Electronic Ignition System's (EIS) IO 540 W1A5

[Hale-Yes]

Greetings, I would like to get the Maule communities input on the pros, cons, and colorful opinions, of the current batch of certified STC'ed EIS magneto replacements now available. There are three companies selling certified EIS units that I am aware of. These companies have STC'ed systems for the 4 cylinders engines as well, but I am limiting this post's information to the IO 540 W1A5 because that is what I have. The newest of the certified and STC'ed Magneto to EIS kits is (1) the Lycoming EIS, for the IO 540 W1A5 # 66K6D3SN-03 $1,650. This system is a fixed timing (23 degree) Magneto replacement. It use's the standard Slick spark plug harness. One unit can be installed with just a logbook entry. It is also legal to replace both Magneto's with 2 of these units, but this requires the addition of a back up battery ( there is one available as a kit from a third party vender listed in the Lycoming installation manual). A 337 field approval is required for the air frame modification, (additional wiring and back up battery). I like that this EIS is OEM Lycoming and the price is reasonable. The problem that I have with this setup is the fixed timing, the same setup is sold as experimental with variable timing. Come on Lycoming, WTF? After installing one of these units, I could add another unit later. If this unit had variable timing, it would be my pick.
Kit (2,a) is the ElectroAir EIS, for the IO 540 W1A5 using a crank angle sensor # 61000-T5C $3,940. or Magneto style (2,b) # 61000-T5M $4,440. Both kits come with spark plug wires. This system does have variable timing, but the STC is limited to replacing only one Magneto. The problem that I have with this system is the high cost and one unit limitation. Kit (3) is the SureFly EIS, for the IO 540 W1A5 # SIML6 $1,695. The STC is limited to the replacement of one Magneto. This unit has variable timing. The price is reasonable, it offers variable timing. Downside, the STC does not allow for both mags to be replaced.
I have zero actual experience with any of these systems, the information provided here is pilfered from the manufacture's website's, so please take with a grain of salt. I can't understand why Lycoming did not certify there system as a variable advance timing, when the others were able to do so. Hopefully they can in the future. It would also be great if Surefly could get a modification of there STC allowing two EIS units (with a back up battery and wiring). I am leaning towards the SureFly. What are your thoughts?

[drak130]

Hale,

I have the same motor. I looked into the surefly last year when the prepurchase inspection revealed that the mags were over due the recommended 500 hour inspection. At first the seller balked at having it done so I looked at the surefly. In the end the owner paid for the inspection so I have kicked the electronic ignition down the road.

It was my understanding that regardless of the company that the install in a certified aircraft required fixed timing. This was via a phone call with the surefly rep. Things may have changed or I am just wrong. My plan was to go with a single surefly mag, fixed 23 degree timing and then when the FAA pulled there heads out, plumb the mag for variable timing and the later when the FAA came to, install the second electronic mag.

Good luck

Tim

[Curtis]

A few years ago I installed a Lightspeed electronic ignition on a 220 Franklin. It was a big improvement over the mag. Easier starting, automatic variable timing, better fuel consumption and smoother power.
While flying, you could cut the mag off and there was absolutely no difference in the performance...no RPM loss, no power loss, nothing. However, turn the Lightspeed off and instantly a drop in RPM resulting in power loss. And you needed to start adjusting the mixture immediately.

Also, the Lightspeed works off of a crank trigger like modern day automobiles. Therefore, unlike gear driven ignition systems, you don’t have “gear lag”. It is much more accurate.

The experimental world is way further advanced in technology. Looks like one day the FAA would wake up and allow us to start using modern “up to date” technology instead of technology that is over a hundred years old.

[andy]

Apparently, the Lycoming EIS was developed by Surefly according to this web page https://www.lycoming.com/eis.

