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Ford edis with megajolt

Frank from Quebec

I'm New Here
Hi guys,

Not specific to RV's but looking on the net your group is clearly the most active about the subject !!

I am rebuilding an aircraft with a Continental O-300 6 cylinder engine and will be using dual Ford edis system managed by 2 programable Megajolt boxes.

I have not found much about people using this system on aircraft but it sure make sense to me !!

You have a 10 x 10 window of RPM and load to play with and the possibility to have 2 different map swithable on the fly.

Here is the link to the maker: https://www.autosportlabs.net/MegaJolt_Lite_Jr.

And a picture of my ignition map while running the whole system spinning the trigger wheel with and holding the sensor in the toolpost on my lathe:


It seems to be very accurate with a timing light on the chuck and very tolerant to sensor to Wheel clearance, up to 1/4 inch no problem and no shift in timing.

Hope you like it and open to comments :)

Frank
 
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Welcome to VAF!

Frank, welcome aboard the good ship VAF:D

The Ford/Megajolt thing is very promising, looking forward to seeing your setup.
 
We're flying two EDIS systems locally, on an RV-8 and a Mustang II.

The Mustang's parallel valve 360 is triggered with a toothed wheel behind the ring gear, and the standard Ford sensor. I'm running an IO-390 with a mag hole trigger based on an ND reluctor, which is conceptually similar to an Electroair trigger. Both aircraft retain one magneto for now, a conservative approach to testing a new ignition system, but so far it looks like both of us will go dual eventually...already built/bought the needed parts. There are a few others following along.

A very complete EDIS/Megajolt article can be found in the British LAA magazine, August 2011. Author's name is Steve Brown. Steve apparently did quite a lot of bench testing per English homebuilding rules. I'll write something for Kitplanes in due course.

Reluctor-based systems are old tech, but work fine. Ford sold millions of EDIS ignitions worldwide, in 4, 6, and 8 cylinder versions. The Motorcraft ignition module is considered very reliable, and will continue to operate independently, delivering spark at 10 BTDC if the timing control computer is dead. The EDIS module can be mounted on the hot side of the firewall. However, it's just as easy to put it inside the airplane, with the Megajolt control computer, where it can live a life of luxury. In that case, there are no electronics mounted firewall forward, just the pickups (a magnet and some wire) and the coils (iron and some wire).

A late model Ford EDIS coil pack will look extremely familiar to P-mag owners. I elected to use an earlier style, just because it incorporates positive terminal retention.

I've discussed aircraft use with Brent Picasso at Autosport, who produces the little Megajolt controller. Brent is ok with experimental use, as long as everyone understands the controller was not designed or intended specifically for aircraft. The intended use is converting points-equipped fun cars to EI.

The components, leveraged as they are from automotive production numbers, are downright cheap when priced in AMU's (Aircraft Monetary Units). One of our intrepid VAF'ers bought all the Ford components for two complete ignitions at the local wrecking yard; the bill was $60. You can also buy everything new if you wish, from the usual auto parts sources. Autosport's Megajolt control units are currently $169 each, but Brent has been known to put them on sale. You'll need a laptop for setup. The software is dirt simple.

I had not intended to say much here until flying 50 hours or so; right now (note: March 2016) I'm at about 10. So, no concrete endorsement yet, although the system is working well. If you want to know more, start by downloading the Megajolt installation and operating files at:

https://www.autosportlabs.com/product-category/megajolt-ignition/

Like everything else in EAB these days, some builders will prefer to buy a complete kit with detailed instructions, while others will happily build whatever they want. I don't expect EDIS installations to put a dent in sales at SDS, Lightspeed, or Electroair, but it certainly appears to be a viable alternative for the DIY-minded.

I built accessory case trigger assemblies:

Finished%20Triggers%201000w.jpg


Trigger%20Installed.jpg


Motorcraft EDIS modules (black), Autosport Labs Megajolt/E timing controls (silver):

Controllers%20and%20EDIS%20modules.jpg


Wiring:

Wiring%20-%20IGN1.jpg
 
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YAY!
I'd been looking into that too.
I'll admit, I went Pmag for quick results when a mag went bad, but I'm still interested.
 
