Plasma Ignition | Plasma Jet Ignition

[Willem Coetzee]

Hi.

I'm starting my project for plasma ignition to my Mazda RX-8. How would you suggest that I make the plasma circuit for this particular rotary engine? It has two chambers/rotors and a leading and trailing spark plugs, with an own coil for each plug. Has any of you done the plasma conversion for this kind of engine? What do you think, should I have plasma spark circuit for every four plugs or just leading/ just trailing plugs? Is the Street Fire MSD - type of cdi box that Aaron recommends in the book suitable with this kind of multi-coil original ignition?

I don't know if this is a stupid question, but are one cylinder motorcycle/scooter cdi boxes suitable for this purpose? They are waaay cheaper than multi-cylinder car cdi boxes.

Just trying to get a whole picture for this at the time...

Hi Mika,

Motorbike coils are not designed for how many times per revolution a rotary engine needs to fire per revolution.

Rotary engines fires THREE times per revolution per rotor. Each rotor is busy with all the 4-stroke stages, each stage separately at a different part of the rotor, per each revolution. The casing around the rotor separates each stage. Therefore you need only one spark plug (some rotary engines have 2) per rotor.

Standard Rx-8 ignition coils, just like any other OEM ignition coil, have to much impedance (or resistance if you like) to capacitive discharge.

But you now have 3 options:
(1) Just piggy-back a CDI with your spark plugs - it is known by many names, but it is just a CDI with an external addition of a set of HV-diodes per spark plug.
(2) Convert the whole ignition system to a CDI ignition setup including coils - then add an HV-diode set per coil.
(3) As per #2 above with the addition of the booster system of #1 that you can switch in and out as needed, and/or have cut in somehow in ratio to the amount of air drawn in as measured by the MAP sensor (variable resistor setup connected to the MAP).

Just like any other OEM system, you can take a 2-channel CDI (like the ones specified for wasted spark ignition) and piggy-back it on the spark plugs, at the spark plugs, with one channel per spark plug.

REGARDING OPTION #1:

If you look through this thread and read Aaron's 'Ignition Secrets' book, you will see that for each CDI channel, and therefore in your case, for each of your engines 2 spark plugs, you just need HV-diodes between the spark plug and one polarity of the CDI of one channel, and the other polarity output of that channel to ground (any engine nut not to far from the spark plug). Likewise for the other spark plug with the other channel of the CDI.

I'm sure MSD, Mallory or so, will a CDI for a RX-8, since rotary engine cars have been involved in racing and many more in street-racing for many decades now.

REGARDING OPTION #2:

Low-impedance, high output voltage, automotive ignition transformer coils (NOT the old "cylinder" type) are the best suited for capacitive discharge ignition application. With these transformer ignition coils you have another advantage: the HV output polarities can be identified - one (+) and one (-). HV (+) of one coil goes to one spark plug, and the HV (-) to ground, and the same with the other HV coil for the other spark plug. Then you just add an HV-diode set per coil.

I LEAVE OPTION 3 FOR YOUR DISCRETION.

DIODE ORIENTATION for Piggy-back CDI (first option) depends on your existing HV-output polarity...

if it fires (-), diode goes between spark plug and CDI (-) output, with diode arrow pointing TO cdi (-) output, and the CDI (+) output taken to ground. This is done for each spark plug each connected to it own CDI channel. This will prevent the HV hitting the CDI, and the moment the HV breaks-down in the gap there is a closed conductive loop between the CDI output terminal over the spark gap, with almost no resistance, through which the CDI will discharge.

if it fires (+), diode goes between spark plug and CDI (+) output, with diode arrow pointing TO spark plug, and the CDI (-) output taken to ground. This is done for each spark plug each connected to it own CDI channel. This will prevent the HV hitting the CDI, and the moment the HV breaks-down in the gap there is a closed conductive loop between the CDI output terminal over the spark gap, with almost no resistance, through which the CDI will discharge.

Option #1 does work, and has done so for many - I personally believe that the Murakami Ignition - Option #2 - can be more effecient.

ANOTHER ADVANTAGE YOU HAVE IS THAT YOU MIGHT ALREADY USE SURFACE DISCHARGE SPARK PLUGS - THEY PROVIDE BOTH SPARK GAP CAPACITIVE AND INDUCTIVE ADVANTAGES FOR PLASMA IGNITION, UNIQUE TO ONLY THE SURFACE DISCHARGE SPARK PLUGS.

