Recommended Spark plug gap

[vping]

I'm going to run NGK BPR6RGP #7084 in the '74B. Pertronix LU-142A. Napa guy says to gap at .025" (which I used in the GT) What should I use and does it matter with Pertronix?

 

[Steve_S]

I'd run .032" as a start. .028 would be a minimum.

 

[DrEntropy]

Agreed. The 0.028" wouild serve for a 'conventional' iggy system, the whizz-bang electronic stuff you've got will jump 0.032" with pleasure.

 

[Nunyas]

I triple the motion! I would run 0.032" with one-o-dem electrogizmo iggies... I run a Crane XR700 and NGK plgus set to 0.032".

 

[vping]

So is my .025" in the GT too close?

 

[Nunyas]

Pertronix is an electronic iggie, if i'm not mistaken. I'd bump that up to the 0.028 - 0.030

 

[DrEntropy]

Is it rigged with a Crane or other "embellished" iggy? If it's points, 0.028" is right. If it's an Opus or Pertronics or Crane, etc. it should be the wider gap.

 

[vping]

GT is bone stock. The roady is the one i'm going to start souping (sp) up.

 

[DrEntropy]

Points dizzy would have a 0.028" gap for plugs then.

 

[vping]

Running .025" in the GT would make it run how then or should I say running a wider gap would do what & running a smaller gap would do what in either case? Sorry for the rookie question.

 

[Steve_S]

.025 is fine for a stock '67. Early cars ran a smaller gap than later ones. With modern ignition components you can easily run .028. With a sport coil you can push it even further, although the performance difference between the various gaps will not be large.

 

[vping]

So what kind of coil should I have running the Pertronix? I have a few here but I believe they are all stock. The one currently in the car "looks" weird and I think I should replace it. GT has a lucas gold sport coil in it.

You might remember this. Note the broken porecelain thingy in the corner. This is in the roady.

 

[Steve_S]

What's up with the tupperware toothbrush holder? LOL! Ok, take that thing out and put something better in there. Pertronix sells a coil to match their EI modules, or you can use a Lucas Sport. I'd go ahead and change it to ensure the EI unit is getting the proper voltage. Points don't care but electronics can be damaged by too little juice.

 

[vping]

I think I might order it. It's a flame thrower Moss #143-265.

 

[aeronca65t]

I'm running 0.032" with Pertronix. Works well in race car with rice carb. No fouling ever.
I'm running the old style 25D distributor with old-style side-exit cap (made for solid core wires). And, or course, solid core wires.
I'm using an American GM style coil ($15) and external ballast resistor.
Your coil looks like the "ho-po" coils they sell in Summit Racing catalog. Intended as a boost for normal American cars.

 

[vping]

I'll be running this; the 25D, NGK Platinum plugs .032", Silicone wires, Top exit cap, and a Lucas sport coil.

Ballast. I'm guessing that is the ceramic piece in my pic that is mounted to the fender? I don't need a seperate ballasted resistor correct? I can take all that off and mount the Lucas coil in typical fashion?

 

[aeronca65t]

As far as I know, the Lucas coils are internally ballasted, so you do not need an external ballast resistor.
You may want to go to the Pertronix webpage and see if they have anything on this.

Go here and click Support:

https://pertronix.com/

 

[Bugeye58]

Vince, why use the platinum plugs?
Jeff

 

[vping]

Somebody recommended them and not knowing any different, I got them. Should I not run platinum?

 

[Bugeye58]

Just a waste of money, in my opinion. All I run in my entire fleet, are standard NGK's, BP6ES for the most part.
Even in the Volvo's.
Volvo warns against using plats in the older engines.
Jeff