rally pac tach is put in series between the ign switch and the pink wire that goes to the coil's B + terminal.