MTFCA Forum

I have seen a very interesting device for adjusting buzzer coils, the ECCT tool.

Nice, but for my taste this is a little bit too pricy. I will not pay 400-500$ for such thing when I need it possibly 1 time a year.

So I will try to do it in "old way", by measuring the drawn current and setting it to approx 1.5 Amps. I also plan to build a little testing device by myself, with high voltage contacts for seeing the spark.

Is this process somewhere described in detail? Perhaps a wiring schematic if it is more than just applying DC voltage to the coil?

I wonder which voltage I should apply.
When running on BAT, the coil receives intermittent 6V voltage. But MAG gives much higher AC voltage of up to 23V or even more. So which voltage should I connect? 12V DC would be somewhere in the middle between BAT and MAG, so I tend to use 12V.

Measuring the capacitor is also relatively simple. I place a stripe of paper between the buzzer contacts (to keep then "open"), then I can use a simple capacitor tester connected to upper and lower contact (at the mounting bolts, of course). 0.47uF is big enough to be measured with every better multi-function multi-meter, able to also measure capacitance.

But it would be helpful to know a reliable procedure. My coils are currently working fine, but this will allow me to test the device I build.

See other post
Norm

Hi Norm, one of the (if not the) most viewed posts is all about home building a coil test unit. Plenty of diagrams and explanations there.

Horror of horror but I use an old school spark gap box myself ! Adjust the coils until I get a nice crisp noise and healthy spark jumping across a 1/4 inch gap at about 1.5 amps. The trick is to get a set of 4 "more or less" sounding the same (cringe from the specialists).

There is a wiring diagram to make one that was posted a few years ago now on the old forum. It is very simple to make. I am sorry but my forum search skills are not quite up to it to find it now.......

Cheers and seasons greetings from New Zealand,

Kind regards Adrian

I have attached a patent design of a 1917 spark coil and spark(ing) plug tester, per a google patent search. Patent number 1231970. There is a wiring design with the patent papers. enjoy.

(part 2) - I have attached a patent design of a 1917 spark coil and spark(ing) plug tester, per a google patent search. Patent number 1231970. There is a wiring design with the patent papers. enjoy.

I don't see a meter in there. (Kind of tough to see actually). So isn't this just a fancy buzz box?

This design uses two meters: the infinitely variable Mk1 eyeball light detector and the aural sensor meters (eyes and ears) to see and 'judge' that the spark being made is fat and happy.

Even with a meter showing the amps, adjustment in the old buzz box approach still needs these meters to be used as well.

Allow me please, to bore you. Attached is a buzz box adjustment and coil tester using DC voltages. The analogue meter is maxed out at 2 Amp. The meter should be good enough to get the proper setting. The meter is at the input side of the coil. Now that the message has been delivered, please place knives where appropriate.

John
No knives, just the facts.
As has been observed in the past multiple times on this forum, this type coil tester has no provision to see the time and space relationship of the coil spark output. That feature is critical to Model T Ford coil point operation.
Ron Patterson

Like any buzz box adjusted coil, the coil will allow the car to start and maybe even run fairly well, but not optimally.

Art Mirtes.

As has been observed in the past multiple times on this forum, this type coil tester has no provision to see the time and space relationship of the coil spark output. That feature is critical to Model T Ford coil point operation.
Ron Patterson

Quite right, it is far from the 'ideal' solution, but if can be made to work 'near enough' with practise, even if not actually 'optimal'.

The hand cranked tester would be the next level up then the HCCT for the top.

I have to admit that I am dense. I guess, it could be stated that I am technology challenged.

So Please help with expanding on these statements. What are you stating?

1. "...this type coil tester has no provision to see the time and space relationship of the coil spark output." Is quantum physics involved in the operation of the ignition system?

2. "... (allow) the car to start and maybe even run fairly well, but not optimally." A stock model T was built to be simple and cheap to produce. It was not designed to be a high performance car. On today's roads - level and smooth - reaching 35 to 40 mph with a stock car - is that optimally? And climbing a moderate grade in High Gear?

3."... hand cranked tester would be the next level up then the HCCT for the top." Are there two devices that have hand cranks?

Thank you

You can adjust them any way you want, same as a carburetor.

you know, Pat, that is a perfectly accurate and succinct answer...there's simply nothing left to say after that.

I'm going to have to remember that one!