Just doing a little background research on the web, and MegaSquirt keeps coming up.

What the difference between MegaSquirt and MegaJolt?

Thanks,
 
Just doing a little background research on the web, and MegaSquirt keeps coming up. What the difference between MegaSquirt and MegaJolt?

Simple answer: Same family tree, different branches. MegaSquirt started as an open source DIY fuel injection for everyone. At some point ignition control entered the picture as a Megasquirt function, then branched into the idea of a simple "ignition only" controller. Ultimately Autosport's principals put such a unit into production, currently known as the Megajolt/E.

Plenty of good EDIS information can be found on various Megasquirt websites (and some bad; this is, after all, the web). Be aware that Megasquirt will run a variety of different ignition schemes in addition to EDIS, as well as fuel injection.

Autosport's Megajolt/E is EDIS only.

BTW, before someone asks, no, I am not going into the ignition business. Regular readers know I do support all kinds of DIY efforts, as long as it doesn't compromise safety. Here I think the hardware/software is robust enough to fly, so the wild cards are (1) fabrication skill, and (2) installation details like wire routing, connector selection, and software settings. If you have the skills, go for it. If you don't, there is no shame in buying a CPI kit from Ross at SDS: http://www.sdsefi.com/cpi.htm
 
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Like It

I changed out my bottom plugs to NGK about 30 hrs ago by auto boots on Slick harness and running a .025 gap and its running great.I was was looking for a simple way to build a electronic ignition that was cheap and dependable I think this is it. Thank you Dan its like I told you a couple years ago at Thomasville Fly-In your a legend in your on time.Dan could we see a picture of the gear mounted on crank?
Thanks Bob
 
Bob, almost anything which provides 35 teeth and a skipped tooth space will work. The Lycoming flywheel has 12 AN4-sized mount points, so for a first pass, I drew this, and Kirk (that's Kirk Harrel, the Mustang II owner) turned it out on his mill. It's a steel plate, 3/16" thick IIRC, cut on a rotary table. It would be real easy to do on a waterjet; hand the operator a .dwg file and a few bucks. Flywheel = gray, trigger wheel = white. A standard Ford pickup points forward (at the sides of the teeth), much like the mount you've seen for hall effect triggers. Note small alternator pulley.

Wheel.JPG


BTW, a little design tweaking would save weight, but for those who have rear CG concerns, well....

On Kirk's Mustang II:

Kirks%20Wheel.jpg


Make the tooth width the same as the width of the tip of the pickup; that nets a clean sine wave signal for the EDIS module. See the blip on the right? That's the passage of the skipped tooth.

Waveform.jpg
 
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Lest anyone think the basic tech is unknown in airplanes, this is a Electroair mag hole trigger...60 teeth less 1, tubular magnetic pickup on left, which can be used with a 36-1 wheel also. It will be same output waveform as in the previous photos, and Electroair sells them in two sizes. Me? I like the ND pickups, reliable and very compact.

Reluctor%20800W.jpg
 
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Dan;
I see 36-1 trigger wheels of different diameters for sale on fleabay, intended for the Megajolt market.
What is the diameter of the inside of the Electroair mag hole housing?
This looks like a cost effective and quick timing solution.
 
For what it's worth, the Ford Explorer 5.0 (aka 302) V-8 from 1996 to 2001 used EDIS, and had a 36-1 wheel on the harmonic balancer. Probably too small for a Lycoming flywheel though I haven't tried to measure. My experience is from automotive projects using Ford's EEC-IV EDIS.
 
Dan;
I see 36-1 trigger wheels of different diameters for sale on fleabay, intended for the Megajolt market.
What is the diameter of the inside of the Electroair mag hole housing?
This looks like a cost effective and quick timing solution.

Not much on Ebay is going to fit the Electroair shaft. The easy way to adapt one to EDIS would be to simply re-machine the existing wheel, which is really a disk about 1/8" thick. Lop off the 59 teeth, cut 35, and slide the pickup inboard a wee bit.

The disk is clamped to the end of the shaft with one allen screw and Loctite. There is a tiny roll pin under the cap to safety rotation, but I'm not real impressed. The pickup just clamps in place with set screws.
 
Wow !!! more than a thousand view and 15 answers !!! In a single day !!