But, spark plugs, no matter which plasma ignition you go for, and the spark plug wires, MUST be ZERO RESISTOR type!!!

[Willem Coetzee]

The reason "cylindrical" coils might short out, over-and-above winding orientation between primary and secondary coil windings, is also the phenomena Aaron has described of exploding wires.

These coils are not designed to handle current movement at even the speed of capacitive discharge, never mind RE or Aether.

But something that has always puzzled me since the beginning of interest in plasma is:

WHAT HAPPENS TO THE COMMON CONNECTION BETWEEN HV AND LV?

If the HV coil output is NEGATIVE, then surely the other end of that secondary is POSITIVE high voltage?

Then WHY is that REALLY put in common with the LV and connected to capacitor that is grounded on the engine block and the other side of the LV grounded in the OPPOSITE polarity on the battery through a RESISTOR?

I don't believe their theory that the reason it is like that is to achieve LRC "resonance"!

Is that not what is needed NOT to achieve Plasma Ignition as the normal standard type of ignition?

All jumping on the so called "resonance" gravy train, and then pointing to TESLA, do not all know what he means by RESONANCE - got nothing to do with the "cylinder coil" type resonance... it has to do with the SPEED OF AETHER AND ITS FREQUENCY OF PULSE UNIPOLAR TRAINS.

I don't say that resonance is not something important or not useful - for electronics it is important and very useful.

PLASMA IGNITION has to do with Unipolar Discharge, not "resonance"... so the moment you close-loop a system driven by a capacitor and coil through a resistor, you intend to make "electrons" do work, NOT Aether. Such a system is many order of magnitude to SLOW for Aether.

And there is no "motor" to spin in a spark gap - two polarities do not even necessarily make the most efficient motor.

The ONLY movement needed is for the air-fuel particle OUT of the spark gap into the cylinder space, in ONE direction.

A plain negative discharge robbed of "current" by resistance, through an engine's spark gap, is a most useless thing, which needs a unidirectional two-pole capacitive discharge on to of it at the minimum to improve its efficiency.

I also believe that the "radio interference" justification used to introduced more and more resistance, is a farce to cover up the fact that money put into system matterials are saved to get the high voltages.

I don't say that its bad to use resistance to achieve high voltage - you must be very clever to be able to so successfully have EVERYTHING working for so long needed NOT to get Aether energy or RE discharge in spark gaps.

So, then we through away the R of their LRC, not only on the LV side by not using the "balast resistor" and not using a "resonating capacitor", but also in the HV side.

So after al these designed non-RE parameters are abolished, the proof of what I suspect is SHORTED "cylinder" coils.

Its very true that you only need one unidirectional HV pulse in a spark gap for plasma ignition - but if it does not have the piggy-back booster added, and its pulse speed does not become fast enough... no plasma.

What I'm getting at is that these coils might be having a plasma party inside their casing, and a plasma explosion DOES happen, even being emerged in oil - the RE event never got OUT of their setup.

Can we blame the coil?

Not really, because it was part of a elaborate system designed NOT to allow plasma ignition.

Another thing is that if the coil managed a polarity flip on the secondary and it happens to be then pointing the correct polarity to the spark gap related to its primary connections an faze on the LV-HV common, the RE will have escaped into the gap, BEFORE it "internalized" and exploded any of the many internal connections.

[dowens]

Hi everyone, Doug here.

I noticed I seen people talking about waste spark. All my research says this, the waste spark system fires constantly during the 4 strokes for emissions, to burn off all fuel in all strokes,cleaner etc... While thats going on,, the waste spark, the injectors are doing the same thing, squirting fuel on the intake valve even while the valve is closed, then on intake stroke the valve opens and gets all the dumped fuel. The difference is the fueling systems between the two ignitions really IMO. Lower and high pressure fuel pumps, and different injector sizes and ratings etc..

On sequential or tuned port cars,and GDI(Direct Injection), the fuel gets injected on the intake stroke only (once),valve open and no other stroke, as well as the spark jumping the gap only once on it's tdc firing position.

The reason I posted this was if anyone else was thinking of using a cars fuel system to inject other fuels, or know what the injectors are doing if your experimenting. Good Luck

I'm also dabbling with a few tungsten spark plug designs that I hope to bring to the group soon.

