Question about electronic ignition for big block

[THE ZUKE]

Hello Mopar men,

I have a question about electronic ignition for big block.
On my 440, there is a depression ignition but not connected.
As soon as I will change it by a more efficient model  , should I order a model with depression or not?
What is the difference between the two operating principles?
Thank you for your answers.

Eric

[Chryco Psycho]

Sorry I don't understand your terminology  "Depression Ign"
Originally you had 2 types , 70-72 used points & 73-74 used electronic control
The electronic Ign is what most people now use , Again you have choices ,
The factory used an ECU [electronic control unit] , these are no longer very good as they are made in China & do not have the reliability they used to have when the factory was building 1000s / day
RevAnator makes the best ECU unit as a replacement for the factory ECU & uses the same Dist
Mopar has an upgraded dist fully adjustable available through Roseville
Firecore & MSD Also make Dist , Firecore is the better choice , I have had terrible reliability with MSD   

[Bullitt-]

Here's a nice package to get started..
Will need a harness to adapt for non electronic models
https://www.manciniracing.com/reiwcodi.html

https://www.manciniracing.com/wirharcopand.html

[Chryco Psycho]

Depression Ign you may be discussing the vacuum advance from your picture , I always leave them disconnected , I can get better performance & mileage with it disconnected

[THE ZUKE]

Sorry I don't understand your terminology  "Depression Ign"
Originally you had 2 types , 70-72 used points & 73-74 used electronic control
The electronic Ign is what most people now use , Again you have choices ,
The factory used an ECU [electronic control unit] , these are no longer very good as they are made in China & do not have the reliability they used to have when the factory was building 1000s / day
RevAnator makes the best ECU unit as a replacement for the factory ECU & uses the same Dist
Mopar has an upgraded dist fully adjustable available through Roseville
Firecore & MSD Also make Dist , Firecore is the better choice , I have had terrible reliability with MSD

Thank you @Chryco Psycho but OMG . I don't understand everything you're talking about. 

In my first post, I asked question about the piece surrounded by a red circle (on my picture).

I wanted to know if I need this model or an other one without this piece (for me the depression).

On my ex Mustang, this piece was connected to a hose (for the air, I guess). On my Cuda, it isn't connected ??

I think I didn't use the good american word (I'm sorry,  ), I thought distributor and vacuum advance when I wrote electronic ignition with depression.

For example : If this model will be good for my car ? : https://www.summitracing.com/int/parts/msd-85465/overview/year/1970/make/plymouth/model/barracuda

[Chryco Psycho]

NO Porblem , I was trying to understand the terminology you were using , I just leave the vacuum disconnected as I said above , I can make them run better this way

[Topcat]

Zuke,

Where you live, petrol is costly.

No doubt, fuel economy will be a consideration.

Take time to read this post made last week:

https://forum.e-bodies.org/engine-transmission-and-rear-end/4/vacuum-advance/9538/msg134336#msg134336

[THE ZUKE]

NO Porblem , I was trying to understand the terminology you were using , I just leave the vacuum disconnected as I said above , I can make them run better this way

Ok, I have again plenty of problems with american language (Specialy with technical language). 

Could you tell me if I wil change the distributor by a new MSD, it be better for the car ?

I don't know exactly which model/brand is in place (There is nothing noted on it).

[70 Challenger Lover]

I have to agree with top hat. That article is very useful and after you read it, you may choose to use the vacuum advance can. The circled item in your photo is vacuum advance. The hose is a vacuum hose from the carburetor and rather than push air into the can, it pulls air out creating a vacuum and advancing your ignition. Unless you race full time, you probably want to keep it connected.

The distributor you chose is good but I would select one with vacuum advance, you can still disconnect it if you want to but it is always there if you choose to connect it later. Buying a distributor without the canister limits your future options.

[Racer57]

If its working, then keep what you have with the vacuum line not connected.

If its not broke, don't fix it.   

[THE ZUKE]

Zuke,

Where you live, petrol is costly.

No doubt, fuel economy will be a consideration.

Take time to read this post made last week:

https://forum.e-bodies.org/engine-transmission-and-rear-end/4/vacuum-advance/9538/msg134336#msg134336

Thank you Topcat for the link, this article is very insteresting. I have to read again one or two other times (May be more  ) if I want to try to understand a plenty of things (I am not a ingeneer). 

But I understood the importance of emptiness. 

I agree, in France for one gas liter, we have to pay 1.60 € (around 1.82 US dollar). Very expensive in comparaison with you. Ten years ago, I lived in Dallas, it was praticly the price for a gallon. 

[THE ZUKE]

I have to agree with top hat. That article is very useful and after you read it, you may choose to use the vacuum advance can. The circled item in your photo is vacuum advance. The hose is a vacuum hose from the carburetor and rather than push air into the can, it pulls air out creating a vacuum and advancing your ignition. Unless you race full time, you probably want to keep it connected.

The distributor you chose is good but I would select one with vacuum advance, you can still disconnect it if you want to but it is always there if you choose to connect it later. Buying a distributor without the canister limits your future options.

Now I agree, I proposed this link before reading the article on the need for emptiness. There are not many models for a 440.

From what I know, for big block MOPAR, MSD is a good choice.

This link will be the good one (I think)  : https://www.summitracing.com/int/parts/msd-8387/overview/make/plymouth/model/cuda

[THE ZUKE]

If its working, then keep what you have with the vacuum line not connected.

If its not broke, don't fix it.   

I confirm that everything works good but the consumption is very high. When I had my ex Mustang, I changed the distributor and after the car had more punch. It responded better to acceleration.

[RUNCHARGER]

If your distributor is not worn out (it looks quite new) there is absolutely nothing to be gained by changing it to an MSD. I believe you will gain gas mileage if you connect the vacuum advance. You can hook up your vacuum advance by just buying a piece of vacuum hose but listen carefully for detonation (rattling noise) on acceleration.

[7212Mopar]

The MSD distributor you are looking is what MSD calls ready to run type. Meaning the electronic ignition and timing control is build inside the distributor. It is definitely an option if you are converting from the factory dual points ignition system and not to worry about ballast resistor using the factory electronic ignition system. Recommend you download and read the instruction first.

Looking at the pictures, the electronics on this distributor is only protected by the distributor cap just like the GM stuff. Also check out the installation addendum using power from battery and a relay trigger by the ignition switch.