You guys rock !!

I'm happy to read that some you tried it and it worked and I am also very happy to see that none of the 1000 viewers thought I was crazy :)

Thae rest of my aircraft will not be ready to fly for a few months still but the system is debugged on the bench and ready to mount on the motor.

I will share the results with you first, and maybe one day get my act together and build a RV8 :)
 
Simple answer: Same family tree, different branches. MegaSquirt started as an open source DIY fuel injection for everyone. At some point ignition control entered the picture as a Megasquirt function, then branched into the idea of a simple "ignition only" controller. Ultimately Autosport's principals put such a unit into production, currently known as the Megajolt/E.

Plenty of good EDIS information can be found on various Megasquirt websites (and some bad; this is, after all, the web). Be aware that Megasquirt will run a variety of different ignition schemes in addition to EDIS, as well as fuel injection.

Autosport's Megajolt/E is EDIS only.

BTW, before someone asks, no, I am not going into the ignition business. Regular readers know I do support all kinds of DIY efforts, as long as it doesn't compromise safety. Here I think the hardware/software is robust enough to fly, so the wild cards are (1) fabrication skill, and (2) installation details like wire routing, connector selection, and software settings. If you have the skills, go for it. If you don't, there is no shame in buying a CPI kit from Ross at SDS: http://www.sdsefi.com/cpi.htm

I have built a Megasquirt based EI and just started installing it on my 320 now that the weather has improved. I didn't realize the Megajolt was out there or may have used it. However, the Megasquirt supports simpler and cheaper coil setups and more flexibility across all components in the system. I am using a nice wasted spark coil pack. Another benefit of MS is that I don't need coil drivers. You can add high current ignition drivers directly on the circuit board. It will also handle fuel injection and it's possible I will experiment with that in the future. Also, I was very familiar with it, as I put one on my old Porsche when I added the turbo (I needed an ability to customize the tune and don't have the skills to burn chips on the old Bosch units). I used a hall effect sensor (MS supports either hall effect or VR) with 3 magnets (4-1 wheel), as that was easiest to fabricate/adapt into an old mag carcass.

Dan, did you make those nice Pick-up units? Any interest in making me a set:) I don't have a lathe.

Larry
 
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Bob, almost anything that provides 35 teeth and a skipped tooth space will work. The Lycoming flywheel has 12 AN4-sized mount points, so for a first pass, I drew this, and Kirk (that's Kirk Harrel, the Mustang II owner) turned it out on his mill. It's a steel plate, 3/16" thick IIRC, cut on a rotary table. It would be real easy to do on a waterjet; hand the operator a .dwg file and a few bucks. Flywheel = gray, trigger wheel = white. A standard Ford pickup points forward (at the sides of the teeth), much like the mount you've seen for hall effect triggers.

BTW, a little design tweaking would save weight, but for those who have rear CG concerns, well....



Make the tooth width the same as the width of the tip of the pickup; that nets a clean sine wave signal for the EDIS module. See the blip on the right? That's the passage of the skipped tooth. This is the signal from a Ford pickup, and the large toothed wheel drawn above....



....and this is the signal from a Nippondenso pickup, with a 36mm diameter wheel made from a cut-down gear...the shop-made mag hole trigger on the previous page:


My original idea for timing pickup was using those 12 flywheel holes, mounting a magnet in a bolt in 11 of them. That would have given me an 12-1 wheel (12 teeth with one Missing tooth) which is fine for the Megasquirt (total teeth must be divisible by the number of cylinders). That is what I liked about the MS system, you have a lot more options in design, but the cost is learning it and the curve is kind of step, as the documentation is limited and support is tough to get. You need to figure it out on your own, so not for the feint of heart.

I ultimately discounted this alternative, as my pickup sensor would have been open to damage from a broken alternator belt.

Larry
 
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The Squirt boxes are certainly more capable, with many, many more options and choices...but the necessary complexity is also their downside. In contrast, the Autosport/EDIS approach is simple...just couple two boxes with a coil pack and a crank sensor. KIS is good in EAB.

Frankly, I like the OEM Ford module, as I figure it is far more hardened than any aftermarket control.

Dan, did you make those nice Pick-up units? Any interest in making me a set I don't have a lathe.