I don’t understand all the controversy. Just plug in your code reader at the OBDII port underneath the steering column on your Model T and it will tell you if the coils are working properly.

If you do that, the Proprietary Software Police (PSP) will break down your door at 3 AM and take your coils and timer and kidnap your dog!

"Just plug in your code reader at the OBDII port underneath the steering column on your Model T ..."

I believe that is what the new replacement of the old guard of Model T Owners want.

Unfortunately the answer is not always 42.

The astute and frugal owner will be satisfied with nothing less than a smooth, even purr.....

Is the ECCT tool a satisfactory tool? Where can I get one?

I do not own one to give a testimonial, but by all other accounts, it works very well.

contact Mike Kossor (MKossor) through the forum. It's his product.

."... hand cranked tester would be the next level up then the HCCT for the top." Are there two devices that have hand cranks?

That is an easy one to answer .... spelling error - should have typed "E" not "H", sorry for that.,

Probably 4 main methods: 1) fully manual, 2) the 'buzz box', 3) HCCT (hand cranked) and 4) ECCT (electronic tester).

1. "...this type coil tester has no provision to see the time and space relationship of the coil spark output." Is quantum physics involved in the operation of the ignition system?

Probably quantum electronics is needed here somewhere. My beginners understanding is that this means the time the coil capacitor takes to charge and discharge with some relation to how many volts it can squeeze in.
I would guess that ideally you want all 4 coils to share the same/ similar characteristics there.
It probably makes a difference if coils are very badly matched or very poor performance, that may give a bit of rough running at high speed perhaps?

2. "... (allow) the car to start and maybe even run fairly well, but not optimally." A stock model T was built to be simple and cheap to produce. It was not designed to be a high performance car. On today's roads - level and smooth - reaching 35 to 40 mph with a stock car - is that optimally? And climbing a moderate grade in High Gear?

Yeah, well you may be right there. Certainly the better adjusted are the coils and carby the smoother the car would run.

There is the matter of cost. Spending about $350.00 (US) for an ECCT or about $1,000.00+ (US) for a HCCT. Is optimum performance worth this much for test equipment for four coils. Or is it the bragging rights of ownership? I can see a shop spending and owing such devices, but the average T owner?

I guess I missed the post that said the average T owner must personally own specialized adjusting equipment in order to end up with properly adjusted coils. Even our resident forum teen-ager has managed to find someone to befriend him and adjust his coils for him. He has shown a willingness to learn something new whilst being surrounded by some whose willingness to do the same is often sorely lacking.

If I lacked a hammer to drive a nail, and only had a rock, I would not spend time trying to convince the world that a rock is just as good as a hammer. I'd find someone with a hammer and either borrow it or hire the owner to use it for me. Maybe it's just me.

If you can own an ECCT for $350.00, that's a dollar a day for a year... 50 cents a day for two years, and so on. That's not much in today's money. It costs me more than 50 cents to mail a letter. If you drive your T much, having your coils in top condition could easily save you 50 cents a day in fuel.

Langs has coils at $60x4 equals $240 plus shipping. Thats approaching the $349 for the ECCT and you can adjust your own coils for the rest of your life. If you needed to do your coils a second time, the ECCT is less expensive than sending the coils off to be done and you dont have to wait for them to be shipped back. I will buy one

the ECCT website says they dont have any for sale

Send Mike an e-mail with your phone number and he will call you. He does work a full time job as an engineer, has kids, and it is Xmas so give him time to call. The website may be incorrect.

Scott_Conger wrote: ↑

Mon Dec 20, 2021 9:47 pm

If I lacked a hammer to drive a nail, and only had a rock, I would not spend time trying to convince the world that a rock is just as good as a hammer. I'd find someone with a hammer and either borrow it or hire the owner to use it for me. Maybe it's just me.

Or... use the rock to knock out the guy with a hammer. Then, take his hammer.

(Sorry.... )

We must move swiftly to enact much-needed rock buyback programs !!

Been Here Before wrote: ↑

Mon Dec 20, 2021 9:23 pm

There is the matter of cost. Spending about $350.00 (US) for an ECCT or about $1,000.00+ (US) for a HCCT. Is optimum performance worth this much for test equipment for four coils. Or is it the bragging rights of ownership? I can see a shop spending and owing such devices, but the average T owner?

If you are not prepared to do what is necessary to get & maintain a stock magneto/coli system (there is a lot of things that have to be right), Throw in the towel & get a distributor set up. A distributor is mostly trouble/maintenance free. You have your optimal ignition system @ a one time low cost.