I would go for the SureFly one-mag system with my MX-7-180 since it doesn't involve a field approval. Quicker starting would be the biggest benefit. SureFly will probably come out with their own STC'd dual-mag replacement system at some point since they built the Lycoming system. Hopefully, their STC will include the replacement of the second mag and backup battery without having to buy two new SureFly mags or use a third-party backup battery.

[Hale-Yes]

Tim, I have done some further reading and your right, The first certified systems that Sure Fly offered were limited to fixed timing, but they now have modified there STC, and variable timing is allowed on most certified airframes including Maule's. Andy, It appears that not only did Sure Fly develop the EIS for lycoming, as you said, but they are building it as well. I did read on Sure Fly's FB page that they are developing systems for duel mag Lycoming's and working on getting FAA clearance to replacing both mags with an EIS, but it is very likely that the requirement for a dedicated back up battery connected to at least on one unit will remain. The other item that now seems to be sorted, is one where some Sure Fly owners with 24V systems were reporting rough running and engine stumbling. This was traced to dirty line power with high voltage spikes coming from some 24v alternators. The Sure fly system was shutting down and resetting momentarily to protect it self from the high voltage spikes, as it was designed to do. Sure fly now has a small FAA approved box that uses capacitors and other electrical black arts to smooth out the line power. To my way of thinking, finely getting FAA approval to allow EIS on certified aircraft is a big deal that is decades to long in coming. I remember when I was a kid (a long time ago) that some of my Fathers oldest tractors had Mag's on them. Now the only implement with a Mag on it, is a small Oliver track layer that bought from a neighbor years ago for my kids to play with (it still runs). I keep it for yard art.

If we can just get the FAA to allow real fuel injection, we could drag single engine piston aviation into the 1980ies! Happy New Year to you all ! (and good riddance to 2020)

[andy]

Everything electronic these days has an integrated computer chip that boots up when power is applied. The power coming out of the alternator is full of high and low frequency noise and voltage transients. When alternator brushes get old and worn there is less force from the springs pushing the brushes against the slip rings, which can cause them to "chatter". At that point turbulence can create enough vibration to create a voltage transient that will make the avionics think that power has been removed and re-applied, which will cause them to reboot. That happened to me on my Apollo GX 60 GPS/COM and my JPI EDM 800 engine analyzer in flight several times about 5 years ago. Before I or my A&P realized what was really happening, I ended up sending both units out for repair. Inspecting and replacing alternator brushes isn't something that is a normal part of an annual, but I think it should be.

Maule has an optional noise filter that can be installed per one of the drawings on my parts DVD. I've been thinking about installing it on my Maule. Does anyone have one? What do you think of its effectiveness?

[Andy Young]

I have a noise suppressor on mine. Can’t honestly say what it is or isn’t doing, but I haven’t had any of the problems you describe.

For what it’s worth, removing and measuring alternator brushes is on the Annual/100 hour checklist I built, and have shared with some on here. Even aside from the problem you describe, better to catch worn brushes at inspection time instead of having the alternator stop charging far from home, or in IMC. That’s my long way of say that I agree with you.

[norcal64d]

I am using a Surefly on my O-360-C1F. Its a long story but I did the STC and install to allow it to use variable timing and ended up changing it back to fixed timing. I was flying at high DA in Colorado and the Surefly advance scheme basically lets the system go to full advance of 37 degrees at 21" of MP and below regardless of engine RPM. In the late spring and summer time with a field elevation of 6800ft, I was only getting around 21" of MP at takeoff with full throttle which mean the mag was fully advanced while I was trying to takeoff and climb. I lost about half my climb rate and had several hundred feet extra added to my takeoff roll and being at 9500-9800ft DA, its not like I had much extra performance! After talking to Surefly and reading lots of user data on the relationship between ignition timing and max power, I switched back to fixed timing and have used it like that ever since. I think the system would be ideal for aircraft based at low elevations that want to climb up and cruise LOP which is how they tested the system. For my case though, it turned out to not be ideal for my conditions.