Speaking of reliability, the mag hole triggers do add some mechanical complexity to a reliability assessment. Bearing and shaft fits are examples; do them wrong and reliability suffers. I've also previously reported (in another thread) some possible resonant behavior at a mid teens RPM; the timing light goes a bit fuzzy there. Mags have the same problem, BTW, but we rarely observe it. I'm not worried, as the rotor is both robust and low mass, unlike a mag rotor and internal gearing.

The shaft is taken from a junk Bendix mag; the rotor leaves are removed and the shaft is re-machined. This approach makes it unnecessary to cut the taper, key slot, and threads for the drive gear.

The wheel is a re-cut stock gear. The body is cut from a chunk of 4" billet. Kirk did them while I was making the shaft assemblies, then I detailed them for bearing fit, o-ring groove, reluctor mounting, etc. The ND pickups came from an RX-7 distributor, which happens to have two of them. My favorite part? The pretty aluminum dust covers. They're cut-down cup holders intended for DIY poker tables.

No, I won't make more. As stated, I'm not going into the ignition business. You're welcome to drawings, in the spirit of open source.

Parts%20800w.jpg


Shaft%20Components.JPG


Re-machined%2036T%20Gear%20800w.jpg


Shaft%20Assembly.jpg
 
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The black bar "in front" of the gear is a bearing retainer. Correct?

Correct.

Is the electrical connector from the Mazda distributor also?

No, it's an Amphenol AT series connector, interchangeable with Deutsch DT series. I really like 'em. High overall quality, and the terminals crimp to the wires just like an oversize D-sub pin. Even the tool is the same, but in a larger size.

http://www.waytekwire.com/products/13/Deutsch-DT-Compatible-AT-Connectors/

http://www.deutschconnector.com/products/deutsch_connectors/deutsch_dt_series_connectors/

As an old car guy, I know that most electrical problems are really connector problems.
 
Deutsch----------havent heard of them in a long time.

I was a machinist for Deutsch back in the late 60s.

Yep, connector or ground issue were 90% of the problems for sure.
 
Frankly, I like the OEM Ford module, as I figure it is far more hardened than any aftermarket control.

Are you sure about that? Some aftermarket stuff is certified, others have been third party tested for vibration, EMI/RFI tolerance for use in military UAV applications where expensive sensor payloads are at risk.
 
Are you sure about that? Some aftermarket stuff is certified, others have been third party tested for vibration, EMI/RFI tolerance for use in military UAV applications where expensive sensor payloads are at risk.

You're right of course. I should have said "far more hardened than any certified, military grade aftermarket control available for about $100 brand new".
 
You're right of course. I should have said "far more hardened than any certified, military grade aftermarket control available for about $100 brand new".

Can't beat used OTS automotive hardware for the price point for sure.
With used, you could be fortunate that if it has lasted 10 years, it's going to last another 10 or 20 or unfortunate where a good portion of its life is already behind it...

Not all Ford electronics in the last decade have been great. The EDIS DOES have a good record in my experience and I especially approve of the ND pickups which are bulletproof in a fixed configuration- much more so than some other brands of OEM magnetic pickups which I consider unfit for aviation use unless you have two.

Some military applications are using COTS hardware/ software these days, well below the price range of Mil Spec electronics.
 
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Keep in mind that I'm not calling this a big success just yet. Let's fly it awhile.

BTW, not my first dance with OEM ignition parts. These are GM modules (actually NAPA TP45's), part of a dual ignition on a biplane in the 90's. Used ND reluctors for that one too. Fired two coils through an MSD coil joiner to single plugs. An earlier version was independent coil-per-plug. The really early version used Briggs and Stratton magnetos ;)

GM%20Modules.JPG
 
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Keep in mind that I'm not calling this a big success just yet. Let's fly it awhile.

