What can I remove with MSD box?

[wsutard]

I installed an MSD 6AL Digital a few months ago due to some ignition problems. At the time I had to stash it under the battery as I had no other place for it.

Now my engine is out of the car and I want to rip out all the old components and then mount the MSD box in its place.

I'm assuming I can remove the ballast and the former ignition box without issue but I wanted to check first.

Let me know your experiences.

 

[1967coronet440]

Ballast and old ignition box can come out along with their wiring. Not exactly sure if there is anything else but I'm curious as well since I'm installing one with the new motor in my coronet

 

[dart4forte]

I installed an MSD 6AL Digital a few months ago due to some ignition problems. At the time I had to stash it under the battery as I had no other place for it.

Now my engine is out of the car and I want to rip out all the old components and then mount the MSD box in its place.

I'm assuming I can remove the ballast and the former ignition box without issue but I wanted to check first.

Let me know your experiences.
View attachment 415187

Go ahead and remove them. Just keep track of the wiring. You don't need the ballast resistor with an MSD. You may want to keep the box and the resistor in the trunk in case you are on the road and the MSD takes a dump. Good to have a backup.

 

[Jackpot50]

I got one now just need key on hot wire

 

[RJRENTON]

Once again, i reiterate my statement about MSD ignition system. WHY??? The Mopar electronic ignition system will work just as well and be easier to fix if/when necessary. But, this is just my opinion....I'm sure the MSD proponents will disagree....and some of them vehemently...but you pay your money and take your choice....its still America.
I'll stay with my old Prestolite dual point distributor.
Bob Renton

 

[Watchthis]

I'll say this about the MSD boxes. When I put my small block together, I installed an after market hei, to replace the points distributor. I'm running a comp cams xe284 cam and was getting extremely Rich smelling exhaust. I would smell like it after a short Cruise through town. I installed an MSD street fire and cured 85% of my exhaust smell. The multi spark really shines at idle. And the car starts after just two or three cranks with 25° initial timing. I've never had a stock Mopar, with much less timing, start this easy.

 

[RJRENTON]

Watchthis,
Rich exhaust is easily fixed by re-jetting the idle mixture/idle transfer circuit.....i don't mean the idle mixture screws but the idle emulsion tubes. Do you remember what the air:fuel ratio was? (Number). Sometimes rich mixtures are caused by cam shaft over lap, which causes exhaust gas to be reintroduced back into the combustion chamber cooling the incoming micture or diluting it to the point where it will NOT ignite, hence the "smell". Your fuel milage must be poor, if you have not changed the carb jetting. Spark plug coloration Is a tell-all as to the engine's "health". Once the fuel charge is ignited it will burn at a rate that is a function of chamber temperature, shape and mixture ratio.
I just prefer the "old" way....my RS23V0A *******, has a more radical cam, plus 11.0:1 compression ratio and the prestolite dual point distributor has no difficulty starting or running up to 6500 RPM and I get 12.5:1 air fuel ratio at speed. I get approximately 7-8 miles/gallon but i attribute this to the 4.10:1 Dana rear plus a heavy right foot.
Bob Renton

 

[Watchthis]

Watchthis,
Rich exhaust is easily fixed by re-jetting the idle mixture/idle transfer circuit.....i don't mean the idle mixture screws but the idle emulsion tubes. Do you remember what the air:fuel ratio was? (Number). Sometimes rich mixtures are caused by cam shaft over lap, which causes exhaust gas to be reintroduced back into the combustion chamber cooling the incoming micture or diluting it to the point where it will NOT ignite, hence the "smell". Your fuel milage must be poor, if you have not changed the carb jetting. Spark plug coloration Is a tell-all as to the engine's "health". Once the fuel charge is ignited it will burn at a rate that is a function of chamber temperature, shape and mixture ratio.
I just prefer the "old" way....my RS23V0A *******, has a more radical cam, plus 11.0:1 compression ratio and the prestolite dual point distributor has no difficulty starting or running up to 6500 RPM and I get 12.5:1 air fuel ratio at speed. I get approximately 7-8 miles/gallon but i attribute this to the 4.10:1 Dana rear plus a heavy right foot.
Bob Renton

I didn't know that. How do you rejet an AFB emulsion tube?66

 

[oldbee]

RJ is right I trashed a 20+ old Accel distributor with a new Summit Chrysler rig and that thing fires up faster than a new car F.I. rig. Well satisfied.

