--






 Can you lay out a simple schematic of the ADIS-4 firing two separate
 coils?
 One for the front rotor and one for the rear rotor.
 I was thinking the ADIS-4 #10 pin fired one coil and the front rotor and
 the #12 pin firing the other coil for the rear rotor, I am confused bythe
 12 volt power supply wire, through the #8 pin, going directly to the dual
 coils.
 I am using a separate ADIS for the trailing plugs and all four coils that
 came with the Renesis engine so I won't have a wasted spark.

 --
 Karibian

 A 4 cyl EDIS won't work IMHO.
 It uses two waste spark coil packs to handle four spark plugs.
 Using a waste spark on the trailing plugs is not allowed
 so you are one coil short.

 An 8 cylinder EDIS system on the other hand uses four waste spark
 coil packs (four single coils) So you can use two stand alone coils
 for the the trailing plugs and one waste coil pack for the leading
 plugs I think but I would check it on a bench test set up before I
 put it on a rotary engine. It is also possible to use four stand
 alone coils with the 8 cylinder version which is what I recommend.

 Which EDIS system do you have? You will also have to find
 a Ford EDIS trigger wheel.
 http://www.megamanual.com/ms2/36-1.htm

 This pdf covers the whole thing for a piston engine.

 Paul Lamar

 Paul, The EDIS 8 fires every 90 degrees of shaft rotation so only half
the
 outputs are usable on an engine firing at 180 degree intervals. The hall
 effect sensor is mounted about 52 degees befor the ignition point and if
 hooked up to the EEC 4 or 5 computer backs up the timing for advance.
 Without an input from an EEC 4 the coils fire 52 degrees of teeth on the
 trigger wheel from where the hall effect sensor is mounted. If I
 understand Karibian in his post he wants to use two EDIS 4 modules each
 firing two plugs at 180 degree intervals. If there are two hall effect
 sensors 180 degrees apart around the trigger wheel (18 teeth) each firing
 an
 EDIS module there are four independant sparks at 180 degrees. If the
second
 Hall effect is retarded 1 tooth it will fire the trailing plugs 10 degrees
 different than the leading plugs. Leaving the 18 tooth separation and
 firing
 leading and trailing plugs at the same rotation provides a completely
 redundant ignition system.
 The EDIS is a waste spark system meaning that the spark energy goes
 to the cylinder with least pressure fires that plug goes thru the engine
 block and fires the second plug on the circuit back to the coil. If only
 one plug is connected to the coil pack a path to complete the circuit brom
 the block back to the other terminal on the waste spark coil must be
 provided.Firing only one plug will dramatically increase dwell on the
plug.
 The EDIS and Hall effect sensor are really light, inexpensive even if
 new parts are used so using two of them doesn't seem to be a problem. The
 parts are encapsulated in a plastic block so moisture, vibration, and low
 air density should not effect their reliability. Using two 4 cylinder coil
 packs does add weight but until someone weighs two of them as comparedto
 four single plug coils the difference in weight is unknown. Using the 4
 tower coil packs that came with the EDIS would match the electrical
 resistance and inductance of the EDIS and coilpacks as Ford designed them
 and would be expected to be as reliable as the car ignition. My piece of
 mind is worth a few ounce weight penalty using the waste spark coils. The
 coil pack is actually only two coils molded together with a tower
 connection
 of both ends of each of the two coils for a total of four plug
connections.
 Two coilpacks is a total of four coils just like four individual coils
just
 less mounting brackets to fabricate.

 george grimes

 I was afraid of something like that. Do you have a chart of
 a Ford V8 showing when each cylinder fires as a function of
 the crank angle? I have the firing order. Is the Ford a single
 plane crank or 90 degree crank? Must be a 90 degree crank if
 it fires every 90 degrees. Too bad I thought I was on to something.

 I guess you will need two 4 cylinder EDIS. With a little
 fooling around I think I can get one CAS to fire two
 units. Those are mag sensors and not Hall Effect.
 Hall effect require rotating magnets. Ford calls them
 "Variable Reluctance".

 I would not use the waste spark coil pack on the leading
 plugs with just one plug. I am not sure
 why. Have you tried it with out a spark plug load?
 I dimly remember from way in the past that could be
 a no no. Perhaps it arcs over inside the tower.

 Paul Lamar

Paul, It fires an EDIS 8 every 90 degrees just like when it had a
distributor cap. It fires one coil pack every 9 teeth on a 36 tooth wheel.
Using the waste spark coils fires the 4 cylinders on the second revolution
using the same four outputs. Using a 27 tooth wheel with an EDIS 8 there
would be three outputs 120 degrees apart (still counting 9 teeth) and the
missing tooth would reset the count not firing the fourth output'. I
haven't
tested this three rotor idea but IMHO that is how it works based on two
weeks of Internet research.
 Personally for the return circuit back to the waste spark coil I
suspect a resistor would be required in series with the plug lead. I am
intending to just screw some extra spark plugs into a block of aluminum
bolted to the block which won't fire anything just provide the electrical
load. For the four rotor there is a small pad on the connector bell housing
between the engine sections thick enough to screw the plugs into which was
necessitated to be able to remove the pattern from the casting sand
 You are right they are actually variable reluctance coils not Hall
effect. I am going with two of them so that I can fire the plugs separated
by a few degrees of E-shaft rotation and to make each half of the ignition
completely independent. This is also a multi-spark ignition at the lower
RPM
of the car engine but resorts to single spark at high RPM with an upper
continuous RPM of 8000 RPM
 With no moving parts and the reliability and price of well developed
mass production parts I just don't see any downside to this stand alone
ignition. Ford liked it enough to build 12 million of them before
incorporating it into the engine computer.

george grimes

Upload a schematic for Hurant.

