why do you need a resistor? the 72 has a built in resistor wire in the harness

Edited by Rockatansky - 23-January-2011 at 8:05AM

no the resistor shouldn't care which way the flow is

What coil are you using. Mallory makes different coils based on if you have a resistor or not. If you look at their online catalog, it doesn't say much, but I called them a couple of years ago, and they confirmed I needed the 29216.

http://www.malloryperformance.com/pdf/IgnitionCoilsCanisterStyle.pdf

Here is something I copied from Mallory's online knowledgebase:

Mallory Knowledgebase Question:

what voltage and what resistance coil is recommended for use with a unilte distributor thanks ken

Reply from Rep: It's not the voltage so much as the resistance on the primary side. You need at least 1.4 ohms (and preferably no more than 3 ohms). While it is true that more primary resistance will reduce the voltage, it is difficult to give an exact voltage because it depends on the output voltage of the alternator. Check the primary resistance of your coil. If it is between 1.4 and 3 ohms, you need nothing else. If it is less than 1.4 ohms, you need to add a ballast resistor or resistor wire (many pre-'74 cars came with a resistance wire from the factory) so that your total resistance (coil plus resistor) is at least 1.4 ohms. If your total resistance is more than 3 ohms it won't hurt the Unilite but your spark will be weak. RobbMc

I am running an MSD ready to run distributor, I am just using a Mallory resistor because its what the store had. I reread the directions and if I understand them correctly, you do not NEED a resistor but it won't hurt. So, I am going to install it today and hopefully it will solve my problem. Why else could it possibly be burning coils?

moose what's the part number of the coil, it's MSD?

I finally got around to measuring the voltage on the wires, the one coming from the key is 12 volts, the two from the distributor had nothing because I did'nt have a coil on it, and the factory resistor jumped from 0 to around 5. It's too cold to do anything else today

Thanks. I currently don't have a working coil, completely forgot to get one yesterday. No, I do not have a factory tach, pretty low optioned car. And I am not worried about performance right now as I am just trying to get the car in one piece. How diminished are we talking about though? Should I get another Blaster 2 coil or just get another cheapy one? And I'm sorry, I forgot about my other thread, didn't mean to "double post". Thanks guys.


Edited by moose0211 - 25-January-2011 at 8:29AM

I know in the case of Mallory (I assume MSD is the same), that a standard canister style coil comes in a few variants (different internal resistance of the primary coil). When I called Mallory years ago, I told them what I had, and they told me exactly which coil I should use. There was no price difference, but the setup has to be right.

Also, if you have the 12V bypass on your solenoid for the coil, you need to cap and stow that wire. You will know if you have it by looking at the solenoid -

There are the two large (battery cable wires) on either side. Battery power in, output to starter. There is a third (small) wire that is the solenoid switching control (tied to the key switch) which is angled 45 degrees pointing forward. On some models (mostly older points type ignitions) there is a fourth (this one is small, also) terminal sticking out. It's purpose is to connect to the coil to provide full 12V during cranking (when key is in "start") to get a hotter spark with with points type ignitions. This wire, if present, will need to be cap and stowed.

When electronic ignitions came into being, having two different voltages was not good for solid state circuitry. It's no different nowadays. It will fry an MSD just like it will a Ford Duraspark.

Dump the Blaster coils and move up to a MSD6 or better. The multi-sparker HEI will start your engine better and burn your fuel mixture for an increase in power and economy. As Warren Johnston says, buy the best parts you can afford and stop waisting your money.

Edited by GranTorinoMan - 25-January-2011 at 6:41PM

GranTorinoMan wrote: Dump the Blaster coils and move up to a MSD6 or better. The multi-sparker HEI will start your engine better and burn your fuel mixture for an increase in power and economy. As Warren Johnston says, buy the best parts you can afford and stop waisting your money. http://www.youtube.com/watch?v=8ADAPge3gwk

To be a little off-topic here, will a higher end MSD system be beneficial for a car that won't see the track or really high RPM? Daily driver?

GranTorinoSport wrote: GranTorinoMan wrote: Dump the Blaster coils and move up to a MSD6 or better. The multi-sparker HEI will start your engine better and burn your fuel mixture for an increase in power and economy. As Warren Johnston says, buy the best parts you can afford and stop waisting your money. http://www.youtube.com/watch?v=8ADAPge3gwk   To be a little off-topic here, will a higher end MSD system be beneficial for a car that won't see the track or really high RPM? Daily driver?

the multi strike gives up around 3000 rpm, so it does help at moderate use levels. easier starting, smoother running & more complete burn. by itself a 6-box may sidestep an ignition circuit wiring issue if there is one but won't fix it. also presents another part subject to fail, lots of boxes crap out. so many that serious race cars carry a mounted/wired spare that can be swapped with a couple plugs 

Ok,  got the MSD 6al ignition box today, it is the one with a rev limiter, and an Accel 8140C coil. I will hopefully be installing them tomorrow but I'm starting a new job so we'll so how far I get. My question is it comes with "pills" for the rev limiter, one for: 3000, 6000, 7000, and 8000. I am going to use the 3000 one for now but do you think I should get a 4500 or 5000 one? 6000 seems a bit high.

Edited by moose0211 - 29-January-2011 at 2:46PM

Right, thats what I was thinking and the 6al is all the store had. They do sell other "pills" right?