 

[RJRENTON]

There is a book, published by, i believe, HP books (look st Amazon.com) that describes the operation of the AFB and AVS carbs. Are you referring to the original AFB or the Edlebrock/Carter remake? They are similar but subtly different. The carb's idle and main emulsion tubes are part of the primary booster venturi assemblies. The idle feed tubes are pressed in assemblies inside the main emulsion tubes (larger brass tubes with holes drilled in the sides. The liquid fuel traveles up the small diameter idle feed tubes up to the idle air bleeds where it becomes mixed with idle air (emulsified) and travels back fown to the idle transfer slots and mixture screws. The idle feed tubes and idle air bleeds are calibrated restrictions. You must measure their diameters b4 proceeding. To increase the air bleeds they must be drilled. To reduce the idle feed tubes, they must be soldered closed and re-drilled to a smaller size. The order of magnitude is small....idle feed tubes are in the 0.035 inches in diameter range. Idle air bleeds can be smaller or larger depending on the results you want. Just about everyone has no idea this is how a carb is tuned. Changing metering rods and / or metering jets is part of the tuning process but not all of it. The only thing people do is the easily replacable parts.
At this point, i would suggest buying the Carter AFB book and study it to get a better understanding of how the carb works. What i mentioned is very important but time consuming and delicate accomplish, but in my opinion is well worth the effort.
Regards,
Bob Renton

 

[snakeoil24]

We all know points are easy to diagnoise if a problem occurs. THe Chrylsler Box works fine with a few modifications that are simple to do. Trigger wheel can be more stable. THe MSD box will fire a hotter spark and less likely to foul. THe one other advantage is the electronic setting of timing thru 6al Digital. If you go with a regular CDI you can not use a dial back timing light.. The plus and minus of each.. PS make sure you run vacuum on street engine taking vacuum below the throttle plates.

 

[wsutard]

So, this turned into something entirely different. For those stating "stock is good enough", I would agree but my ignition was cutting out at random times, while driving. I tried many things. MSD box was the only thing that got me back driving again. So, there are reasons.

 

[Nacho-RT74]

it seems you got an FBO ECU box ? I could be interested on it if you'll rid off.

OK, to install any aftermarket ign system everyone hacks up and splices wire anywhere which is not necesary allways

Using aftermarket multispark modules you can keep the ballast installed since the source from ign switch is just a "remote on" signal. These modules normally takes THE POWER straight from the charging system ( adviced from batt post, but would be more correct to get it from alt side to get a correct amm reading and load flow ). The remote on signal can be any voltage, so the ballast signal is quite enough. So use the existant + lead of coil wire ( blue on pre 69 cars, brown on post 70 cars )

If your are using existant distribuitor, you can keep the actual dist leads running to the ECU and hook them to the MSD system

The existant coil wires won't be used anymore to the coil, except the + lead which would be now the remote on signal to the MSD as mentioned previouslly and if a tach wire is present at - lead of coil, will be running also to the MSD provision. The wire between existant ECU and - lead of coil won't be used anymore, will be gone allong with the ECU plug, same as the rest of ECU wires ( but the dist wires what will be reused to the MSD


ON READY TO RUN DISTRIBUTORS is quite diff to source FROM the ign switch because these dist are sourced from ign switch as full power signal, not just a remote on signal, so you can either remove the ballast and splice all wires together OR keep existant ballas for stock look and jump the terminals with a jumper wire OR for a cleaner view, remove resistor element from the back groove on ceramic and isnatll there a jumper wire solding to the existant ballast terminals

 

[Nacho-RT74]

BTW, noticed you have a dual ballast resistor ( 4 prongs )... no need for this on your setup since FBO box are 4 pins modules which doesn't use the secondary resistor section. Although that takes the advantage if an ECU failure you can replace it for 5 pins stock modules from a regular parts dealer anytime, being ready for it

 

[condor74]

MSD boxes also have other features that may or may not be important to you. Cranking retard. Rev limiter. Spark retard for nitrous etc. I have 2 cars. One runs an old mopar electronic ignition distributor with cable drive tach. I run this to an MSD 7AL . My other car runs an old Mallory dual point distributor. Both work very well.