If you purchase an ECCT or an HCCT, you will not only be able to maintain your own coils, but you will make a lot of friends when you do theirs as well. You also will never have to buy a 6 pack again.

DHort wrote: ↑

Tue Dec 21, 2021 6:22 pm

If you purchase an ECCT or an HCCT, you will not only be able to maintain your own coils, but you will make a lot of friends when you do theirs as well. You also will never have to buy a 6 pack again.

Great point! You could come out way ahead when factoring all the alcohol to the initial purchase.
Might get some fresh vegetables & a chicken also.

If you purchase an ECCT or an HCCT, you will not only be able to maintain your own coils, but you will make a lot of friends when you do theirs as well. You also will never have to buy a 6 pack again.

There is another thread (about the most viewed on the forum?) that describes how to make your own electronic coil tester with a bit of patience, a soldering iron and not that many bucks ...

Not all of us are of the ability to do that, but if there is a will for saving bucks, there is a way.....

The thread referred to by Adrian is indeed most interesting, even it's beyond most of us.

To me it shows that getting a device, usable by all, which measures and displays time-to-fire and other data is not straightforward, and is indirect praise for Mike Kossor for successfully developing and producing such a tool.

And on a wider note, the Strobospark seems to have been forgotten in some of the foregoing. It isn't quite as sophisticated as the ECCT, but it is much much better than any buzz-box, and adequate for most purposes. I have one and don't feel the need for an ECCT. But if had neither, I would choose the ECCT.

It all depends on what you attach to the buzz box. Oscilloscopes, ammeters, timing lights are some of what can be attached. There are other ways to tune coils for optimal settings. And some people like to tinker with this hobby. I have nothing against the ECCT, but I know that there are other ways of achieving the same results.
The ECCT and strobotach are easier but can be more costly.
I would like to get a set of ECCT coils but don't know anyone who has one. Don't know if Brent Mize will adjust without rebuilding them. Mine are all rebuilt with new capacitors.

Keep in mind that some people in this hobby might have tight budgets due to braces, broken arms, acne control, eye glasses, mortgages, house repairs, saving for childrens college, retirement savings, and student loans. I had all of these except for student loans. I didn't spend much on tuition. I no longer have a tight budget, just somewhat financially careful.

Art Mirtes

"I have nothing against the ECCT, but I know that there are other ways of achieving the same results."

Really? please share these other "ways"
Are these other ways theoretical or have you done them & tested the results?

You doubter/deniers simply need to drive your T's with your chosen tune method & compare the performance to a set of ECCT tuned coils. See for your self using a measurable method like GPS for speed or timed hill climb. You will likely, near guaranteed see a big difference.

There is the possibility that other aspects of your running condition are so also messed up that the change may be minor.

Speedy, Your post is spot on and Very True.

We're just lucky or unfortunate that the T will run and drive in such a deplorable condition and out of adjustment it's amazing. Probably the majority of the T's on the road could be improved with some simple adjustments but will continue for years poking along. That's why it's so neat and eye opening to ride along or get to drive another T that is well tuned and performing at it's best.

As stated earlier I am electricity challenged.

At the beginning of the life of the T, the company suggested that coils be adjusted using a HCCT, that is basically the Model T Magneto. Those that had limited access to a dealer with a HCCT would rely on some form of a buzz box tester with a 3 amp meter, mostly using a 6 volt battery.

One used AC voltage and the other DC voltage.

Ideally coils were to be set with the HCCT.

Later the buzz box was shunned and the ECCT is the instrument of choice.

Not being familiar with the ECCT, and one to be a doubter/denier of the device I would like to know at what voltage does the ECCT use to test and adjust the coils?

With the HCCT certain mechanical adjustment of the coil are necessary, and stress is placed on the cushion spring and its movement and clearance.
Are the same requirements considered with the ECCT?

Another question does a capacitor work the same with AC and DC voltages?

Also can you actually tell the difference between a HCCT coil and a ECCT coil? What are the measurable units?

A lot of information HERE:
www.modeltecct.com

Been Here Before wrote: ↑

Fri Dec 24, 2021 9:54 am

As stated earlier I am electricity challenged.

At the beginning of the life of the T, the company suggested that coils be adjusted using a HCCT, that is basically the Model T Magneto. Those that had limited access to a dealer with a HCCT would rely on some form of a buzz box tester with a 3 amp meter, mostly using a 6 volt battery.