BTW, not my first dance with OEM ignition parts. These are GM modules (actually NAPA TP45's), part of a dual ignition on a biplane in the 90's. Used ND reluctors for that one too. Fired two coils through an MSD coil joiner to single plugs. An earlier version was independent coil-per-plug. The really early version used Briggs and Stratton magnetos ;)


Yeah we built stuff like this for race cars using HEI modules eons ago and it worked just fine with the junkyard parts which was all we could afford back then. Brought back some good memories here. BTW, like your machine work and the creative cover design.
 
crank gear

Dan the crank gear looks like a simple way to go will the pickup work also with 3/16 aluminum or does the pickup need steel.
Thanks Bob
 
Working on a parts list to try this

Can I get one of you guru's to confirm a question on the spark plug conversion? I have not figured out what engines are using short vs long plugs.

With an IO-360-B1B using REM40E plugs, would be the short 18mm-14mm adapters (EFII) along with Denso IWM24 plugs and associated wires be a good starting point?
 
Can I get one of you guru's to confirm a question on the spark plug conversion? I have not figured out what engines are using short vs long plugs.

With an IO-360-B1B using REM40E plugs, would be the short 18mm-14mm adapters (EFII) along with Denso IWM24 plugs and associated wires be a good starting point?

Yes those would be the correct plugs and adapters to use.
 
As noted, I mostly consider this to be an experiment done for recreation and education. It is cheap, practical, and technically interesting, which are good reasons to do it. However, all choices are a matter of considered compromise. Before too many folks jump into the pool, let's review a few drawbacks.

(1) Francois (Frank from Quebec, our OP) has been running a complete dual system on his lathe, which has allowed him to document spark delivery in the cranking RPM range. Short version; from roughly 18 to 75 RPM, it is 9 BTDC, then retards to roughly 5 BTDC by 200 RPM. Between 200 and 500 it fires at whatever cranking advance has been selected in the Megajolt software, then transitions to the primary timing map.

This apparently works fine with cars, but could be a problem with airplanes, in particular airplanes with low inertia propellers. Typical impulse coupler lag angles for Lycomings result in cranking spark at either TDC or 5 BTDC, with most being TDC. A wood prop, a weak starter, and/or a weak battery may result in kickback when the system fires at 9 BTDC while cranking very slowly.

I've been cranking the 390 without a problem. However, I have a PC980, an inline Skytec NL, and metal Hartzell, so it cranks fast with lots of inertia. Based on Frank's excellent data, I'll experiment with a work-around for wood prop users, which is to set the base timing 10 degrees retarded, then set 10 degrees cranking advance in the Megajolt software, and add 10 degrees to all the advance map bin values. It will fire at 1 to 5 ATDC below 200 RPM, fire at TDC from 200 to 500, and fire at the desired advance when running on the main map.

(2) Confirmation of timing requires the use of a timing light, which means leaning over the running engine, in a very powerful breeze, with the prop spinning in near proximity. Many folks are not comfortable in this situation; there is definitely a risk.

Neither issue is unknown with other EI's. For example, P-mags users with wood props are advised to set timing a bit retarded to avoid kickback, and Lightspeed users have always been advised to confirm timing with a timing light.

There may be more to report as users build hours.
 
It's a cool project, nice to see people like Dan actually experimenting with low cost OTS stuff on an Experimental. Home brewed and off the beaten path is always interesting to me as is the design/ machining of the parts.
 
Starting advance is a concern

Based on Frank's excellent data, I'll experiment with a work-around for wood prop users, which is to set the base timing 10 degrees retarded, then set 10 degrees cranking advance in the Megajolt software, and add 10 degrees to all the advance map bin values. It will fire at 1 to 5 ATDC below 200 RPM, fire at TDC from 200 to 500, and fire at the desired advance when running on the main map.

Yes, with my composite prop this is a concern. Once I get an EDIS and a timing source this is one of the first things to look at. Same process, start with the lathe and work up.
 
An accessory case trigger with an ND reluctor has an interesting property; the toothed wheel naturally positions itself with a tooth centered on the reluctor tip. After all, it a magnet.

In the photo you can see I've marked the 9th tooth after the skip with yellow paint. To install the unit into the accessory case, place the crank at TDC, align the painted tooth with the reluctor, and slip it into the accessory case while meshing the drive gear. When in and clamped, the painted tooth is inspected to see if it is still aligned with the reluctor tip. The process is much like installing a mag using a stop pin. If fact, I could drill this assembly for a Slick stop pin, and may yet do so. For now, allowing the magnet to hold shaft position works fine.