Paul Lamar

George...

I am not certain that the current path you described above is correct. I
have always read that the wasted spark was really not a full spark due to
the much lower pressure and conductivity of the combustion atmosphere
compared to the cylinder that is loaded with fuel and air. The current is
simply looking for the least resistant path, and the charged cylinder is it.
Therefor, of the two possible outlets of each coil, the one with the lowest
resistance at the point of arc, releases the load.

Correct me if I am wrong

Ed Carver

Here is the way I think it works.

Air is an insulator. Higher pressure better insulator.
Higher resistance. High altitude magneto's must be
pressurized.

Power = voltage times current. The waste spark is looking
at a comparatively low pressure low resistance chamber. Almost a short.
There is no voltage across a short. So no power is dissipated but
the spark jumps easily.

So the compressed mixture gets most of the spark POWER.

One might try grounding the un used spark tower.

Paul Lamar Leesburg VA


Paul, The post above is correct with one minor exception. The waste
spark is not seeing atmospheric pressure because it is firing into the
nearly completed exhaust stroke where there should be slightly less than
atmospheric pressure due to scavenging and an elevated temperature of the
gasses. The lost spark systems are firing two plugs in series and it istrue
as posted above that the lower pressure on the exhaust plug takes less
energy to fire than the one under compression. Therefore most of the joules
are expended at the plug under compression.
 A coil on plug system works like a conventional single coil ignition
with the case of the coil grounded through it's mounting bolts and mustbe
electrically connected to the engine block to complete the circuit Boththe
coil on plug and waste spark systems require that the end points of the
high voltage windings of the coil be connected together. If not connected
there is no current flow on the secondary side of the coil. The difference
is that on the coil on plug system one spark plug is in series with theends
of the coil winding and with waste spark there are two in series.

 The original post by Karibian asked if he could put one plug of
a coil pack on the leading plug and a lead from the second coil from that
coilpack on the trailing plug. That won't work because they are fired by the
EDIS controller 180 degrees later and you would have one of the plugs on a
rotor firing into the exhaust on that rotor. The correct way is to put one
coil lead on the rotor 1 leading plug and the other coil lead from that
coil pack on the leading plug of rotor2. A second EDIS and coil pack would
be used on the trailing plugs, one coil to rotor 1 and the other to coil 2.
If you are using the multistrike ignition Paul is developing for the leading
plugs you can do the trailing plugs with EDIS as described above.
 I have a THEORY which I will be testing about firing the trailing
plugs later in the rotation. From a mechanical standpoint if there is a
slight pressure variation (increased) at the area of combustion that may try
to torque the rotor around it's center bearing with the torque being
leveraged by the stationary gear. In looking at a picture of the engine that
would appear to alter the effective stroke instantaneously thereby
increasing torque for a few microseconds.My intent is to have both of the
variable reluctance sensors independently in flight adjustable to set
timing for maximum cruise RPM. Possibly someone who knows the history of
how Mazda has timed the ignition on their rotary engines. I saw somewhereon
a link from craigs rotary page that Mazda had a racing variant with three
plugs per rotor on a quad rotor engine but no mention of ignition timing.

george grimes

OK If you wanted to run one of the 4 cylinder packs why couldn't you use it to run a single rotor firing both leading and trailing plugs from the same coil (usually 1 and 4 are paired and 2 and 3 are paired.) You wouldn't have a 2 coil redundant system but even if you had a coil failure yu would only lose 1 rotor. The typical 4 cylinder has a flat crank and the waste spark is on the exhaust stroke for the paired cylinder. On the 2-rotor we need a spark at 180° intervals, alternating between rotors, so a 4 cylinder pack should work fine. Unless I missed something. If the arguement is that you need true redundancy on the 4 cylinder pack you could use 2 with one wire of each of the coil pairs grounded. The coils are almost always made with a floating secondary so as long as you used 1 wire from 1-4 and 1 wire from 2-3 withthe other grounded it should be fine for one plug (either leading or trailing) for each rotor. That is unless Ford did something completely different inside of these modules. Normally the floating secondary causes one of the pair of plugs to fire backward, which causes higher plug wear. switching between the two wires to check wear and getting the wire that causes the plug to fire normally from the center electrode to the sidewire is best. Also don't run the fine wire center electrode plugs with the waste-spark system because the one firing backward erodes quickly.
Bill Jepson