Pamcopete's electronic ignition

yamaman

Unfortunatly Pete, I couldn't find any info on polarity, or coke Very Happy

Here's the ones we need

pamcopete

yamaman

Now you're cooking! They are probably real expensive, so just buy one for the positive wire!

I'm not disputing what NGK says about their Iridium plugs. It's just that the negative polarity plug will perform better.

yamaman

Foud this, interesting:

www.ngksparkplugs.com/...0Plugs.pdf

Retiredgentleman

You are correct Pete, my old timing light does make contact with the spark plug lead. Time to retire the light to an automotive museum, and I'll likely buy one of those modern inductive types.

Great links on spark plugs, yamaman.

pamcopete · Last edited by pamcopete on April 10, 2009, 11:58 am; edited 1 time in total

yamaman

The link didn't work for me. No error message, just a blank screen.

RG

Well, at least it shows you have been messing with cars as long as I have! I had one of those back in the day. In fact, it was just a neon bulb! Had to wait for night time to be able to see it as I didn't have a garage.

Don't get an expensive inductive light. You won't need the preset advance feature of the realy exotic lights, and with the PAMCO, it will probably spend most of its time on the shelf.

pamcopete

yamaman wrote:

Ok, started answering my own question. So yes an irridum tip will definatly work better on one side with a single coil, than the other. This advantage would only be in regards to longevity though & not performance (at least thats how I'm seeing it).

The flame will still be better with irridiums than conventional types due to the minute size of the centre electrode.
The ground electrode will probably suffer a slightly premature death as it's made of a lesser material!

Interesting to note, NGK don't recommend altering the gap on their irridiums due to the danger of breaking the centre electrode!

www.ngkspark.com.au/sp...eature.php

yamaman,

This is essentially correct. I must not have read it properly when you first posted it. Too early in the morning....

yamaman

This is the page on the broken link:

yamaman

Excellent thread! I know I've learnt a bit!
Aside from funny readings off some timing lights Pete, is there another way to identify the polarity of the 2 plug leads?

So if I were to get 1 double iridium plug, where should I put it?

Cheers

pamcopete · Last edited by pamcopete on April 10, 2009, 2:31 pm; edited 1 time in total

yamaman,

Well, after you do the following procedure, you will know as much as I do about dual output coils!

You may need the assistance of a trusted person to do this.

1. Start and warm up the engine.
2. Shut down the engine.
3. Remove the spark plug cap from one of the wires.
4. Get a common lead (graphite) pencil, sharpened to a fine point.

This is where it gets interesting:

5. Hold the spark plug wire near the spark plug terminal, with the point of the lead pencil between the end of the wire and the spark plug terminal. Nothing is touching anything.
6. Have your trusted assistant start the engine.
7. With the engine running, observe the spark as it eminates from the wire to the pencil point and then to the plug terminal.
8. You will notice a straight spark from either the plug terminal or the wire to the pencil point and then a spray or shower of sparks from the pencil point to the opposite object.
9. The staright line is FROM the negative object, the spray or shower is TO the positive object.
10. So, the negative wire will have a straight spark from the wire to the pencil tip and a shower to the spark plug. The other wire is the positive wire.

The double Iridium plug will be installed in the positive wire.

You may want to use an insulated tool to hold the wire. Keep the wire in close proximity to the plug through out the test until your assistant shuts down the engine to avoid having the coil firing with one plug disconnected.

Test both wires as a sanity check. They should behave opposite to each other.

Do not contact the bike frame during the test. Test is best done before you have your first Fosters of the day. Drink lots of Fosters after to calm your nerves.

pamcopete

yamaman

Small edit to the pencil instrucitons. You need to actually remove the plug cap from the WIRE. I had said from the plug.

jimmythetrucker · Full Member Joined: Mar 12, 2008 Posts: 1283

yamaman, pete -- I read yamaman's NGK info post. I've read the last two pages of this thread. I have no doubt you guys are correct here, but I simply can't understand:

The negative battery cable is hooked to the frame. The frame is ground. The engine block is ground.

How, then, can a negative charge jump from the center electrode to ground? Or does it jump from ground to the center electrode?

Am I reading this right, and current now flows in BOTH directions in these new ignition systems? And if it does so, how can we still call it a DC system?

georelle

Jimmy
Current, the flow of electrons, is actually from negative to positive. So it will always be to the center electrode.

Georelle

yamaman

Well, I'm sure Pete will correct this if I'm mistaken.
The coil produces it's own complete electrical circuit, the polarity of the bike itself is not relevent.

To create a dual output coil, you need to send one output from each end of the windings, so they have to be from opposite poles!

A single output coil will throw out a negative charge down the plug lead, so the spark jumps from the small centre electrode to the larger ground electrode.

As a dual output coil needs to have one of each polarity, one plug fires as mentioned above, and the other fires from the ground electrode to the small centre electrode.

