Hi folks, I have a quick question for those "in the know". I am considering replacing my points with the Pertronix Ignitor II module. Everything I have read says this is a good thing and I may even gain a few ponies with it (as much as 10-16%). My question mainly is which one to buy? There are modules for single and dual points systems as well as one to delete vacuum advance. I have been told by a friend of mine that I should get the dual points version that gets rid of the vacuum advance and that one will perform best. For the record, I have a 71 Grande with the stock 302 and single points setup. Any recommendations or experiences with the product you would like to share would be appreciated. Thanks in advance.
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John H. Bettencourt
1973 Mustang Custom Convertible
The vacuum advance is critical for a street driven car!
Since you have a single point distributor, you'll need the 'kit' for that distributor. If your original distributor was dual point then you'd need the corresponding kit.
Tominator, while I tend to agree with you, perhaps I should be asking another question. Due to my own ignorance, what exactly does the vacuum advance do and why do I need it? I was told I could get rid of it and plug up the holes and my car would still run fine, perhaps even better. I was also told that although my car came with a single point distributor, that going to a dual point system was also desirable. Is there a reason I could/should not? Was I duped? Please advise. Thanks.
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John H. Bettencourt
1973 Mustang Custom Convertible
I know that the vaccum on my MSD, plays a huge part in the timing curve. When i take the vaccum off, the car is sluggish, when connected the vaccum jumps the timing up for more HP. The cool thing about the MSD, is that you can change springs in the distributor that adjust the agressiveness of the timing curve. So even if at low vaccum if still will peak the timing when you want it.
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69 Mach 1
Summit Racing Headers
Mallory/MSD ignition
Edelbrock 650 carb
Top loader/4 speed
Edelbrock Performer Intake
Black w/ Gold stripes
A dual point distributor is a different distributor than a single point. The only reason a dual point was ever made is to help with a problem know as 'point float.' At high RPM the mechanical spring of a single point could not react fast enough and caused misfire and other related timing problems. With a dual point each set of points each spring only worked at half the rate and that prevented floating the points.
There are two factors that adjust timing in a non EFI setup. The weights in the distributor react to centrifugal forces against a set of springs. The points or electronic trigger are mounted to a plate that is connected to the weights. The higher the revolutions the further out the weights swing and the further your ignition advances.
The vacuum advance senses the vacuum in the intake. At idle, cruise and acceleration the vacuum is very different and so is the amount of timing you can safely run.
Both the springs and the vacuum advance can be modified for differences needed in the advance curve for a modified engine, but the proper operation of both are critical in a street motor.
The petronix system just eliminates the points. Instead of a mechanical trigger it is an electrical trigger. The electrical trigger is far more accurate than the mechanical and so the claims of increased mileage, etc.
IMHO it would make more sense to convert it to a factory Ford electronic ignition. Parts are cheap and the swap is easy.
WOW, thanks for the awesome response Tominator. I now completely understand what vacuum advance is for and why. I appreciate the info. I will be going with the single point setup with the vacuum advance. While it is enticing to go with a factory Ford setup, I still want a factory original look, the Pertronix fits under the original distributor cap and no one is the wiser. Thanks again.
BTW, thanks to 69Mach1351w too.
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John H. Bettencourt
1973 Mustang Custom Convertible
Nice job Tominator, I'm running the Mallory version under my stock cap and everyone asks why there is 3 wires going to my distributor. I just tell them its rocket science
Also, one side note on this topic. The actual electronics in the ignitor is the same for any of the versions you get. The only difference is the aluminum base plate the "magical black box" is connected to. Believe me it's alot easier to match what ya have, than to get the wrong one and think "humm if I just drill here, and file here, I can get it to work." Needless to say, the 200 mile round trip back to where i bought it was well worth it before i did the whole 'you break you buy' thing.
IMHO it would make more sense to convert it to a factory Ford electronic ignition. Parts are cheap and the swap is easy.
Tominator what era set up would you sugest I was looking at the electronic option for my 66 windsor but haven't as yet found out much about late model swaps (every one wants to sell me a new[read expensive] aftermarket setup) any info woold be apreciated
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Wimblton white 66 coupe C code 289 auto
97 Jeep Wrangler 4.0 auto, lift ,winch,33's etc
04 Holden VY SS 5.7 auto (wifes)
88 KLR 250
DISCLAMER:
Please feel free to ignor all advice/information offered
I could be wrong...... I have been before.
Krankie, he's probably referring to the Duraspark. These were found on US Fords from 75 to around 85. Don't know about the years " down under". Hope this helps.
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65-2&2, 63 Falcon vert, 32 coupe, 76f-250 4&4,72 Ranchero GT-Some is good,more is better,and too much is just enough.
Electronic Ignition Question... 