One used AC voltage and the other DC voltage.

Ideally coils were to be set with the HCCT.

Later the buzz box was shunned and the ECCT is the instrument of choice.

Not being familiar with the ECCT, and one to be a doubter/denier of the device I would like to know at what voltage does the ECCT use to test and adjust the coils?

With the HCCT certain mechanical adjustment of the coil are necessary, and stress is placed on the cushion spring and its movement and clearance.
Are the same requirements considered with the ECCT?

Another question does a capacitor work the same with AC and DC voltages?

Also can you actually tell the difference between a HCCT coil and a ECCT coil? What are the measurable units?

Also electrically challenged. & running distributers on all my T's for over 30 years, but HCCT tuning coils for customers. I acquired a 14 & decided it should be run with a stock ignition. A 35 mph T is not for me. Not impressed & ready to try a distributor, I was convinced by a Montana friend that coils could be made to work well. Set up everything properly. HCCT coils ran ok, but not like a distributor. Performance was off.
Took the coils to a ECCT tune. picked up about 10 mph in top speed. That told me there there is a marked, measurable improvement. I dont know if a distributor would be an improvement @ this point, she runs too well to change now.

Do the research. Read/watch what the manufacturer has to say. Your question are all answered.

Speedy,
You asked what are the others ways to set coils besides a ECCT. As I previously mentioned, an oscilloscope or a timing light can be used. Current and dwell are important. The HCCT does not measure dwell, ECCT does.
The spark timing changes by 7.2 degrees with a change of 600 rpm crankshaft speed with a dwell of 2 milliseconds.This relationship can be used with the timing light. Must do the testing while running on battery.
Less than 2 ms is not good, 3 ms will work up to maybe 35 or 40 mph. The dwell from coil to coil must be as close as possible.
I prefer using my oscilloscope because it is simpler.

Where do I apply to for my free oscilloscope?

I have been trading emails with Mike K. trying to order an ECCT. He is having supply chain issues and it appears that it will be some months until he can ship one to me. I am looking forward to its arrival so I can check the performance of my cars with coils tuned with it. Bob Cascisa just rebuilt the meters for my two HCCT's that I am restoring (beautiful work, by the way) and I have had a Strobospark for quite a few years. I am thinking that if I tune the coils on the HCCT's then the Strobospark, and finally with the ECCT I may have a Model T that will run about 75 MPH. Merry Christmas all!

All this judgement of others methods and techniques, along with all of the soap-box preaching of this and that method, makes me happy to be running my Bosch Front Plate distributors. Who needs this....

BTW, Merry Christmas!

Pat,
Free oscilloscopes usually don't come with instructions, at least mine didn't. You will have to use your timing light.

David,
Do you have a strobospark. If so can you tell us if it determines dwell or anything else about it. Can anyone else tell us about them besides being harder to use than an ECCT. I don't know anyone who has a strobo.

Art Mirtes

Jerry VanOoteghem wrote: ↑

Fri Dec 24, 2021 12:44 pm

All this judgement of others methods and techniques, along with all of the soap-box preaching of this and that method, makes me happy to be running my Bosch Front Plate distributors. Who needs this....

BTW, Merry Christmas!

Right there with you. Bosch front plates. Most trouble/maintenance free. This has been the standard for the go fast/reliability guys forever. But the question was, could a T ignition perform as well. Montana guys prove it can. I am not converting my other T's from bosch front plates & 009's. My 14 will stay with the coil ignition. It works well now.
I am not proselytizing one way or the other, just passing along my experience. I dont care. If you are happy with a T that kinda runs ok @ 45 or less, fine.
Dont complain when others pass you up on the hills.

I could improve the performance of my T enormously by replacing the outdated, finicky T engine and transmission with the engine and transmission from my '14 Wildcat X. But I'm kind of partial to the way Ford did it, and anyway, the Wildcat would be a real dog with the T engine.