This is why on that side, it would be benificial to run the plug pictured at the top of this page. It would be of no benifit on the negative charged side!

At least thats my understanding of it! How did I go Pete?

pamcopete · Last edited by pamcopete on April 26, 2009, 11:17 am; edited 1 time in total

jimmythetrucker

Well, first of all, we all tend to think that current flows from the positive of the battery to the negative, but in fact, the electrons that make up the current actualy flow from the negative to the positive. It's one of the reasons why the British used to ground the positive terminal of the battery, because it was easier to think of the current flowing from the negative terminal in a wire to an electrical device and returning via ground.

The secondary of a dual output coil is not grounded. When the current in the primary winding collapses, like when the points open, or the transistor is turned off, the collapsing current induces a current in the secondary winding, so one wire from the secondary will be positive, the other negative, relative to each other, not to ground.

One secondary wire is connected to one plug, the other secondary wire is connected to the other plug, so the path for the secondary voltage is from the negative wire, to it's plug, across the gap from the tip to the ground electrode, through ground to the other plug, across that gap from the ground electrode to the tip, through the wire to the coil.

The fact that the plugs are grounded is incidental. You could connect the two plugs threads together off of the engine, ungrounded, and you would still get a spark across each gap.

So, the spark jumps from the tip to the ground electrode on the plug with the negative wire, and then jumps from the grounded electrode to the tip on the plug with the positive wire. So, the plug with the positive coil wire is where the problem lies. The tip of the spark plug is hotter than the grounded electrode. Electrons are "excited" by heat and they have a greater propensity to "jump" off a hot surface, so the plug with the negative wire from the coil has both a source of electrons and a hot surface, so the electrons will "jump" from the tip to the grounded electrode with a lower voltage, wheras, the plug with the positive tip does not have electrons "ready" to make the leap, so the higher temperature of the tip is no advantage.

The coil actually is an AC device. It is essentially a transformer that has a low voltage primary and a high voltage secondary, but it only works one pulse at a time instead of a continuos alternating current flow. Becasue the primary current never reverses, the secondary is always the same polarity.

The plug with the positive wire can take up to 40% higher voltage to jump the gap because of this phenomina with dual output coils, and that's the reason that dual output coils are always high performance "flame throwers". Most of the advantage to a "flame thrower" dual output coil goes towards ensuring that the positive plug fires under stress, especially a lean mixture, hence their advent in the post EPA lean mixture fuel delivery systems. So, coils such as Mikes new Green Monster coils are a good thing. The idea is to have such a high secondary voltage that the difference in voltage requirements between the positive and the negative plug doesn't matter any more.

pamcopete

yamaman

I was busy typing the previous post and didn't see yours, but, yes, you are correct.

That exotic plug pictured above was probaly developed just for this situation. It's smaller little "tip" on the grounded electrode would tend to get hotter and serve the same purpose as the center electrode tip, that is, it would induce those pesky electrons to jump the gap.

It also answers your earlier question about determining which plug is the positive or negative, that plug would work with either polarity, so you wouldn't have to get a volunteer to hold the pencil on the spark plug with the engine running!!

(By the way.....I've been involved with computers since before most of you were born, and I still do some programming under contract, so I'm not stupid, but........were the hell is the spell checker?)

jimmythetrucker · Full Member Joined: Mar 12, 2008 Posts: 1283

pamcopete wrote:

jimmythetrucker

Well, first of all, we all tend to think that current flows from the positive of the battery to the negative, but in fact, the electrons that make up the current actualy flow from the negative to the positive. It's one of the reasons why the British used to ground the positive terminal of the battery, because it was easier to think of the current flowing from the negative terminal in a wire to an electrical device and returning via ground.

Jimmy sez -- That much I always knew. I always figured ground was ground. You could wire the battery onto the car either way (A lot of cars came from the factory wired positive ground. A lot of trucks did, too. I actually drove one for a year.), the lights will work either way. The only things you have a problem with are motors -- starter motors, heater motors, wiper motors, etc. and generators/alternators -- which have to be wound accordingly. I'm not sure about the regulator, probably have to change that, too.

pamcopete wrote:

The secondary of a dual output coil is not grounded. When the current in the primary winding collapses, like when the points open, or the transistor is turned off, the collapsing current induces a current in the secondary winding, so one wire from the secondary will be positive, the other negative, relative to each other, not to ground.

One secondary wire is connected to one plug, the other secondary wire is connected to the other plug, so the path for the secondary voltage is from the negative wire, to it's plug, across the gap from the tip to the ground electrode, through ground to the other plug, across that gap from the ground electrode to the tip, through the wire to the coil.

The fact that the plugs are grounded is incidental. You could connect the two plugs threads together off of the engine, ungrounded, and you would still get a spark across each gap.

