I just looked up the pertronix kit... Summit has it for under $80. Be hard to go wrong. Not sure you could do the Duraspark for that little!
Someone online gave reasons for using the pertronx II for the upgrades... its $112.99
https://www.summitracing.com/parts/pnx-91281/year/1971/make/ford/model/f-100?rrec=true
Not sure if either need a different coil, but its under 40 for the Pertronx brand.
I also think this post borrowed off the web says it well.
I have run the duraspark on a few Bronco's and have had a few problems over the years. I bet I have replaced 2-3 units on different trucks for various reasons. That being said if you keep a spare you can not go wrong. Can get parts, probably in stock, and any parts store.
That being said I have also run Pertronix on one of my trucks as well as my GT350. My dad has converted all his over to Pertronix as well and I have never had a module go bad. May be blind luck but they are damn simple and work great. Would have to order parts if you DID need them, but you can carry a set of points/condenser, as a emergency spare
Both are pretty easy to install once you know how. The down side on the Duraspark is you have a module to put somewhere safe from heat. On my GT350 I wanted the engine compartment mostly stock so the Pertronix rules there with no big module to store somewhere.
I have nothing against the Duraspark based on my experience, that being said I would run Pertronix if I was in your shoes.
In reply to 03Panther :
I really do appreciate all of the information. Your diagrams regarding spark plugs were awesome. I didn't know any of that, so, for you to take the time to draw that out, is truly helpful!
Really? All this distrust in point ignition? How did we ever get anywhere in the first 70+ years of the internal combustion engine?
outasite said:
Really? All this distrust in point ignition? How did we ever get anywhere in the first 70+ years of the internal combustion engine?
Oh we got places but there was a lot of futzing around to do it and a lot of fuel that went unburned in the process. I think I'd contain the scope creep for now and just freshen up the stock setup for the time being. Eventually a change to something a bit more modern seems like the smart move. For now a set of points and a condensor would be part of my plan were I in dyintro's shoes.
For now, I'm going to install the new parts I have. Going back to the original question, did we decide on the preferred/recommended plug gap?
A pertronix ignition will not provide a hotter spark.
A pertronix will not fix a bad vacuum advance
A pertronix will not fix a wobbly distributor
Recommended plug gap is as big as you can run without misfires.
I'd try .035" to start and if you feel like playing around you could widen the gap a bit later on. This is based on internet research for a '70 truck 302 installation. Down the road you could play around with a wider gap when you get some other supporting parts into the mix like a hotter coil and breakerless ignition.
Most point based ignition systems plug gap was .030 - .035. I would start with .032. More important would be dwell (based on point gap) and timing. This after checking distributor shaft for excessive play, mechanical and vacuum advance operation and lubrication of the point cam lobes.
Monday mornings at the shop would find cars/trucks that had been towed in because someone had attempted a tuneup with not enough knowledge/assistance.
dyintorace (Forum Supporter) said:
For now, I'm going to install the new parts I have. Going back to the original question, did we decide on the preferred/recommended plug gap?
Looks like .034 for all full size Fords with the 302. Point gap should be .021.
https://www.tpocr.com/fordfs1.html
Mr_Asa
SuperDork
12/31/20 1:01 p.m.
outasite said:
Really? All this distrust in point ignition? How did we ever get anywhere in the first 70+ years of the internal combustion engine?
By cranking an engine for 5 minutes at a time when cold?
Mr_Asa said:
outasite said:
Really? All this distrust in point ignition? How did we ever get anywhere in the first 70+ years of the internal combustion engine?
By cranking an engine for 5 minutes at a time when cold?
Ford's point set use a little plastic bushing that insulates the points. I've had two sets fail within a week of installation. The new ones are many times worse than the OEM stuff was. A switch to the Pertronix kit solved the problem permanently.
Not 302 based but still Ford.
I converted a Ford 2.8L V6 from points to Duraspark dist. ignition system. The neat thing about the system is there are more than one way to wire up the ignition. The one that I found results in the spark being retarded 6 deg. when you first crank the engine over but reverts back to normal spark advance once you release the key when the engine catches. It was designed into the ign. module so that cranking a hot engine was easier.
What first happened was I found a bad wiring diagram on the internet (No, cant be!) and wired the ign. system up so that the timing was advanced when cranking the engine. The ign. module retards the spark when the engine was running so I set the timing with 6 deg. more advance not knowing the module was retarding the timing. The engine would crank very slow when hot but OK when cold. I spent weeks trying to figure this problem out. I thought it was a weak starter or low voltage.
Once I figured it out and revised the wiring she starts great cold or hot!
Toyman01 (Moderately Supportive Dude) said:
Mr_Asa said:
outasite said:
Really? All this distrust in point ignition? How did we ever get anywhere in the first 70+ years of the internal combustion engine?