Install%20800w.jpg
 
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Very Nice Work

I don't think you can use a mag hole drive on any 540 unless you built a gear reduction. On a 540 only a flywheel /crank nose will work. The Mags on a 540 are spun at an over speed RPM vs the 4 cylinder Lycs. This is why electroair never had a 540 Mag hole timing trigger solution and the same reason the PMAG/ EMAG is not yet available- very simply it is a beast of an engineering project. ( Perhaps I need to do some math here, as the 10 degree pitch spacing might be able to work in a 540 Mag hole reluctor set up)( I know that the 60-2 = 6 deg pitch spacing electro air could not be used in a 540 Mag drive)

That appears to be very nice install on your 390 and I especially admire the flywheel reluctor and pickup mount on Kirk Harrel's engine.

IIRC the mags on a 540 are driven 2x the RPM compared to the 4 cylinder in order to generate higher voltage /hotter spark. Perhaps is is only 1.5X but I am quite certain it is different than the 4 cylinder drive. I don't have an accessory case available at the moment but some AME or A&P on line will know for certain in a few minutes.
 
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I don't think you can use a mag hole drive on any 540 unless you built a gear reduction. On a 540 only a flywheel /crank nose will work. The Mags on a 540 are spun at an over speed RPM vs the 4 cylinder Lycs. This is why electroair never had a 540 Mag hole timing trigger solution and the same reason the PMAG/ EMAG is not yet available- very simply it is a beast of an engineering project. ( Perhaps I need to do some math here, as the 10 degree pitch spacing might be able to work in a 540 Mag hole reluctor set up)( I know that the 60-2 = 6 deg pitch spacing electro air could not be used in a 540 Mag drive)

That appears to be very nice install on your 390 and I especially admire the flywheel reluctor and pickup mount on Kirk Harrel's engine.

IIRC the mags on a 540 are driven 2x the RPM compared to the 4 cylinder in order to generate higher voltage /hotter spark. Perhaps is is only 1.5X but I am quite certain it is different than the 4 cylinder drive. I don't have an accessory case available at the moment but some AME or A&P on line will know for certain in a few minutes.


Elctroaire at one time did have a mag hole reluctor set up for the 540...a buddy mine used to have them installed on his Glassair III. He switched to Lightspeed after experiencing multiple reluctor unit failures.

Skylor
RV-8
 
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This is incorrect. The mag drive ratio of a 540 is 1:2, same as the 320/360. Also, Elctroaire at one time did have a mag hole reluctor set up for the 540...a buddy mine used to have them installed on his Glassair III. He switched to Lightspeed after experiencing multiple reluctor unit failures.

Skylor
RV-8

I suffered multiple pick up failures with an Electroair reluctor on the crank nose. The pickup mount on the nose was nothing worthy of an aircraft application. So I looked at making my own mag hole mount setup using a Slick mag for a bearing and shaft housing. Perhaps wrongly I concluded that it could not be done but Electroair told me the same thing. Now I will need to do some detailed study. Humble pie again.
 
This is incorrect. The mag drive ratio of a 540 is 1:2, same as the 320/360. Also, Elctroaire at one time did have a mag hole reluctor set up for the 540...a buddy mine used to have them installed on his Glassair III. He switched to Lightspeed after experiencing multiple reluctor unit failures.

Skylor
RV-8

Reference #1: PDF Page 2-5 of the 1970 Lycoming Overhaul Manual shows a typical 6 cyl. gear train diagram. The Mags spin at 1.5 X the crankshaft RPM.

A couple of diagrams above shows the typical 4 cyl. gear train with the mags at 1:1 with the crank shaft RPM
Link is Here: http://www.expaircraft.com/PDF/Lycoming-OH-Manual.pdf

Ref #2 as below :

An RV-10 Builder's Log: RV-10 IO-540 Ignition System Decision
buildingrv10.blogspot.com/.../rv-10-io-540-ignition-system-decision.html‎
27 Mar 2013 ... The IO-540-D4A5 260hp engines are shipped with: .... Most of the time, mag timing (fixed) will fire before or after an .... The 540 has a 1.5:1 drive ratio on the mags, which is different than the 1:1 ratio of the 4-cyl engines.”