So, the spark jumps from the tip to the ground electrode on the plug with the negative wire, and then jumps from the grounded electrode to the tip on the plug with the positive wire. So, the plug with the positive coil wire is where the problem lies. The tip of the spark plug is hotter than the grounded electrode. Electrons are "excited" by heat and they have a greater propensity to "jump" off a hot surface, so the plug with the negative wire from the coil has both a source of electrons and a hot surface, so the electrons will "jump" from the tip to the grounded electrode with a lower voltage, wheras, the plug with the positive tip does not have electrons "ready" to make the leap, so the higher temperature of the tip is no advantage.

Jimmy sez -- that's big news to me. I been away from the car shops for thirty years and haven't kept up with all the changes. It's the part where the secondary winding actually makes a circuit -- through ground and back to itself -- that blew my mind. In my 'old' world, everything went from the battery to ground and back to the battery. My idea was that when the spark arced to ground, that spark was history.

pamcopete wrote:

The coil actually is an AC device. It is essentially a transformer that has a low voltage primary and a high voltage secondary, but it only works one pulse at a time instead of a continuos alternating current flow. Becasue the primary current never reverses, the secondary is always the same polarity.

Jimmy sez -- Uh huh. The coil is just a step-up transformer. Wire it into an AC circuit, that's how it would perform.

pamcopete wrote:

The plug with the positive wire can take up to 40% higher voltage to jump the gap because of this phenomina with dual output coils, and that's the reason that dual output coils are always high performance "flame throwers". Most of the advantage to a "flame thrower" dual output coil goes towards ensuring that the positive plug fires under stress, especially a lean mixture, hence their advent in the post EPA lean mixture fuel delivery systems. So, coils such as Mikes new Green Monster coils are a good thing. The idea is to have such a high secondary voltage that the difference in voltage requirements between the positive and the negative plug doesn't matter any more.

Jimmy sez -- So if I wire one of your newfangled ignitions onto my bike with one of Mike's new, yellow, dual-output coils, does that mean I HAVE to go to Iridium plugs? Or can I still use my good ol' NGK BP7ES?

yamaman

You can run standard plugs, no problem. Thats why the coils are hot rodded, they compensate for the wrong polarity!

The 2 pics show different iridium plugs.
Should you want to run iridium's then with 2 single coils, the one that looks like a normal plug are perfect.

With a dual output coil, the freaky looking one with 2 tips should be used at least on the positive charged plug lead. Probably save confusion by running 2 of these!

This is only to get the absolute maximum benifit out of these plugs!

jimmythetrucker · Full Member Joined: Mar 12, 2008 Posts: 1283

Thanks fellers. That was most enlightening.

650skull · Support Staff Joined: Jul 19, 2007 Posts: 1186

I installed a dual lobe cam with a single set of points using the dual output coil part no 17- 6822.........Are you saying i should be running the iridium ground electrode with 2 tips ? ......... i am using the ones off mikes and they are the ones with the nickel ground electrode

yamaman

Well, on the positive charged plug lead, the spark is trying to jump from the massive ground electrode to the tiny centre electrode.
This is not at all efficient and while it will still work ok, to get the full benefit of the iridium plugs, then yes you need at least 1 of the fruity 2 tips!

650skull · Support Staff Joined: Jul 19, 2007 Posts: 1186

Thanks.......should give mikes a heads up if he is selling the wrong plugs for the dual output coil, considering all of the electronic ignitions that are around

yamaman

I'm not sure on availability of these plugs yet?

If you go back through this thread, you'll find the Autolite one Pamcopete used!

650skull · Support Staff Joined: Jul 19, 2007 Posts: 1186

Looks like the iridium ground electrode is a lot longer...........would that cause any problems........................yamaman- [Quote]This advantage would only be in regards to longevity though & not performance (at least thats how I'm seeing it).[quote]
yamaman-[quote] Well, on the positive charged plug lead, the spark is trying to jump from the massive ground electrode to the tiny centre electrode.
This is not at all efficient and while it will still work ok, to get the full benefit of the iridium plugs, then yes you need at least 1 of the fruity 2 tips![quote].................... Which is it ?

yamaman

G'day Skull, almost everything I know about this subject, is written on these pages and the links from them! So I'm certainly no guru on exotic plugs.

So in saying that the best plugs for dual output coils are the twin electrode type, thats how the facts present themselves here.

I would think that the absolute ultimate combo would be a nickel ground electrode/iridium centre electrode plug on the negative charged coil output. And a conventionaly sized nickel centre electrode/iridium ground electrode on the positive coil output!

Thats what Ford had for their engines, + & - plugs, Autolite then made ambidexrous plugs so you could buy 8 same plugs instead of 4+ & 4-

So yes, the conventional type plug (iridium or otherwise) is going to wear prematurely at the ground electrode on the positive output side!

Also on that side, the spark will be less efficient, as it is "running backwards".

As I said earlier, all this is just in the name of aiming for the highest possible standard, 2 standard NGK's are going to work fine, it's just if your going to upgrade to the iridium, then to get what you should expect to achieve from them, at least the positive side should be a fruity 2 tip!

Cheers

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