Spark voltage all comes from the primary voltage and the ratio of primary:secondary windings.

The ignition module is just a trigger (by breaking the coil ground and collapsing the primary field)

People can say whatever they want.
Electron theory is pretty much a given.

 

but (so they say) certain modules (HEI was designed for high volts)
can take the high energy some fry

soo..?

 

I really don't understand what you're trying to ask. ???

The two things I got from reading many pages about the old red modules was that they controlled dwell and therefore didn't use a resistor wire in the run circuit.

Once the coil is saturated that's all there is.

Full battery voltage will up spark voltage, (as when cranking) but what's the point of being able to open the plug gap if wires fail and you have to change plugs every 2 months because the electrodes are gone?

I read a whole bunch of other BS, like a DSII coil can't be mounted horizontally.
REALLY?
How come Ford mounted mine that way from the factory???

It's the internet and a LOT of $#!+ is spewed....
I'm sure I'm guilty too.

More to the point, what is possibly to gain from a relatively stock engine under 6,000 rpm?

It's like those who claim that running 110 octane race fuel is gaining them power.
... In a smogged up engine at 7.5:1CR and a stock timing curve.
LoL! No.
There's not enough compression to burn it effectively, not enough cam or ignition timing to take advantage of the additional octane.

We'll all have direct injection and laser ignition diodes soon enough.

 

In my next junkyard visit, I'm going to look for some DS boxes. I am going to reverse engineer them(hopefully) to see what the circuitry is.

I have searched through the Patent office and found some schematics for electronic ignition. Intresting reading there.

 

sorry I was thinking out loud


I just can't understand some ignition modules/coils use full 12v,and some
do not ,even though there isn't a "need" for it in stock applications

It seems a little funny how ford dropt volts for their Dura spark ii coils,but some duraspark I/III they used full 12,
, then again they use tfi E coil it upped to full power.

there is lots of experimenting going on even though they got it right then... oh lets do this....

 

It's not the input voltage, it is the input voltage factored by the coil's inductance and the ratio of primary to secondary windings.

http://en.wikipedia.org/wiki/Induction_coil
http://en.wikipedia.org/wiki/Ignition_coil
Ford changed coil designs multiple times.
Alluded to by my statement that my DSII coil is horizontal, and therefore epoxy, not oil, filled.

What they got right was a balance of cost, reliability and the technology of the day.
It is more than enough for a 1980-86 truck engine.
Would it meet 2013 emissions standards?
No.
But then again -NONE- of the truck would meet current highway standards.

F1 cars have pneumatic valves and very high tech ignition systems.
Would it help an old hunk of iron turning 5,000 rpm at 8:1 compression?
Not so much.
And the cost and complexity would be completely out of place on a vehicle like this.

Horses for courses...

 

I dare you to ask Numberdummy what he thinks about the reliability of the red grommet 'NeverSpark' system they had to deal with out there in California while he worked for Ford.

 

Sort of off topic but I just replaced the defunked transistor ign(and nla) on my 76 Sears riding lawn mower with a magnet on the flywheel and a detector from the lawn tractor pulling guys along with a 12v automotive coil of 3ohms. The thing starts better than it has in a long time. I was ready to junk the whole thing until I came across the thread on a lawn mower forum.

 

So you're using a hall effect trigger on your 37 year old Sears riding mower?
Cool!

That isn't so off topic.
It is very similar to how the DSII reluctor triggers the ignition module.
Except in our case the iron reluctor sweeps past the magnetic pickup.

 

This is a good question for Bill Vose. AKA 85Lebaront2
He owned a carburetor and ignition tune up shop for years.

I will say it has more to do with coil saturation and the ohms involved in a high ratio coil like the DSII.
You want the "hotter" spark a coil like this provides.

BUT
If you have too much dwell (saturation) the coil will heat up like any other filament.

Adding the resistor limits the current flowing into the coil.
You can see this by measuring the voltage at the coil connector.
First with the 'horseshoe' disconnected. (12V)
You have the full potential
And then with the coil connected (about 7.5-8V)
The coil load connected to ground shows how the electrons are throttled by the resistor.

The coil needs to build a magnetic field.
But once that is accomplished any excess energy will be converted to heat. (not good for the coil)

Ford engineers weren't stupid.
They got rid of the dwell controlling DSI modules and went with a simple resistor because they were much more robust.
They certainly knew a lot more than I do, but it's not rocket science.

 

A few years ago my ex-brother-inlaw and I got into a heated discussion of ignition systems. He had to buy a so called 100KV coil(cost $200~) to get a POS chevy running. I told him it is a waste of money but he countered the higher voltage WILL make a engine run better....

What get's me is most people don't understand is the POTENTIAL high voltage that a coil makes only starts the spark. When a spark jumps the gap its usually around 6K to 10K voltage, the higher potential voltage is converted into amperage to keep the spark going. Its all OHMs LAW at work. A higher ignition voltage does help out with higher compression engines and also with boosting too as the cylinder charge takes more voltage for the spark to jump the insulating properties of the charge mix. It's there to get the spark to jump the gap, the rest is all current that does the work ionizing the mix to start burning of the charge.

Back to the ex-brother inlaw, he wasted the $$$ and the car ran worse! Only after replacing a factory coil did the car run better along with two crossed spark plug wires too........and thats after he pulled the dizzy for some reason and got it 180 out of time......took me 5 min to figure out and fix after 2 weeks of him munging things up.

So factory ignition coils are good for stock applications, those "special" coils to me are a waste of money.

 

How's that 100,000V coil for vaporizing the spark plug electrodes and blowing holes in the plug wires insulation?

I'm sure it's fine for 8 seconds -1/4 mile at a time.


I=V/R

 

I did the same thing on a mower I had, could not see spending $130 for a coil for a 16hp oppy twin Briggs. I had the parts allready too, I found my schematic I drew up for it while scanning photos a few months ago. It did start and run better till the battery died as there was no charging system on that engine. Simple fix for that was a solar panel to charge up the battery while its not mowing! Hmm a solar powered lawn mower!

 

That's why that car ran worse, it made a intresting lighting storm under the hood even with "cheap" new spark plug wires. As I recall it was a racing coil too.

 

Hmmm,
Gasoline powered, solar ignited lawn mower.

We rarely had all these problems with magnetos and no battery.
And magnetos are STILL mandatory for piston powered aircraft and top fuel dragsters!

Why?
Because there is NO room for failure.