If you're looking for a great, cheap, electronic ignition system, that offers performance, this is it. I really like the idea of using your points as a trigger, because they never wear out since the power isn't flowing through them. If the module dies, you hook up the points, and away you go. The interesting thing is the price (the article says $25, but I'd imagine the price has increased since then), and there are three degrees of performance to choose from. Oh, btw, performance distributors, the company who makes/sells the DUI distributor, takes these modules and puts a Performance Distributors sticker on them, and sells them for $139!!

Here is the $25 module:



And here is the $139 module:



Gofastforless article:

In 1973 Chrysler made their electronic ignition standard equipment. Mopar guys have known the benefits of this system since it came out. If your car is Mopar powered you can still buy a conversion kit. Most people don't know the Mopar ignition box can be hooked to any distributor, including points. You're probably thinking that running an electronic ignition off of points defeats the whole purpose. If you're putting on an electronic ignition because you want one less thing to maintain then you should spend more money and buy a magnetic pickup distributor. If you want the power of an electronic ignition but don't want to buy a new distributor then hook it to the points. The points simply act as a trigger, the ignition module determines the dwell and handles all the current (which are the two biggest limitations of points). Since the transistor in the box handles all the current you will never burn the points, no matter how many amps the coil is pulling. There is one advantage points have over a magnetic pickup. If the ignition module craps out in the middle of nowhere you can just bypass it and keep going. I was curious how well a Mopar box would work on my Ford 289 with points so I tried it out.

The first step was buying a box. I called every parts store and junk yard in town to find the best price. Only one junk yard had them and they wanted $15 for the box and wires. Every parts store I called had Mopar style ignition boxes. Prices ranged from $14.89 - $48.99. You can also buy high performance boxes made by Mopar. They recommend the orange box for up to 6,000 rpm, the chrome box for over 6,000 rpm, and the gold box for all out racing. I decided to go with the $21.99 box from NAPA, (it's made by Standard Motor Products) model #TP50SB. As you can see in the picture it uses a huge transistor and heat sink. I looked up the specs on the transistor, it can handle a continuous 15 amps and a peak 30 amps. That's way more than any set of points can handle.

To wire it up you could cut the wires out of a junk yard car or buy a wiring kit from Mopar for about $20. I just wired it up with what I had laying around. Small female bullet connectors fit the pins on the box perfectly. First you should mount the box. It needs a good ground connection to work properly so scrape any paint under it and make sure the screws are tight. The cooler it is the longer it will last so keep it away from headers and other heat sources. Normally the box is wired up using a magnetic pickup, see pic. Pin 1 hooks between the ignition switch and ballast resistor, pin 2 goes to the negative coil lead, and the pickup is wired to pins 4 and 5. If you're wiring it up to points you only need three wires. Pins 1 and 2 are the same, and pin 5 is wired to the breaker points, see pic. You can remove the condenser if you want, I tried it both with and without the condenser and it made no difference. You need to change the point gap. A standard breaker point ignition fires when the points open, the electronic ignition will fire when the points close. If you don't regap the points the ignition will fire when the rotor is between posts on the distributor cap. Most likely you will have to make the point gap as small as possible. The smaller gap allows you to lower the breaker spring tension which will prolong point life. To check rotor alignment just cut a hole next to one of the posts on an old distributor cap so you can see the rotor. Hook a timing light to the plug wire closest to the hole. With the motor running, watch the rotor with the timing light. Rev the motor while watching it because the rotor position will change as the vacuum advance comes in. Ideally you want the rotor directly under the post when the ignition fires. Mine was pretty close after adjusting the points, but I wanted it right on so I repositioned the distributor cap. All I did was widened the alignment slot on the distributor cap so I could turn it a few degrees.

It only took me a couple hours to hook up the box. When I fired it up I was amazed to see 43° dwell at idle (750 rpm). I didn't think a motor would run with that much dwell. The dwell goes down as the rpm increases. At 5500 rpm it is 35°. If you do the math you will see that all it is doing is turning off the coil for about one millisecond because the spark only last about a millisecond. That is a poor dwell control. Ideally you want to keep the coil charge time constant which would show up as only a few derees dwell at idle and would get higher as rpm increases. A coil holds a finite charge, once the maximum charge is reached any additional current is just turned to heat.

Using a ballast resistor to control current increases primary resistance which slows the coil charge. At high rpm there is not enough time to completely charge the coil. If you need more spark at a higher rpm then you can reduce, or eliminate, the ballast resistor or get a coil with a lower primary resistance. This builds heat at lower rpm and can burn out your coil. A cheap solution is to hook a relay to bypass the ballast resistor when you stab the gas. Wire the relay to a switch on the throttle or if you have nitrous you can wire the bypass relay to the same switch as the nitrous relays. This gives you extra spark when you need it and keeps the coil cool when you're cruising.

This electronic ignition cost me less than $25 and runs as good as my $75 dual point distributor. Besides being cheaper, the only real advantage to the Chrysler box over points is lower maintenance. If you're looking for more performance then spend a little more for a TFI. END

I was doing some fascinating reading over at gofastforless dot com. I found a section about a Chrysler module from the 70's that offered great dependability and exceptional performance.

