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 by the
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 compared to
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