Art, I have had a strobospark for quite a few years. I started out thirty years age with a battery charger and an ammeter. I adjusted my coils to 1.3 amps and when they threw a good hot 1/4” spark I thought I had them near perfect. Problem was that I didn’t know how much I didn’t know, ignorance being bliss. When I got the strobospark I discovered that “all” of my coils had defective capacitors and most displayed the dreaded double spark. The Strobospark has the advantage over the Hcct in that it has a test mode for capacitor function and leakage as well as coil performance at three simulated mag outputs. It is not hard to use at all and and clearly displays double sparking. Hcct’s are new to me and the Ecct appears to be an improvement on the others. Keep in mind that I am only a tinkerer and not an engineer. My only claim to fame is that my friends refer to me as the worlds only “Certified JB welder”.

speedytinc wrote: ↑

Fri Dec 24, 2021 1:09 pm

Jerry VanOoteghem wrote: ↑

Fri Dec 24, 2021 12:44 pm

All this judgement of others methods and techniques, along with all of the soap-box preaching of this and that method, makes me happy to be running my Bosch Front Plate distributors. Who needs this....

BTW, Merry Christmas!

Right there with you.

If you are happy with a T that kinda runs ok @ 45 or less, fine.
Dont complain when others pass you up on the hills.

No, you really aren't...

Been Here Before wrote: ↑

Mon Dec 20, 2021 9:23 pm

There is the matter of cost. Spending about $350.00 (US) for an ECCT or about $1,000.00+ (US) for a HCCT. Is optimum performance worth this much for test equipment for four coils. Or is it the bragging rights of ownership? I can see a shop spending and owing such devices, but the average T owner?

Seem to recall that you had a HCCT in your collection.

"Seem to recall that you had a HCCT in your collection."Mark Gregush » Fri Dec 24, 2021 1:52 pm

Yes I do. And it is an interesting conversation piece on the shelf.

When it was given to me many years ago, acquired from a garage that had its roots in an early Ford dealership garage, I was told by the gentlemen trained as a Ford Mechanic (early Fords) it was always a conversation piece.

Free scope I got--- if the coils don't wack it out--- the coils made my snap on vantage cry, locked it up crying, is ok once I took battery out, rebooted it. The Allen smart scope has many functions, so far I got all the scope functions working that I have tried.
It has divisions using the width of the screen for 5 milliseconds, just have to get the car running to drive it to the scope.
Right now I am using engine without head and valves as " hand crank coil tester", I can keep up 80 rpm for about 30 seconds.
One of my coils makes 3 sparks, they all jump a .060 gap and seem equal in intensity---- what is the strategy to cure that?

3 sparks may be caused by the cushion spring being out of adjustment. Have you tried closing the spark gap to .030 to see if that eliminates the extra sparks? Getting a T coil to emit impressive sparks is usually not difficult, but that's not a satifactory method of adjusting them. I had no luck attempting to adjust by ear. Adjusting the point gap to minimize arcing at the points gave better results. Setting the coils with an ECCT gave excellent results. The engine runs much better, starts on Mag with the hand crank without difficulty, and the timer does not need daily attention. I still need to clean and dress or or replace the points. Running the engine with with the coils badly adjusted damaged the timer and likely damaged the points. I re-tested the coils after several hundred miles of driving, and they show to be holding the adjustments. I haven't messed with the (New Day)timer since I set the coils with the ECCT. It would benefit from a refurbishment. Time to fire on my set of coils varied several degrees before or after TDC. The spread in firing points between 2 of them was 8 degrees or more. It definitely affected engine operation.

David Kehle,
Thanks for posting the strobospark Information. I have stressed thr importance of checking the capacitor. Capacitor testers are available on the internet for maybe 20 dollars. I received one for Christmas about 4 years ago.
I am hoping for an impedance meter to measure Henries. This will determine if a coil has an internal short, etc.

I enjoy this forum because I learn a lot about model ts and about the character of some of the posters. I can take the beatings for my postings. I am not a graduate electrical engineer, but I have hung around with a lot of them.

Art Mirtes

If one is looking for extra testing equipment beyond the coil tester itself, the most important and probably only tool you need (beyond the obvious OHM meter with capacitance checker) is a Megger.

Anyone who has ever rebuilt a coil and found it to remain inoperative, didn't use a Megger, and if they had, they wouldn't have wasted their time doing the repair in the first place.

RE Scotts comment about the megger, I have known about using one for a while and started looking for one. Seeing a number of hand crank type and plug in type on eBay for fair prices. Guessing the plug in type would work better for me. Trying to turn the crank, hold the meter and read it all at the same time..LOL just don't think that will work too well for my eyes.

Does anyone know how to obtain a Strobospark coil tester ? I understand these were made by Fun Projects and they were bought out by Birdhaven which is now owned by Texas T parts. Are these still being made or do i have to find a used one for sale?