It would look like a normal IO 540 can not use a Mag Hole Electroair 60-2 reluctor / pickup assembly because the mag drives are spinning 1.5 X faster than the crankshaft. That agrees with what I was told about 6 years ago.

Thankfully Dan Horton, Kirk Harrel and Frank from Quebec have put the E back into Experimental using the Ford 10 degree pitch spacing / 36-1 tooth reluctor wheel.
Thanks to Megajolt and Ford for making home brew ignitions much more within grasp for the average guy. I have an old 8N Ford tractor used for a tug that is soon going to have a modern ignition thanks to this thread!
 
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This is the other approach to a timing signal, a large tab wheel and stock Ford pickups, as installed on Kirk Harrel's Mustang. In this photo the second pickup is not plugged in, as he is using one Bendix mag while building hours with the EDIS installation.


Just moving the artwork back on display where it belongs :D
 
This is incorrect. The mag drive ratio of a 540 is 1:2, same as the 320/360. Also, Elctroaire at one time did have a mag hole reluctor set up for the 540...a buddy mine used to have them installed on his Glassair III. He switched to Lightspeed after experiencing multiple reluctor unit failures.

Skylor
RV-8

Don't know anything about the 540, but the 320/360 Mags spin at crankshaft speed, not 1:2. The mag produce 2 spark events per rotation (at 1:2 it would require 4 spark events). The rotor shaft has separate internal 2:1 gearing that spins the rotor at half the speed of the mag. Simply looking at the gearing show the crank and mag gears are the same size, which creates a 1:1, regardless of the idler gear size.
 
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The sixes magneto are overdriven 1 to 1.5 from the crank and then underdriven 3 to 1 for the rotor.
This way the magnets north-south poles are inverted and therefore producing electricity every 120 degress of crank rotation wich is what's needed for a 6 cylinder and the rotor is turning at the required half crank speed.
 
Mag Speed

Don't know anything about the 540, but the 320/360 Mags spin at crankshaft speed, not 1:2. The mag produce 2 spark events per rotation (at 1:2 it would require 4 spark events). The rotor shaft has separate internal 2:1 gearing that spins the rotor at half the speed of the mag. Simply looking at the gearing show the crank and mag gears are the same size, which creates a 1:1, regardless of the idler gear size.

Bonehead reply on my part. You're right, I completely forgot about the internal gear reduction for the rotor on the mags.

Skylor
 
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Electroair has a new mag timing housing for the pickup. I have it installed in the IO-540 in the RV10.

Vic
 
A dual crank-triggered EDIS system, like another other, require two pickups. With small Hall effect sensors and flywheel-mounted magnets, they are usually stacked along a radial, one outboard of the other. That approach is tricky with reluctors. One, the reluctors themselves are generally larger, so it is easy to run out of space. Two, the tooth width should match the width of the magnetic tip of the reluctor. That makes for interesting machining.

Look closely below. The second reluctor (currently not plugged in) is offset 1-1/2 teeth from the first reluctor, or 15 degrees.

The Ford EDIS module is hard-coded to provide fixed 10 BTDC timing above 400~500 RPM.

Kirk was very clever here. Combine the 15 degree offset and the 10 degree built in EDIS module advance, and he has a 25 degree advance. The result is a fixed timing electronic ignition without using a Megajolt controller...just a pickup, EDIS module, and coil pack.

Note that he can still incorporate a Megajolt and have variable timing on that second ignition if desired. All he needs to do is enter timing map values 15 degrees less than the desired values. For example, if 32 BTDC is desired at cruise MP and RPM, he would enter 17.

And yes, my friend Kirk is an experimenter.

http://www.experimentalairplane.com/kirk.html

Kirks%20Wheel.jpg
 
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Dan;
I like that idea.
I had considered a 2 mag pickup arrangement with a manual switch for TDC when starting, and 25 BTDC when running with a 10 degree retard for idle. No MegaJolt.
With Kirk's idea,you get both the start 'retard' and MegaJolt control, with a 25 BTDC fixed option if the MegJolt fails.
If this was powered by a Permanent Magnet alternator driven off the vacuum pad you would have total redundancy and modern control, finally exceeding the classic magneto in all regards? (except dead battery hand prop starting)
 
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