Then, while poking around the tech section of fordsix, in what used to be the pages of classic inlines, I found the ignition module they were selling was simply the Chrysler module repackaged. That says something.

 

That is only part true.
The point contacts will not wear out or pit like they do when they have power going thru them
BUT
The plastic rubbing block does wear! This will change the gap that changes the dwell and back in the day also changed timing.


It is because of that is why they went to electronic dist.


BTW I tried one of them MOPAR boxes on a car that ran a electronic set up that would not start. Still did not start after wiring in the box and think it was a bad pickup coil in the dist.
Because I had to move the car and had a ready to run dist I dropped it in with out a box and never changed it back after a pick up coil change.
Dave ----

 

The point in the article was that points don't suddenly fail as electronic ignitions do. You notice a change, a loss of power, etc., and they continue going for a long while. Not so with the e.ignition.

I'm not quite sure what you tried to say in the rest of your post. Your English composition is poor.

 

First I have to say I did not read the full post, just the top part as I have done that swap before but just was to replace 1 box for another.

That MOPAR box swap was big in the 80’s that Dr. Jacobs PHD. E.E. put out (new print) https://books.google.com/books?id=9N0eGL0dN1MC&pg=PR4&lpg=PR4&dq=dr+jacobs+ ignition&source=bl&ots=Pk5ipp61We&sig=zEYKx-6AP6tTVJL0Y3HBWgOJS54&hl=en&sa=X&ved=0ahUKEwjRsLbu _5nTAhVF6CYKHWAPAoEQ6AEIUjAJ#v=onepage&q=dr%20jaco bs%20ignition&f=false



If the block wearing down effects how points work and the motor runs different don’t you think it would affect how the box is going to work?
You are right when point start to go “out” there are signs I just don’t know if you would get the same signs when points are used to trigger a box is all and to point out they still wear all be it the rub block.

I do have a classic car that I run a duel point distributor in and the only thing I have that will run when we get hit with that EMF!
BTW if the condenser is right for the points you should have very little wear/pitting on the contacts.

The other point was it is not always the box that fails. Yes you can hook up power to the points to get running but you would also need a resister as points cannot take full 12 volts for a long time, were electronic box would need the full 12 volts.

Sorry I am not English major.
Dave ----

 

Thanks, Dave. You made some excellent points. I thought I found a flawless system, but you showed its shortcomings. That is the strength of the forum.

Again, thanks for chipping in.

 

It's all good, that's how we learn including me.


I have found nothing is bullet proof but what you go with when building something could make easier to get going again if something failed.
Like if the box failed to hook the points back up, I never gave that a thought.


Also with others posting you can see how they did something and pick what you think would work best for you.
In the end it is you that has to build it, fix it if it fails and live with it.


FYI that plastic block of the points pushing on one the side of the shaft wears the upper bearing. This will also throw off the point gap/dwell/timing. If you were to check timing with a light and it's jumping all over you would think the timing chain was bad till you put a dwell meter on it.
Dave ----

 

So if you get rid of the points, replace them with an electronic pickup to trigger this mopar piece, what do you have? A Duraspark II.

 

They are all the same just in a different package.
There are different ways the box is triggered as some dist. use a light that shows thru windows on the rotor. Think it is called hall effect?
Dave ----

 

I would stay with the points. If you're buying a DS2, most of them have the Chinese made magnetic p/u, which are subject to failure. It fails you are walking. Or, get an NOS motorcraft p/u on ebay. MotorCraft=30 years. Chinese=maybe 5.

 

FWIW, the Mopar NAPA boxes mentioned are still >$25:

TP50SB in eBay Motors | eBay

 

Nice find!

 

Yesterday I got the new Jegs catalog. I was flipping through it and there in the back, page 83H, I saw the module I was talking about. $50, and $75. It says upgrade a stock ignition for better performance and hotter spark.

 

They gotta pay for those race cars they're sponsoring I guess...

 

Where do you think most of the replacement points and condensers are made? I've been stranded just as many times with a points set up as I have with a DS II set up. The main difference is points will require adjusting and replacing as they wear, the DSII doesn't. The only time you need to mess with the DSII is when a part fails. I've owned a whole lot of DSII equipped Fords and I've only replaced 2 pick up coils and 3 ignition modules, because of parts failing. I've had to replace points and condensers a lot more then that.

No matter what you run, parts fail. It doesn't matter if they are old parts or new parts.

I've learned to just carry spare parts. On most of my Fords I carry a spare starter solenoid ( you can also just jump them if they go bad ) , ignition switch, distributor pick up coil ( on DSII ) , Ignition module ( especially on TFI equipped vehicles ) , coil , a couple roll pins for the distributor drive gear and a fuel filter. If you have room a spare starter isn't a bad idea either. And the most important thing to always carry is a AAA card!

The chrysler ignition box is a good unit. That swap has been around for a long time. I remember that being the "it" thing when I was a kid. It's a good low buck option. But it won't compete with most of the newer aftermarket MSD( and equivalent ) boxes. But it works and it's a whole lot cheaper.