Hey guys, I am hoping someone can help me out. I am in the final stages of a rotary swap into a 1990 B-2200 truck. I just need to run my fuel and wire my MSD. I have a MSD 6A Sport Compact Ignition Box and two Blaster 2 Coils. MSD sent me a diagram on how to wire a single box to twin coils. The motor is a 13b with a 12a front cover and Distributor. It appears that there are two amplifiers on the distributor so I am wondering how I wire the MSD box. Has any one wired their ignition like this? I am hoping someone can give me some insight. I have attached the MSD wiring diagram.

I also have another 6A MSD box but it's not a Sport Compact Ignition. But I have heard a lot of people run two MSD boxes. Does this set-up make more power? If so how is this set-up run? It appears that there are three wires on each amplifier, but the MSD box only requires two wires. Which are the correct wires to connect to?

even in the diagram it says to use the ones that used to go to the stock leading coil from the ignitor. if you aren't sure which set is which i'd suggest browsing through a haynes or manufacturers manual. best of luck

What about running dual MSD boxes? what are the advantages to running the ignition that way?

the advantage would be that the leading and trailing coils would be firing at seperate times like they're supposed to. on a normal ignition cycle when the rotor gets to tdc the leading plugs (bottom of engine) fire first to get the rotor going the right direction, then the trailings fire to complete the combustion process and lower emissions. the engine will run fine with just one msd box, but emissions will be higher and you'll have marginally less power. running dual boxes is a lot more expensive so not done as often. so you can start driving it now though, the wires that went to the leading coil are black w/white stripe(+) and yellow w/blue(-). i'm assuming that when you run two msd boxes you'd hook up the wires from the stock trailing coil to operate it. best of luck and feel free to ask if have any questions

I am doing a swap into a pick-up truck, with a 13b. I do have the harness for a 2nd gen but not the first gen. So i don't have any of the stock wires off a carbureted car, just the distributor. If I understand properly, I need to run wires from the amplifiers on the distributor to the msd box. So I guess I need to first figure out which is the leading amplifier, second I need to figure out which two of the three poles on the amplifier I need. These are the things I need to figure it out.

If u have 2 boxes run them. Get rid of the amps. Now u have just 2 wires. one is positive and one negative. the leadig pickup is closer to the carb and the trailing is closest to you if your standing on the driver side and if the dizzy is in right. Word to the wise if u dont have rev limmiters get a aux tac. watch those revs too high and u could spin the rotor bearings/ stationary bearings. another thing not sure about the year of your 13b. some have 3 piece 2mm apex seals. when they get wore down the top piece can break fall out and ruin yor day. take it easy

alright, did a good bit of digging and this will take some explaining so let me know if i lose you somewhere

Attachment 17015

alright these are the types of plugs you'll need in the red box at the bottom. i labeled which connector is which post for the coils (which is what you'll end up connecting to your leading and trailing msd boxes) and obviously the wire from one plug goes to the corresponding spot on the plug to the ignitor for that coil. take notice for the designation for the plugs to the ignitor. b36 is for the trailing coil, b37 is for the leading.

Attachment 17016

this shows where the plugs connect to the ignitor on the distributor. in the image you're looking through the distributor so the trailing plug will be towards the front of the car and the leading plug will be just behind it. both are probably going to be under the alternator so you may have to pull that out to be able to see what you're doing down there.



best of luck man

matt

oh yeah, the wires that are originally supposed to go to the positive post of the coils are going to go to the red wires of the box, i can almost guarantee. as long as msd didn't go retarded red is normally the hot wire, so the coil ground wire will connect to the white one