Mopar electronic ignition swap...

[thrashingcows]

After taking the wagon to the street legal drags last week I decided to try changing my ignition system from the pertronix to the tried and true Mopar Electronic ignition. I picked up a junkyard 440 electronic dizzy a year or two ago from a 78 1/2 ton dodge van with a factory 440 in it!! Anyway I was just going to toss it in but decided I better open it up and check things out...glad I did!!

As you can see the dizzy had some rust in it. Never seen this kind of rust inside a dizzy before. I'm thinking maybe the van ended up in a river, or lake. And only some of the water got out of the dizzy and the rest caused all the rust. Anyway some time in the parts washer, and some time with some 280 grit sand paper and PB Blaster cleaned everything right up.

Reassembled everything with a good coating of motor oil and installed it.

 

[thrashingcows]

I then had to wire up the electronic control module. Got a darn good wiring diagram from some guy on moparts...when I bought a bunch of slant 6 stuff for my Desoto. Anyway real easy wiring, but needed to figure out where to mount the box. First I was going to mount it under the batter tray...but was looking at the 40 feet of wiring I was going to need and thought there had to be a better place. Didn't want to drill any new holes in the firewall, so was standing looking at things when I remembered a factory? or aftermarket mounting location on the back side of RB and B motors.

So off to my bucket of misc brackets and crap and found a bracket piece off a 93 Cummins A/C condensor. The holes lied up perfectly with the back bolt holes. Just needed to weld on a couple nuts and bolt it together.

And installed....

 

[thrashingcows]

Put on a nice new shiny control box and turned the key...and....Nothing!! Checked to make sure I had wired it up properly...yup. Checked my 12V ignition source...no problems. Then pulled a plug wire and installed a plug...no spark! So off came the new shiny control box and on went an original until from say 1975-ish? Anyway got everything reinstalled and turned the key and it fired right up...even though I still had the plug wire unhooked from the motor and plugged into the spare spark plug...

Tried to time the motor but could get a visual on the timing mark. Tried the white chalk/soap stone I've been using for years...nothing. Changed which plug wires I was using...still no sign of it. Tried black felt...again nothing. Not sure why I couldn't get a visual on the timing mark, but regardless I did the timing by ear and by vacuum. Took it for a drive...had to adjust the timing a couple more times..but finally got it hauling a$$.

Motor has never run so strong! Before I could not get the back tire to light up (no suregrip) Now I barely give it some throttle and that back tire is spinning. Also when I first fired the motor it was smoking badly...I initially thought I had hurt something in the old motor when pounding on it down the quarter mile. But after a few runs out on the street it seemed to clear up. I think it now has a hot enough spark to burn off the crud that used to build up on several of the plugs, and pistons. I think the old pertronic was just WEAK!!

Also found the vacuum advance canister on the pertronix dizzy was toast...sucking air. Think this is where my idle fluctuation was coming from. With the new Mopar ignition system...and a good vacuum advance canister...it's running nice and smooth now.

Very happy again with the way things turned out!!

 

[1978 NYB]

Great rebuild. So when are you going back to the track? I know you are drooling to find out how fast your ET/MPH is now!

:clap:

 

[thrashingcows]

Great rebuild. So when are you going back to the track? I know you are drooling to find out how fast your ET/MPH is now!

:clap:

Not sure if I'm going to or not. When I thought I had hurt the motor I was pretty bummed, don't want to truly hurt the motor. But I do REALLY want to see if things improved.

Also Found out why my shiny new electronic control box wouldn't work, it's a 5 pin box. I wired the ignition for a 4 pin box, and a 5 pin box will not work on a 4 pin system. A 4 pin box will work just fine on a 5 pin wiring system though. Just a FYI.

 

[BillGrissom]

See forabodiesonly for much info on the 4 vs 5 pin modules. The 5-pin were earliest and only lasted a few years. They used the dual ballast resistor, which is confusing. The extra resistor is 5 ohms, just to protect the module itself. Problems for people who swap the connectors with the 0.5 ohm one for the coil. Even more confusing, is that many after-market 5-pin modules have a dummy 5th pin, just to assuage buyers. As you say, the later 4-pin module works fine.

Not to throw water on your great effort, but for others who want to go electronic ignition. Look at FABO posts on using a GM HEI module. That lets you lose the ballast and run a better E-core coil, plus is simpler to wire. I like the 8-pin module and GM coil.