Prestolite Pertronix Ignitor wiring advice

[Tahoedonner]

'79 Scout 2 prestolite distributor w/ vacuum advance.
Couple questions before I seal it all back up.

Air gap is at .213 spec is .200. Good enough?

Does this distributor require the ground wire that came with the pertronix I? I don't think it does but would like to make sure.

I have the distributor apart and am wondering what the advice is on wire placement of the pertronix. I currently have the wires running underneath the plate and out. Somewhat like the stock setup. There seems to be less underneath for the wires to catch on than running them above the plate. Is this how others have routed the wires?



.

thanks,
Mark

 

[Ellie75]

That is how I ran my wiring almost a year ago and haven't had any problems. It's a good company. I just called them and said, "hey, your box arrived. Anything I should know?" and the techsupport walked me through it. Just give them a call if you have questions. Good luck.

 

[Scooter]

I have always used the grounding wire that came in the pertronix kit. Two of my own scouts have prestolite dizzies and had not run the wires like you have. But it looks like it works.

 

[Tahoedonner]

Thanks for the responses. Looks like I'll just keep it the way it is. According to pertronix the air gap is just fine. I am going to use the ground wire as well. Waiting on vac advance canister from IH only that will be here today and this dizzy is perfect again.

 

[sawmiller]

Hi everyone. 1980, sii, petronix in prestolite, points in IH dizzy.
Petronix failed - reason unknown. Bench test numbers (volt/resistance) were present but not in ball park. Another petronix is enroute but in the meantime I found an IH - atlas rebuild. And I added new coil, points, ballast resistor,cap, rotor, wires etc. The resistor was an ru4. Started fine, the moment ballast switched in there was no fire. Stated resistance of ru4 is 1.82 ohm. I measured a bit higher. Then I got an ru6(1.35 ohm) and it appears to be running fine. Voltage as best I could determine about 14 running and at coil b+ about 10 or 11 volts.
What determines a correct coil-ballast-capacitor combinition??
If a person had a variable ballast, what would it be set at to balance performance versus turning the points blue versus a gentle but unwanted sparking across the points? The vehicle is a rolling rusted nightmare but I use it very dependable to plow snow. I put front axle u-joints in it last winter at 10 deg. Just dress for it and have a little patience.

 

[Scoutboy74]

What determines it is a combination of the coil's internal resistance and the amount added by the ballast or resistor wire being utilized. Almost any ignition coil will have a measurable amount of primary resistance when probed across the +/- terminals while no wires are connected. So this must be taken into consideration when attempting to arrive at the proper amount of resistance. I'm assuming this is a v8 engine. With a breaker points distributor and v8, the ideal total resistance is @ 3.2 ohm. You say you purchased a new coil...hopefully a stock replacement, which likely has a primary resistance of @ 1.5 ohm. That figure, along with the first resistor your mentioned would be just about right. But, you need to measure your coil's resistance to find out what it is. We're not worried about voltage measurements so much. Focus on getting the resistance right.
For the pertronix module, no additional ballast is necessary so long as the primary resistance of your ignition coil is 1.5 ohm. If it is a low resistance, aftermarket coil with say .7 ohm resistance, then you will need a ballast of the appropriate amount, in this example .8, for a total of 1.5 ohm. But again, you need to measure your coil so you know that end of the equation in either case. There is no such thing as a variable ballast resistor that I know of. There May be a nominal amount of fluctuation depending on ambient and operational temperature, but this not generally sufficient to create any issues.

 

[Scooter]

thanks for the responses. Looks like I'll just keep it the way it is. According to pertronix the air gap is just fine. I am going to use the ground wire as well. Waiting on vac advance canister from IH only that will be here today and this dizzy is perfect again.

Were you able to keep the pertronix wiring under the plate, like in your photo, when you installed the new vaccum advance canister?

Btw - I forgot to mention in my last reply that I have not had any issues with the air gap once it was all installed. Was all plug and play and forget about it.

 

[Tahoedonner]

were you able to keep the pertronix wiring under the plate, like in your photo, when you installed the new vaccum advance canister?

Btw - I forgot to mention in my last reply that I have not had any issues with the air gap once it was all installed. Was all plug and play and forget about it.

I probably could have run the wires underneath but decided against it once the vac advance went back on.