Regards
John Ernst
Edmonton, Alberta, Canada

Back in the day, the vast majority of Model T owners could not afford the special equipment needed to adjust spark coils. That is why they owned the cheapest automobile on the market. In 1970 when I bought my 1926 Model T coupe for my life savings of $600.00, I was a poor 16 year old student who was very new to Model T’s and was unaware that such equipment even existed, so, I adjusted my coils by ear like the old-timers did, until each buzz was uniform, steady and loud. In 1972 when I was concluding my 2 year restoration and I started my T for the first time, it ran like a sewing machine. Fifty years later, I don’t think my T has ever run as well as it did that first time, even with an extensive, professional overhaul and professionally adjusted coils which I had done 40 years later in 2010, when I could afford it. Jim Patrick

I have been beat up for suggesting anything other than an ECCT. They work well and easy to use but there other ways to set coils with good results.

The first feature to test is the capacitor. Most older coils that have not been repaired have a defective capacitor. A capacitor tester can be bought for 20 bucks or so. The big box stores don't carry them. Avaliable online

The points must be clean and pit free.

The current can be set with 3 d cell batteries and an ammeter. This takes a special type of ammeter.

The dwell setting is another story. The ECCTis the easiest way, but I use an oscilloscope because I have one. A timing light can be used to check variations in dwell from coil to coil.

The most affordable method is to use 2 d cell batteries in series and set the coil tension so that the points just vibrate. The resulting spark should jump a gap of .125 inch.
This will make your model t run, but not necessarily optimum. It will get you to the Ice Cream stand.

I will probably get beat up for suggesting this like I did last winter but that is ok.

Art Mirtes

An oscilloscope can be used for coil adjustment if you have one, know how to use it and have a way to periodically fire the the coil after resting like the timer does. Here is an example. It can be challenging keeping track of firing inconsistencies without a histogram display, infinite persistence may help if your oscilloscope has that feature.

https://m.facebook.com/groups/Fordmodel ... tid=4cl6lw

Interesting how the Model T ignition system is being brought into the future.

So the introduction of an oscilloscope is being discussed. Don't have an oscilloscope may be adapting (with the proper hardware) your computer may be the answer?

https://listoffreeware.com/best-free-os ... e-windows/

I am not suggesting that you use your computer or smart phone in this manner.

I am in the process of building a coil tester. It will not tell you if you have a double spark or some of the things an Ecct tester will but you can find out if you have a usable coil and will not empty your billfold.
Several years ago in Tinkering Tips one was pictured using a 6 volt battery. Ted Aschman said it would work better using a good electric train transformer as they put out AC current. Mine uses a small wooden box to hold the coil with original brass contacts, bolts and ceramic insulators. I made a grounded metal spark gap unit and had a model t amp meter wired in.
The first 2 coils I tested did nothing. The third one buzzed and put out a weak spark and the amp meter moved slightly. This set up should tell me if the capacitors are good or if the coils only need an adjustment.
Since then a 0 to 30 AC voltmeter and a 0 to 5 AC amp meter have been purchased. Right now I have about $12 involved as everything else were things that were in my parts and now I want to redo it on a different board and mount the new meters. I would like to redesign it so the unit will be in a wood box to keep it from dust and damage.
I liked the picture of the unit with a metal broom holder ho
Ding the spark plug.

The first thing to check on a coil that does not buzz is the points. As for capacitors, I believe a coil can both buzz and emit a spark with a bad capacitor, but it will not work correctly. Capacitors can be checked using a good analog ohm meter. A Model T ammeter or any other common dashboard type ammeter will not be accurate enough to give any meaningful reading of primary current draw. An adjustable spark gap is handy to have, and adjustment needs to be limited to 1/4" or less. It's not a good idea to operate a coil without a spark gap or spark plug attached. Using a transformer will indeed provide AC current at a steady 60 cycles per second. I believe that would roughly correspond to an engine speed of 240 RPM on magneto. The wave form would be different using a transformer. A transformer could be 6 to 12 volt and would need to be large enough to deliver 2 or more amps at 6 volts or more. A good train transformer or a big doorbell transformer could do that. It is impossible to accurately adjust coil dwell in a set of coils without a lot of patience or proper equipment. Variations in coil dwell in a set of coils can result in spark timing differences of 8 degrees or more between the cylinders, which will affect engine performance.