Primarily for general aviation discussion, but other aviation topics are also welcome.
By Silvaire
Delta Juliet wrote:Starting is much improved as the electronic ignition gives a 1/2" spark which is independent of engine speed. At low speed the system changes the ignition to about 0 degrees advanced (compared to the fixed 20-25 degrees of a magneto). This prevents kickback.

Impulse couplings do the same thing. Electronic spark is typically strong (as noted) and that would the (only) difference for starting if the engine type otherwise has impulse couplings.

Delta Juliet wrote:At speed, the ignition is advanced depending on the rpm and manifold pressure. At full power I never noticed much difference, but when leaned and pulled back in the cruise 20"MP/2100rpm there was a big difference in airspeed compared to std ignition. The system advances the spark up to 40 degrees which makes the engine much more efficient. The advantages are better starting, 10-15 kts extra cruise (135 vs 120kts) and the ability to use Iridium car plugs at £36 a set of 4.

No mention of the altitude here, but given only 2100 rpm it might imply low altitude. In that situation, throttled way back to max range cruise (ie 20 inches MP) you'd see similar advantages to unavoidably running low MP at altitude. Works for a very high powered aircraft. However, if you don't run extremely low MP on a given aircraft the spark will not be advanced to the same degree, and so the advantage will not accrue to the same degree.

For example, if (like some people flying relatively low powered aircraft) you fly around with almost full throttle at low altitude, you'd probably see no benefit - because that's what standard mag timing is spec'd for.

135 kts versus 120 kts takes about 40% more power by rough calculation, so assuming the same fuel flow its equivalent to saying that advancing the spark for max range cruise provides 40% improvement in SFC.
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By hatzflyer
Bill McCarthy wrote:Has the LEBURG system been resurected for the good old VW hatz ?

It has been adopted by Dave Almy . I believe he is in the process of making some improvements as some of the component suppliers "dried up ".

It' s suitable for more than just the VW.
The LAA are following the lead of the EAA and far more automotive engines with electronic ignition are being tested including v6 and v8 types.

I think the writing is on the wall for mags. :D
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By Delta Juliet
Impulse couplings do the same thing. Electronic spark is typically strong (as noted) and that would the (only) difference for starting if the engine type otherwise has impulse couplings.

Sort of.

Normally only one magneto has the impulse so you start on a single magneto. With the lightspeed you can have both the electronic ignition and impulse mag operating during start which gives much better starting. I think the EI is actually firing the mixture as the spark is very strong.
By Silvaire
Piper Aircraft (the Crown Principality of Economical :lol: ) did certify a lot of planes with only one impulse coupling... but on other manufacturers aircraft it is typical to have impulse couplings on both mags. There are arguments for doing it both ways.

A self contained drop-in electronic "mag" is potentially a great thing if designed and built properly. I'd have no interest if it weren't independent of ship's power, but in recent years the developers have smartened up and realized that a lot of potential customers see it the same way.
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By 4535jacks
I am in the process of adding dual electronic ignition on my Potez. I am in the early stages and I have approached the LAA. They are not against it as I think they realise that electronic ignition is the future. I am interested the Leeburg system now manufactured by skycraft, it will cost around £1000 and is British. The other system I was looking at was the Lightspeed which will be £2000 and is American. The LAA said it would be very easy and quick to approve the Lightspeed system as it has been used on so many other engines that they hold a lot more data. The Leeburg will be slightly trickier as it now being manufactured by a new company and the old system did at one point suffer from a problem where transistor kept on breaking. Therefore in order to approve the use of dual Leeburg ignition on a Potez, the LAA would need to visit skycraft inspect the system and do more research.

The LAA also recommended looking at E-Mag and P-Mag but as my engine does not have mags, they would be very difficult to fit.

My aircraft has two batteries, 1 main battery and a secondary battery which is only connected to ignition and I have the option to flick between the two. The alternator charges the back up battery first and then the main. I think this system is well suited to Electronic Ignition because if I have an alternator failure then and my main battery goes flat, I will have enough left in the back up battery for at least 45 mins and probably more, plenty of time to get down. One feature I like about the Leeburg is the led that tells you that the unit is faulty.
Last edited by 4535jacks on Tue Feb 12, 2013 4:41 pm, edited 1 time in total.
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By Delta Juliet
As Silvaire has said, Lightspeed are in the US at Santo Paula airport in California.

Your price of £2000 seems high. The prices on their website are $1195 for the lightspeed II which I use. This about £800 plus VAT and shipping.

They are very helpful.

They have 3 different pickups for their electronic ignition. One is designed specifically for Lycomings, but the other two are mounted near the starter ring and involve drilling a small hole in the starter ring. Magnets are inserted in these holes and trigger ignition as they pass the pickup.

I would think that these could be adapted to other engines quite easily. All you need is a way to make the magnets rotate past the sensor.
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By 4535jacks
I think $1195 is for the single system whereas I intend to fit dual ignition which is $2395 + VAT and shipping and I don't think I would get much change out of £2k. But I would live to be proven wrong.

I would like like to see a system where the electronic ignition timing has two presets, power and economy which you could change between depending on what you are doing.

Would this be possible?
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By Delta Juliet
I would like like to see a system where the electronic ignition timing has two presets, power and economy which you could change between depending on what you are doing.

Would this be possible?

yes, they are called the throttle and prop control. The electronic ignition just sets up the optimum advance for whatever you set the rpm and MP to.

I don't think the LAA allow two electronic ignitions in the UK. They like one electronic and one magneto, just in case the battery fails.

In my experience you get 90% of the benefit from just one electronic ignition. It fires the cylinder way before the magneto, so the flame front in the cylinder has disappeared off before the magneto fires the other plug. That is why you get no mag drop when you turn the magneto off in the run up checks.

Of course, you can fit two electronic ignitions, but you'd then need two batteries and a way to charge and isolate them. I don't know why you'd bother if you have a magneto.
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By Rod1
“I don't think the LAA allow two electronic ignitions in the UK.”

The Rotax 91X engines all have two electronic ignitions.

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By Delta Juliet
Yes, you are correct. I was thinking Lycoming rather than the Rotax etc. Perhaps I should have said replacement of both magnetos with electronic ignition.

The situation may have changed now at the LAA, but as I said, you get 90% of the advantage with just one electronic ignition and don't need a second battery.
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By 4535jacks
I have spoken to the LAA and they are not against dual ignition but it will have to go trough the major mod process.

With respect for two batteries and an isolation system, my aircraft is already fitted with all that as it has dual coil ignition with a distributor and not mags.

I wish to go for dual ignition because they stopped making parts for the Potez distributor about 50 years ago and parts are as rare as hens teeth. So for me the jump to dual electronic ignition is an easy one that will make it easier to keep my aircraft flying.
Last edited by 4535jacks on Tue Feb 12, 2013 6:09 pm, edited 1 time in total.
By Barcli
If it is of any help - the guys that built an RV7 G-GERT a few years ago fitted a faded controlled I0-360 which If I remember correctly definately had two Lightspeed electronic " mags" - so the LAA have approved it before.... You could use G-INFO to contact the owner , whom I am sure would help......
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By Trent772
LAA do allow dual EI.

We have dual P-Mags on our RV7 G-IVII as does Steve Sampson on G-IKON.

Many advantages - semi mapped advance and retard using manifold pressure.

Also, if you are using a lightweight starter, the ignition is inhibited until after TDC to allow purging of the inlet, hence no backfires which can damage the starter casing.

Great starting hot or cold, runs NGK car plugs.

Brad is developing a certificated version

UK distributor is