[Charles Alban]

i have installed the plasma ignition system on my 96 Honda civic. since the honda has plugs deep set in the valve cover i used plug wires from aquapulser with long connectors and the diode wires attached. i'm using ngk non-resistor plugs with the electrode strap removed, the msd capacitor, an external accel high-performance coil and one microwave oven diode per plug. this set up certainly creates a fine big plasma at the plugs.

however, i find the diode wires are arcing against the valve cover causing misfiring. i tried wrapping them in insulating tape, but cannot get rid of the problem.

so i thought i'd try to take the diode wires off from the distributor end. this looks to be a good set up, and easy to do. but, it doesn't work. i can get no plasma spark. the set up is otherwise the same. it creates a normal weak spark with the diode disconnected, but as soon as the diode is connected, nothing. it makes no difference which way the diode is connected.

i've tried it several times with different plug wires...low resistance and regular, with the same result.

any ideas?

[dowens]

Charlea

Have you tried putting a plug back in the engine without the large gap to see if it stops the problem? Do you hve the long plugs from aquapulser that have the diode built in the plug end for the sparkplug? I would take apart the stock plug end on the wires that have the right boots, modify the old plug wires with new wiring from distributor.

i have installed the plasma ignition system on my 96 Honda civic. since the honda has plugs deep set in the valve cover i used plug wires from aquapulser with long connectors and the diode wires attached. i'm using ngk non-resistor plugs with the electrode strap removed, the msd capacitor, an external accel high-performance coil and one microwave oven diode per plug. this set up certainly creates a fine big plasma at the plugs.

however, i find the diode wires are arcing against the valve cover causing misfiring. i tried wrapping them in insulating tape, but cannot get rid of the problem.

so i thought i'd try to take the diode wires off from the distributor end. this looks to be a good set up, and easy to do. but, it doesn't work. i can get no plasma spark. the set up is otherwise the same. it creates a normal weak spark with the diode disconnected, but as soon as the diode is connected, nothing. it makes no difference which way the diode is connected.

i've tried it several times with different plug wires...low resistance and regular, with the same result.

any ideas?

[Mika]

Hi and thanks for suggestions... I already ordered a cheap 200w ac inverter, bridge rectifier, motor capacitors and power resistors for my plasma build. Does that sound like a deal to you?

It's a two rotor engine with two plugs/rotor, can it keep up with this one simple inverter? Do I need a cap for each plug or can I connect two plugs parallel in a same cap? I ordered two caps and hoped that's enough...

[Willem Coetzee]

Hi guys,

I didn't mean to drive the thread off-topic.

MIKA wants to setup plasma ignition in his Mazda RX-8 - these cars do not have cylinders, but TRIANGLE-shaped ROTORS, spinning in an off-center motion inside an OVAL-shaped ENCLOSURE.

Each of the 3 sides of a rotor in a rotary engine, SEQUENTIALLY goes through every cycle of the 4-cycle ignition method PER rotation.

This means that each of the 3 sides of a rotor, one after the other, will thus also go through ignition-and-combustion, one side at a time, PER revolution.

Most rotary engines have 2 or more rotors, out of faze with one another, i.e. rotor sides are not pared, so not one side of one rotor is fired at the same instant than one side of any other rotor.

And therefore, at the least, only ONE spark plug is needed per each rotor-enclosure unit, but can have 2 spark plugs per rotor.

The spark plug (or spark plug set) of a rotor has to fire every time one of the rotor sides passes it, since each flat side of a rotor compresses a volume of air-fuel that it took in, against the combustion space of the enclosure, in which the spark plug (or spark plug set) is situated, as the rotor turns, thus needing to fire into the combustion mixture of each rotor side as it passes through the combustion space...

That is WHY the spark plug or set per rotor has to fire 3 times per revolution - it is not randomly fired.

Coils designed for CYLINDER ENGINES only get to that number of charge-discharge firing per second at MUCH HIGHER revolutions near the END of their ABILITIES.

As the rotary engine revs up, they could soon become useless - the closest that would keep up would be a coil designed for 6 or 12 cylinder engine, and even then each rotor would need its own such coil.

And THAT might be EXACTLY the type of coil spec that might be used by manufacturers like MSD, or so, to work with their CDI units sold to owners of rotary engine vehicles.

A capacitor, or capacitor bank, known for its very fast discharge time, can also be charged very fast - it is only limited by efficiency of its design.

Therefore, Aaron highly recommends the "short-cut" of getting an off=the-shelve CDI unit.

The advantage regarding efficient CDI charging at high engine speeds should be obvious.