I think it is a good system for lower elevation planes but I would not use the variable timing for high DA takeoffs. I know this is a different engine than yours but hopefully you might get some useful info for your decision. In fixed timing mode I have been very happy with the Surefly, the plane starts better at 0F on the first start of the day than it did with Slicks on a nice pleasant day. I kept on impulse coupled Slick and took the jumper off the ignition switch so I have both firing when I crank.

[Hale-Yes]

Tim that is great information and it may be the answer to my question as to why the certified Lycoming's EIS (built by Sure Fly) is a fixed timing system (in my case IO540 W1A5 is fixed at 23 degrees of advance just like the mags). Perhaps they are working on this problem (caution, complete speculation on my part). The Lycoming rep who wrote me back said that they had some bugs to work out before selling a variable timing system. Another interesting thing I read was that Sure Fly's experimental system has a small alternator built into each of the units to provide power in case of a general electrical system failure, with absolutely no knowledge of the inner workings of the experimental Sure Fly system, I like the sound of that much better than relying on a back up battery and more wiring.

[andy]

I like the idea of electronic ignition for quicker starts, better fuel economy, a little more power and avoidance of the 500 hr mag inspection. But I don't like the idea that a general electrical system failure would stop the engine without a backup battery system. I also don't like the idea of having to install a 3rd party backup battery and wiring, including the additional cost and weight. I'll wait to buy until SureFly includes the backup battery in each of their mag replacement units like Garmin did with the G5. That will be challenging since the power required to drive the spark plugs is a lot more than what is required to drive the G5. Also, there's not much space where the magnetos are mounted on my MX-7-180, so including a backup battery in the housing would be tricky but not impossible. I think an hour of backup battery capacity would be enough to get you on the ground safely.

[norcal64d]

I am curious to see if Lycoming uses a similar map for their advance as Surefly, or if it will be something else entirely. My conclusion is that if the Surefly continues to give me excellent starting, doesn't require any maintenance, and continues to not have any change to its timing over time, I will be very happy with it. My installation is wired directly to the battery so in the event of an electrical fire or alternator failure, I can quickly just turn the battery off and not lose a mag. I will run out of gas long before the battery goes dead from just the Surefly current draw.

[VA Maule]

Just a real shame that we can't utilize the E-mag . They have an internal alternater that provides it's own self contained power supply, so no back up battery foolishness to put up with. Sadly though their still EXPERIMENTAL only. I've spoken the FSDO in Richmond ( Socialist republic of) Virginia and been told " We don't do field approvals any more ". So true to form with their motto " We're not happy until your not happy "

[andy]

Yes, E-MAG is definitely the way to go if you're experimental. No external battery or wiring to worry about. Power generated by internal engine-driven alternator. Variable timing. I see that Lycoming is one of the OEM partners. Maybe they will see a market for certified aircraft. I would buy two of them if they were certified.

[Desert Fox]

The power draw from some of these electronic ignition systems is quite minimal. I converted the GSO-480 in my non-Maule bush plane (UTVA-66) to dual PMAGs. It starts immediately, runs much smoother and is more efficient. It uses minimal power from the electrical bus. The install manual claims less than 0.5A in normal conditions and less than 1.0A with the internal alternator inoperative. I assume that is at 12V but the PMAG will accept up to 48V. The Lightspeed in my Pitts is more accurate due to the crankshaft sensor but still is not a major power drain. The plane has a little B&C alternator (8A, if I recall). Unfortunately the above are all experimental still. Possibly the PMAG will get certified soon.

In the meantime, the Surefly system is a nice single magneto replacement. I am putting a Surefly Sim in an M7 as a Slick replacement. Has anyone removed the remaining Slick 6300 series and replaced it with a Bendix? The IO-540-W series parts catalog shows a Slick 6300 or Bendix 1200 but does not give a corresponding ignition harness part number for the Bendix 1200 option.