Leburg ignition replacement

[Pietflyr2]

Thanks guys, your posts cleared things up for me. I read Norms post on HBA as well.

[karmarepair]

Skycraft in the UK is carrying on the Leburg ignition, but it's a bit spendy. http://skycraft.ltd/acatalog/Leburg-Dual-Ignition-Kit-for-VW-Aero-LEBURGDKIT.html

[Pietflyr2]

I did see that site. They also have a single ignition. Just for grins I did the pound to dollar conversion on the dual ignition, $1043, plus shipping!

[Mark Kramer]

Hi Kamcoman
I am also very interested in the gm parts ignition system using the hand drawings that Dan posted. When looking on eBay the part numbers listed on the drawing don’t exactly match numbers of parts on eBay. Was wondering if you would post the numbers of all the parts you used? Also why did you use two different sensor units for start and run. Another issue for me is my Mosler case is different in the front than a v-dub, and I’m not sure if I would have the room to mount the sensors. I think a better way in my case might be to remove the Fairbanks/Morse mag and go off the crank. The problem there is that there are no threaded holes in the crank end to bolt on a disc for sensor bolts or magnets. Any ideas?
Thanks Mark

[Kamcoman77]

The reason I used different sensors for the Run & Start was simply because I had one of each lying around. The GM sensor (AC Delco #24203876) sensor puts out more voltage (7.5v - 9.5v) than the Ford ABS, so using two of the GM is probably the best way to go. I used a generic 4-pin GM module and also tried a Proform 66944c high output module. Couldn't see any difference in the spark. To trigger the sensor, you use a bolt, or other piece of steel/iron, don't need a magnet. The sensor has a magnet in it and generates a voltage as a metallic object passes it. Gap of about 0.030" between sensor and trigger bolt seems to work best on my test setup.

[Kamcoman77]

Here is a screenshot from a short video of my GM module, 4L80E pickup sensor, Buick V6 coil, and NGK BR8HS plugs (gapped 0.035") test bench setup. The disc that triggers the pickup is just a bolt in cardboard. The disc speed was about 3,000 rpm. I was using 12-volts from a 6-cell 18650 li-ion battery pack. Sorry I could not load the video but it is in MP4 format and I think it has to be in MOV format to post here. The spark was quite intense.

[Mark Kramer]

Thanks so much! I’ve had my mag off several times, but never really looked at the crank end. It has a notch across the end, but no bolt holes I don’t think. Would love to just bolt on a disc and go from there. Think I will see if I can find these parts and go from there. I really want to replace my mag with electronic ignition. I would fly it with the mag, but cannot find a runway with an available hanger! Checked everything for 50 mile radius. All dressed up and no place to go. Joining the closet EAA chapter, maybe they will know a place.
Thanks again

[Mark Kramer]

Hey Kamcoman

I have a couple more questions maybe you could help me with. Electrical stuff is not my thing. Plug wires, in my mind should be the solid copper wire type, not the carbon suppression type. What did you use? On my eBay list they wanted 30 bucks for two wires, and they were the only item that wasn’t free shipping, 35 bucks for that. Gonna source them elsewhere. Want them to plug right onto that Buick coil. Also what awg size wiring should I use to connect all this stuff and the switch? Wonder if the switch should be an aircraft grade switch? Again electrical is not my forte,and would appreciate any help I can get.
Thanks again

[Mark Kramer]

Also, after my last post I was looking on line about the DM1906 hei 4 pin unit and it said that it needs 7 volts min and would function best with 12-14.5 volts. I wonder if there is a sensor that would output 12 volts?

[Wayne Munich]

I am using a flying magnet. Bosch TK139 ignition module with two ZF MP 100701 Hall sensors. The magnet is 3/16 dia. mounted in a aluminum holder screwed on the end of a prop bolt. The sensors are only an inch long which helps with clearance issues. They also  switch at zero speed, unlike magnetic sensors which do not, their output is proportional to speed,  Easier starting with a hall sensor and less susceptible to noise.

[Kamcoman77]

Mark,
The 12+ volts for the GM module probably refers to the working voltage of the power supply, not the pickup. My Ford ABS sensor only put out 4.5v to 6v and the spark I got looked just like the higher output 4L80E sensor. I used MSD racing wires on my test setup. They are solid wires wrapped in a very tight spiral configuration for noise suppression. Summit Racing may sell this wire by the foot and a pack of ends; you might want to check their website. Wayne Munich's setup may be the way to go for you, since some hall sensors can be very small and use a small magnet to trigger. I can't remember if I tried the hall sensor pickup with my GM 4-pin module, but it should work (see diagram). Aircraft switches will probably be safest and aircraft wire. I'm using 16ga wire for my switch to sensor, sensor to module, module to coil, and battery to system.

[Mark Kramer]

Ok, a lot to digest. Firstly my engine is a Mosler, so there is no distributor hole. Mag attach on the back only. My brain says electronic ignition with no moving parts over a 30 something year old magneto. Hence me picking you guys brains. Now I talked to Scott C. Today and comparing the two systems all he would say was that a magneto almost always will give you a warning before complete failure. Electronic ignition most likely will give no warning. If I had access to a runway and a hanger, it’s a no brainer, I’d fly the mag and design a electronic system later. Unfortunately all I have is time, and I think too much.
Back to the electronic systems at hand, and remember I’m not too bright in this arena. As far as Wayne’s system, I could not find a Bosch tk139 on line. Kamcoman, on your schematic are you showing only one hall sensor? And is that a resistor or some kind of electrical check valve in the middle of the drawing? I’m assuming there would be two hall sensors and a switch to select start or run. I also like Wayne’s set up, but I think there is more there that I don’t understand. No selector switch there? Is there programming involved?

[Kamcoman77]

The schematic is one I copied from the internet just to show a 4-pin module can be triggered by a hall sensor. The 1 K ohm block is a 1 kilo-ohm (1000 ohm) resistor. Since hall sensors have the three wires, ground, signal, and power, to hook up two sensors you would probably hook the ground from both sensors together at the module, the two signal wires together at the module (with a diode in each wire to prevent signal backflow), and run the power wires to the Run/Start switches. Probably should show both circuit drawings to an electronics knowledgeable buddy to get the wire routing and resistor wattage correct. Don't know what you mean about programming; there is none on the circuits I posted. Perhaps Wayne's? If you are interested in a programmable, computer controlled ignition that only needs one pickup sensor, there is a system you can purchase from Transmic.net (https://transmic.net/2019/08/21/dc-cdi-v7/) that allows you to program a spark advance curve to suit your desire. Does not come programmed with a spark advance curve that will work for us (hand propping). I have one that I will use on my engine test stand during break-in to see how it works. It puts out a nice, hot spark on my workbench. I had to buy a Pickit programmer to program a spark curve in the computer chip (lots of new learning for me).

[Wayne Munich]

Yes I am using a selector switch for start and run. The sensors are fixed at 28 degrees apart on the four inch arc. The Bosch module can handle 6 amps so a 5 ohm coil is used to preclude the need of a ballast resister. Like all the modules, a heat sink is required.

[Mark Kramer]

As far as the programmable, yes I was referring to Wayne’s set up. Told you I am dumb about this stuff. I would prefer the simplicity of a two switch system, and nothing that needs programming or diodes and resistors. So I’m back to the simple gm set up. Scott assured me that there is a bolt on adapter in between the crank end and the mag. Should be able to bolt on a disc right to the crank, maybe some more spacing behind it to clear the crank case. Go from there with some sensors.