Cannister coil for HEI?

I want to experiment with a 4-pin HEI module, eliminating the ballast resistor in the process. Is there a good choice for a cannister coil to run at full 12+ volts?

If you're in Northern VA, you can just come get an HEI module, heat sink, and coil I have sitting on a shelf in Frederick, MD. I rigged up an HEI triggered by my Mopar electronic distributor but decided to just buy an HEI distributor instead.

Thanks for the offer, but I have a module and heat sink that I wired in temporarily just to make sure it all works. I know an e-core coil would probably be a better choice, but would like to find a cannister that doesn't need a ballast resistor.

maybe something from MSD or pertronix ?
who makes the "blaster" coil ? i think there are a couple of companies out there that have canister coils for their ignition kits, [which bypass the ballast resistor] but i can't name them off the top of my [bald] head.

Blaster coils are MSD

thanks Pac.
are they 12 volt ?

Hei requires a coil with 1.0 to 1.5 ohms resistance.

https://www.summitracing.com/parts/edl-22739

I'm using a MSD Blaster coil 367-8222 https://www.holley.com/products/ignition/ignition_coils/street/performance_street/parts/8222

Internet information has been vague and at times contradictory. (No, really!) Some references say the ballast resistor is to reduce voltage to the coil, as with Mopar electronic ignition, while others suggest it depends on which type of ignition control module you're using. Still others say the ballast resistor reduces voltage to the points, if you've still got those. I suppose it could all be true. I read an ariticle about Mopar to HEI conversion that recommended the Standard Motor Products UC12X. I have one and it measures 1.2 ohms across the primary, but has "Use with ballast resistor" printed right on it. The SMP UC15T is marked with "No external resistor required", and I found only one reference to its primary winding resistance of 3.4 ohm.

Primary winding resistance is all over the place with coils in general. E-core coils made for HEI have resistance of less than one ohm. The low resistance lets the magnetic field collapse faster, resulting in a hotter, stronger spark across a wider spark plug gap. Looks like the HEI module would prefer an e-core coil, but I'd still like to find a compatible cannister. Maybe I'm making it harder than it really is.

FWIW, the electronic ignition system I am building for my 51's flathead consists of a mix of /6 and flatty distributor parts, using the MoPar pickup to drive a GM HEI module and an E core coil. It's a combo others have used and I know it works.

Quick Google search shows the old HEI in-cap coils as .5 ohm primary. I would think anything from.5 to1 ohm will function/live just fine. I did many GM HEI conversions in the past...ran 12 volts to the cap and called it good. Jeg's HP HEI coil
https://www.jegs.com/i/JEGS/555/401...hRcvV4nBJdsSQKplWDtmrkhWkhBoCRDMQAvD_BwE

I sent the question to Standard Motor Products, and got this reply (they reference Mopar ignition because I asked about replacing it with an HEI module and SMP's UC12X coil):

"Electronic ignition systems, whether factory Mopar or aftermarket, don't utilize breaker points, thereby not actually needing a ballast resistor to control amperage through the pickup coil. And while ignition coil life may be compromised without a resistor, the additional secondary voltage (at the spark plug) is increased which generally improves power. So does your application require a ballast resistor? Quite simply, if your distributor has breaker points the answer is yes; if not, the answer is no."

Assuming this is correct, it sounds like Mopar used a ballast resistor with electronic ignition to maximize coil life even though it maybe wasn't necessary, while providing a slightly weaker spark. And for coils marked for use with a resistor, that's only necessary if using breaker points.

that's an interesting reply from Standard.
at one time, i had a book from Jacobs, at least i think that was the name, that talked about ignition systems. not sure they are still in business these days.
anyway, i'll have to dig around and see if i can find that book, and review it again.

Please do and let us know, But then again technology has changed so much I'm not sure it would be relevant

Christopher Jacobs Phd, the Doctor's Guide to Optimizing Your Ignition Systems is the name, IIRC. I have it, somewhere, a lot of what he says and does int eh book is still relevant. The specific parts recommendations might be out of date as those parts are no longer made here and as we all know the quality has gone to ... well you know where it went.

I believe Mallory bought him out a long time ago, then they got bought out and none of his proprietary stuff is available in the US, last time i looked you could get it from Australia. It was a neat concept that used the plugs as a sensor for the computer in order to tune the ignition.

Here's the book

https://www.amazon.com/Publications...nformation-troubleshooting/dp/B002TT6BYO

I find it interesting as well only because the ballast resistor has nothing to do with current flow through a pick up coil? Pick up coils create their own signal telling the module when to switch the coil primary thus creating spark.

Maybe they just used the wrong terms in the reply but still. If you're replying to a technical question you should get the terminology correct or the whole answer becomes suspect.

I agree. It bugs me that they mark the coils for with or without ballast resistor then say it's not the coil that matters, but other components of the ignition system. If they don't know what kind of ignition the coil is going in, labeling the coil is irrelevant.

There are a couple of good articles out there on the ignition system. The ballast does reduce the voltage to the coil, but also that controls the current because Volt =I(amps) x R (ohms). But the other factor is the inductance of the coil. It really is an RL circuit. Higher the inductance the stronger the magnetic field can be, but the longer the time constant of charge rate. The inductor initially resists the current when points close but rises exponentially. Once the coil is saturated any further current into it just creates heat. When points open, the magnetic field starts to collapse. When this happens the primary winding has an induced back voltage that rises to 200-400 volts depending on the resistance of the primary, the inductance of the coils, strength of magnetic field (coil construction and charging time) and the capacitance of the condenser which absorbs the voltage spike. With a turn ratio of 100 or more. The 200-400V becomes 20 to 40K voltage with just milliamps of current on the secondary. Energy is conserved, neither created nor destroyed, just losses from efficiency factors (heat loss, etc).

Points can only handle so much current interruption before they wear from the high current interruption. So the system is tuned for that. Obviously as RPM rises the time to charge the coil drops, the magnetic field is less and secondary output voltage drops off.

So back to your electronic system. The box could have the ballast built in. The box could/can control current and dwell time for output so external ballast not needed. When matched to the coil and there are coils built that can withstand high current better.

Mopar performance Chrome box used a low .25ohm ballast but was not meant for street, because at low rpm dwell was longer and the coil was being saturated and the box would overheat, and the inductive kick back was higher. Box or coil could fail. But at high RPM with less time to charge, the higher current to the coil insured a better magnetic field charge to the coil and kept a higher secondary voltage to fire spark plug. So optimized for racing.

So I think it is best to use the recommended coil that the ECU manufacture recommends, and you can choice to go without ballast if you want.

As far as what standard was saying, I think they were explaining that the pickup coil is not affect by the charge current. It is not. Only the coil is. While in a points system the points are affected by charge current too. The points are the limiting component that set the ballast and coil resistance to keep current flow in spec. Electronic if rated and protected right, only has to limit current for the coil as the limiting component.

Hope that helps.

Don't know of any. Ford TFI coil seems like a good route to go but doesn't have the OE look(if that's important) of the canister.

Well explained sir

as to the chrome box not being for street use, i used that box on my 38 plymouth coupe for 10k+ miles, 360 [e58 engine] 727 combo way back, and it worked flawlessly.
i always thought it was the gold box that DC and Mopar performance said was not for street use ?

You might be right, was going from memory. But if you used a higher ballast it would limit the current.

a ballast was used, but i don't remember what it was.
in that setup, i used one of those accel big yellow super coils.
i don't remember if using that coil dictated a certain ballast. that coil sits on the shelf, so if i ever use that again, i will have to research what ballast to use with whatever ignition system i go with.