By cranking an engine for 5 minutes at a time when cold?
Ford's point set use a little plastic bushing that insulates the points. I've had two sets fail within a week of installation. The new ones are many times worse than the OEM stuff was. A switch to the Pertronix kit solved the problem permanently.
If I switch to the Pertronix kit, should I go ahead and upgrade the coil too?
Toyman01 (Moderately Supportive Dude) said:
Pertronix makes a drop in electronic conversion kit to replace those points as well. Takes less time to install than a set of points does.
Probably also better than a Duraspark. My Duraspark experience consists of owning multiple ignition modules to swap them out when they overheat to make the full 200 mile trip back and forth to college.
outasite said:
Most point based ignition systems plug gap was .030 - .035. I would start with .032. More important would be dwell (based on point gap) and timing. This after checking distributor shaft for excessive play, mechanical and vacuum advance operation and lubrication of the point cam lobes.
Good advise, but he's brand new, and doesn't know what you just said. Not sure I can explain "dwell" over a computer, but this young man seems to be a good student. I would suggest including some simple explanations with good advice.
I haven't touched points on a car in many many years, and on the chopper, I set them at night, by spark color at the points, and by ear. As long as I road her gentle, they would last. but if ya really hit it, the gap would close up, so I adjusted the points on the side of the road A LOT. Never needed the spare I carried... just adjust and tighten!
Mr_Asa
SuperDork
12/31/20 7:18 p.m.
In reply to AnthonyGS (Forum Supporter) :
Use a GM HEI module. Mine last for years.
Toyman01 (Moderately Supportive Dude) said:
Ford's point set use a little plastic bushing that insulates the points. I've had two sets fail within a week of installation. The new ones are many times worse than the OEM stuff was. A switch to the Pertronix kit solved the problem permanently.
I haven't bot a set of points new in over 25 years. Considering how aftermarket part quality is to day, I bet new points are pretty bad! I had not thought of that, so the Pertronix plan is looking good!
dyintorace (Forum Supporter) said:
If I switch to the Pertronix kit, should I go ahead and upgrade the coil too?
I would probably do this one step at a time. Change to the Pertronix kit in place of points but leave everything else as it was. Then change the coil when you're sure the breakerless setup is working well. At that point you could open up the plug gap.
But to just get this running I wouldn't bother unless the existing coil turns out to be defective (they can die so it's not an impossibility).
bentwrench said:
A pertronix ignition will not provide a hotter spark.
A pertronix will not fix a bad vacuum advance
A pertronix will not fix a wobbly distributor
Very true! It will allow a larger gap, that in itself provides the hotter spark.
The "hottest" ignition system in the world does not make a spark any hotter... the gap and conditions when the spark jumst the gap will only "use" as much as it needs. As long as your ignition system can provide what the spark needs, more will not change a thing.
You can gap the plugs wider with the pertronics setup than you can with a mediocre points set up, that effectively makes a hotter spark.
The Pertronix eliminates the ballast coil (that drops voltage to about 9V if I remember right) and runs at full 12V (nominal). Depending on what stock coil he has, he may need a different coil, and the Pertronix coil is a bit "hotter" than stock, allowing for more gap, (sometimes)
pres589 (djronnebaum) said:
dyintorace (Forum Supporter) said:
If I switch to the Pertronix kit, should I go ahead and upgrade the coil too?
I would probably do this one step at a time. Change to the Pertronix kit in place of points but leave everything else as it was. Then change the coil when you're sure the breakerless setup is working well. At that point you could open up the plug gap.
But to just get this running I wouldn't bother unless the existing coil turns out to be defective (they can die so it's not an impossibility).
Some stock coils either have too much, or too little (I can't remember) resistance to run right the way the Pertronix is set up. Some are ok as is. There is info on how to "ohm" it and see, but I would assume we'll have to teach him how to use a multi meter, unless thats something he knows - its super easy to do and a $3 meter from HF will do it!
Otherwise, spot on!
Mr_Asa said:
In reply to AnthonyGS (Forum Supporter) :
Use a GM HEI module. Mine last for years.
I like the HEI route as well, but I think more expensive, and I think the Pertronix may be simpler for the new guy! Def. a great setup. I would have gone that way for my 460 truck, but the duraspark was already started - just wired wrong. Burnt two modules trying to get that right!
In reply to jimbbski :
I did a lot of looking before figuring out the best wiring for my converted 460. The po had wired it by a bad diagram!. The 460 is one that REALLY likes the retard while starting function, but I think his will be fine without it.I did find and redraw some good diagrams, when I take the time to dig in and find 'em.
I prolly found some of the same wrong ones you did! But I persevered till I found the good stuff!