Regarding CDI DISCHARGE SPEED, you also should not worry with the Murakami Ignition Methode... Mark McKay has clocked the Peak HV Discharge Time of his own Murakami-system at TEN NANOSECONDS, and the LV at UNDER 100 MICRO SECONDS (if I remember correctly from the Gray Tube thread).

So the worry is not at the discharge time needed for even as short as needed in a rotary engine, but CHARGE UP ABILITY right up to the high revs.

Building a DIY CDI is advised so one can LEARN. And second hand and salvaged parts can be used and are very cheap. It will teach you HOW to get coil polarities and diode orientations right, how to make better spark plug connections, hoe to get better wire isolations, etc, etc, etc...

But nothing has to be "proved" anymore, so one CAN skip the practical learning stage, IF you understand the "theory" or "principals" correct and 100%.

For actual vehicle installation it then is HIGHLY recommended, whether one first demoed or jumped right in, to get a "shop cdi" that comes with the agent & manufacturer WARRANTIES and GUARANTEES of its abilities and endurance, etc...

[dowens]

Hi and thanks for suggestions... I already ordered a cheap 200w ac inverter, bridge rectifier, motor capacitors and power resistors for my plasma build. Does that sound like a deal to you?

It's a two rotor engine with two plugs/rotor, can it keep up with this one simple inverter? Do I need a cap for each plug or can I connect two plugs parallel in a same cap? I ordered two caps and hoped that's enough...

Mika, sounds right on the materials that are needed. Are you going to take pics and video once you get it working?

[Willem Coetzee]

... ordered a cheap 200w ac inverter, bridge rectifier, motor capacitors and power resistors for my plasma build.... I ordered two caps and hoped that's enough...

Hi Mika, you do need HV Ultra-Fast diodes too - maybe you forgot to mention that you do have it?

[dowens]

Yea William, I think the second plug is trailing for the exhaust on the rotoray,burning off fuel (emissions). Like it's scavenging the cylinder, like the waste spark in a regular 4 stroke motor does non-stop through out the 4 strokes.

[Charles Alban]

thnx dowens. yes. i plan to use the original stock boots now i've figured out how to take them apart and reassemble them. i'll use low resistance plug wires and connect the diode wire to the spark plug end through a hole drilled in the boot cap. hope that fixes the problem.

[dowens]

heres a link for diodes on ebay. 20kv 2 amps 10.88 for 2 isnt bad at all.
http://www.ebay.com/itm/321525013297...%3AMEBIDX%3AIT

[Mika]

I ordered 100 6a100 diodes for my build to have four 25 diode strings as Aaron suggested. One for each plug.

I'm not sure yet should I make the plasma spark only to the trailing plugs, since I've heard that rotary is very sensitive for knock. It does have a knock sensor though, I'm just not sure how much the stock ignition can and should be delayed using spark like this... I'm ordering granatelli 0 ohm wires too, so I should be able to make the hv dc contact to the coil side (?)

So does the high spark density of rotary engine make problems with diy plasma ignition system made with cheapo ac inverter? Its rev limiter is at 9500 rpm and with two rotors, it should ignite 6x9500= 57000 times/minute or 950 times/sec at that point. Is this possible with the diy setup I talked about? Should it have some special capacitors to keep up with the speed?

I might take videos, dunno yet.

[maxc]

I ordered 100 6a100 diodes for my build to have four 25 diode strings as Aaron suggested. One for each plug.

I'm not sure yet should I make the plasma spark only to the trailing plugs, since I've heard that rotary is very sensitive for knock. It does have a knock sensor though, I'm just not sure how much the stock ignition can and should be delayed using spark like this... I'm ordering granatelli 0 ohm wires too, so I should be able to make the hv dc contact to the coil side (?)

So does the high spark density of rotary engine make problems with diy plasma ignition system made with cheapo ac inverter? Its rev limiter is at 9500 rpm and with two rotors, it should ignite 6x9500= 57000 times/minute or 950 times/sec at that point. Is this possible with the diy setup I talked about? Should it have some special capacitors to keep up with the speed?

I might take videos, dunno yet.

Look up charge/joule/power calculator/ so you don't burn out converter. Use isolation transformer between inverter/ FWB.

[ThankyouBedini]

Spark gap.
Yesterday I changed my spark plugs. This time I did not remove the j-strap, but made the gap about 3 mm.
That gave me more power, and the engine was running much better, more responsive. The ignition timing is still TDC on the 1984 Land Cruiser with a straight six.