Duel point distributors?

[Frank Gooz]

I have spent some time looking in our pass posts and in the technical. I would like to know if there was a duel point distributor used in a 23 inch engine?

I what seen aftermarket one for a 25 inch, Very hard to find parts it was a mechanical advance also.

 

Thank you

[plymouthcranbrook]

I have kit that was designed to change a single point system to a dual point for a 23 inch block. Seems to have all the parts and instructions as well.  I keep thinking about getting a spare distributor and seeing if I can get it to work. But it runs so well on the single point I just never have.

[Loren]

Seems like a lifetime ago now, I put a Mallory Dualpoint on a 1972 Capri 4 cylinder. It went about 100,000 miles with zero problems. This in a day when 6,000 miles was the norm for tune ups. One set of points took the wear so I moved the other points to that position and installed one new set in its former place.

When points open they are breaking a circuit and there is a spark. The spark vaporizes a tiny bit of metal each time so after a while they wear out.

In the dual point system one set of points serves to open the circuit and the other closes it.

The next big thing in ignitions was the Capacitor Discharge Ignition. This fundamentally changed Charles Kettering’s battery coil ignition. Where battery coil built up a magnetic field in the coil when the points closed then when the points opened the field collapsed and created a spark. In Capacitor Discharge the energy is stored in a capacitor then discharged through the coil which acts as a transformer to step up the voltage. The resulting spark is very short and fast acting because it is not the product of a magnetic field collapsing but of the discharging of a capacitor. Using the points as a low voltage low current switch to trigger the circuitry controlling the capacitor caused them to last practically forever, the limit being the rubbing block wear. Ignitions such as Delta Mark Ten and the kit forms (Archer and Heathkit) could be tuneup free for seriously long times. The fast acting sparks kept plugs cleaner too.

I’ve been looking for a Mallory Dualpoint for a Plymouth for some time with no luck.

Mallory used to be based in Carson City where I used to live and you could go to the factory and have them “make up” stuff not in their catalog. Some mismanagement caused a collapse and bankruptcy of this fine old company. The successor moved everything to Ohio and is slowly phasing them out of business favoring their other brand ACCEL.

My experience with the Delta Mark Ten dates back to the 2 stroke SAAB.

Not being able to find a Dualpoint I thought I’d try for a Delta since I knew they made 6 volt positive ground systems.

I found a guy who had a negative ground version for sale and since he was into repairing them I asked him what it would take to convert it. He told me it could be done. Before he started I found a 6 volt positive ground system in a photo of a car advertising something else on eBay at French Lake. I made a quick deal for it and sent it to him. It needed repair too and he was able to get both working properly. So now I have my ignition covered times two.

The Delta system has a ribbon cable which connects to the stock coil. You simply remove the stock wires and attach the ends of the ribbon to the coil and the original wires to the adjacent location on the ribbon cable ends. If you want to go back to the stock ignition for some reason you reverse the process. The Delta Mark Ten B had a push button switch on the end which did that for you. However, Delta never made a 6 volt version of the “B” model. (So don’t bother looking)

Of course if you are going to go 12 volt negative ground you can get Langdon’s HEI. For my Coupe I wanted to stay with 6 volt. While Langdon’s doesn’t mention it, you can hook up an MSD unit to the HEI. This gives you multi spark up to 3,000 rpm. Summit racing sells a house brand version which is cheaper and has great customer reviews. MSD also sells the four prong HEI modules that these ignitions use. I am not sure if there is any advantage to them.

So there are plenty of ignition options available for you, these are just the ones I know about.

Have fun!

[Dodgeb4ya]

I also put a Mallory dual point three lobe cam distributor in my 51 Cranbrook 218. That was in 1968.

I bought it new..it's still in that car and has always been trouble free.

Edited September 28, 2021 by Dodgeb4ya
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[Los_Control]

Just now, Dodgeb4ya said:

I also put a Mallory dual point three lobe cam distributor in my 51 Cranbrook 218. That was in 1968.

I bought it new..it's still in that car and has always been trouble free.

Ahh 1968 ... that was he year I got mad at my parents and ran away on my tricycle   Pretty sure it was dual foot powered not dual points