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Lycoming New Electronic Mag Osh 2019

PilotjohnS

Well Known Member
At Oshkosh 2019, Lycoming announced their new electronic ignition system. It replaces the traditional magneto.
In the booth, I talked to the Subject Matter Expert about it.
I looks like a regular mag, uses a P lead and requires a redundant power source for certified aircraft.

The advantage I see is that it does not run software like a E Mag, but rather uses a Programable Logic Device that gets hard encoded during manufacturing. This means no software to update or get corrupted, but requires factory returns for firmware updates.

One disadvantage is that it doesn't self generate its own electricity, but the SME is working on that.
Another is the mechanical tach drive is tight. I talked to Garmin and the G3x can sense the RPM from the P lead if it works the same as the mechanical tachs.
 
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Yes, Surefly.

Lycoming's initial interest is the certified fleet operator who is currently spending a lot of money to overhaul Slicks at 500 hour intervals. The Surefly concept incorporates the Slick mag cap and harness, as well as the standard aircraft plugs, so the swap is painless. The installing mechanic adds only a power lead.

Their long term interest is the Type Certificate market...standard equipment EI on production aircraft.

My understanding is that Lycoming will specify a specific part number for each engine model. Initially all will be fixed timing, no advance schedule. They do plan to add an advance option, again tailored to specific engine model.

There were considerable revisions of the original Surefly to arrive at the current shared version. The Lycoming reps stated there will be no physical or mechanical difference between a standard Surefly purchased directly, and the certified Lycoming version. The only difference will be Lycoming's choice of advance schedule, which will vary by part number. At this time, Lycoming considers the advance schedules determined in the dyno rooms at Williamsport to be proprietary; they will not publish them.

The Surefly currently sold for EAB use offers a user-set choice of 18 through 30 degree fixed timing, as well as 18 to 30 base timing with an advance schedule. The current advance schedule is "one fits all", and as noted in previous discussion, appears to be fine for a parallel valve, while being too advanced for an angle valve. It will be interesting to see what becomes available after Lycoming settles on its own schedules.
 
Photos show a MAP connection point on the rear of the units which you'd have to connect to have MAP advance, which may be of more importance to Experimental users. As Dan points out, the Cert market is huge and probably what Surefly and Lycoming care about most. The Experimental market already has plenty of choices offering both more features and lower prices in some cases. Electroair also offers certified EIs but the Surefly price point will put a lot of hurt on their sales IMO.

If these are reliable, they should offer a fair cost savings to fleet operators jamming a lot of flight time per day on their engines. Good move on Lycoming's part, this should bring in a lot of revenue for them though it may hurt the mag overhaul shops.
 
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Not for the targeted retrofit market, which is fixed timing.

So, if I understand correctly, without the manifold pressure tie-in you wouldn't get the starting benefits with the Lycoming part, you would have to use the Surefly part.
 
So, if I understand correctly, without the manifold pressure tie-in you wouldn't get the starting benefits with the Lycoming part, you would have to use the Surefly part.

If by "starting", you mean engine start, the MP line has little to do with that. All ignitions need to have a "start retard" mode to prevent kickback. This typically is sensed by low RPM or a discrete signal from the starter circuit, not MP.

But it does bring up a point of Lycomings intent WRT starts... Does it have this retard circuit or is the EI dead when cranking?
 
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A MAP line has nothing to do with starting. Start retard is built in.

With a Surefly and one non-impulse mag, start using the Surefly, while the magneto P-lead is grounded.

With a Surefly and an impulse-coupled mag, start using both.

With two Surefly units, start using both.
 
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Photos show a MAP connection point on the rear of the units which you'd have to connect to have MAP advance, which may be of more importance to Experimental users. As Dan points out, the Cert market is huge and probably what Surefly and Lycoming care about most.

As noted previously, Lycoming intends to establish proprietary advance values for certified installations, at the Type Certificate level. In other words, they intend to deliver ignition advance on new engines and aircraft, as well as within the aftermarket

The Lycoming branded units are identical to the Surefly branded units. An EAB user may prefer the Lycoming vetted and certified advance values. The interesting thing to watch is what Surefly will do about their one-size-fits-all advance values when their partner is saying one size doesn't fit all.
 
Interesting development with Lyc tied to the hip via TCDS with unique advance schedules for each engine type. It won't be long before the "proprietary" advance map is common knowledge and we can see what they come up with. I'm guessing it will be conservative, but I also guess the difference between the AV and PV engines will be noteworthy. This is going to put a cramp in the "one size fits all" concept of the other EI products (as well as Surefly).

Good stuff here!
 
Good stuff here!

The much-overlooked backstory is the engineering review and development time Lycoming put into the Surefly. This has been an ongoing partner project for some time, with product changes to satisfy the FAA and Lycoming.

Tapping the resources of an OEM is a big deal.
 
Surefly

Well, I can attest to the SureFly mag as a game changer for my airplane. My hot starts are better and it runs so much better. I have had it well over a year and it has performed well over the last 170 hours. I will also say the customer service is outstanding. Highly recommend.
 
will Surefly recommend an advanced timing schedule for these for experimental? based on type of fuel, compression ratio, engine size, carb or FI, etc.
 
SureFly settings

Well for me when I called up to order mine we discussed my engine and they helped me figure out what I needed to do with mine. It sure would be worth a call. Like I said they are very helpful.
 
Well for me when I called up to order mine we discussed my engine and they helped me figure out what I needed to do with mine. It sure would be worth a call. Like I said they are very helpful.

I currently have an order with SureFly due to ship next week.
Are you running one side? Impulse or non-impulse?
Or both?
 
Very interested. If you install dual SureFlys, what size and type of battery would you need for an adequate back up system?
 
Very interested. If you install dual SureFlys, what size and type of battery would you need for an adequate back up system?

Jason, the SureFly GM, I believe he's been running 2 PC680s on a dual setup in his RV7 for the past year. He may be on this forum and make a comment.

If I decide to go duals, I'll be adding a 2nd PC680. I'm waiting to hear about the cost to rebuild my old Slicks to decide whether I go dual at this point. I should find out tomorrow.
 
At the show

Very interested. If you install dual SureFlys, what size and type of battery would you need for an adequate back up system?

So I talked to one of the mag engineers about the Lycoming version at the show and he mentioned a 3 ahr battery would be good for 45 minutes, if I remember right. He said a simple diode tap to the main bus to keep it charged is sufficient.

JMHO YMMV
 
Jason, the SureFly GM, I believe he's been running 2 PC680s on a dual setup in his RV7 for the past year. He may be on this forum and make a comment. SNIP

This is the right way - but do not overlook all the opportunity offered by a dual battery setup like this beyond just ignition power backup. In other words think “system” not just “component”.

I run dual PC-625s for this reason - even though I have dual pMags that require no power backup.

Carl
 
I just installed the Surefly on my Grumman Tiger (via STC) a few weeks ago. I tied the manifold pressure to a fitting I installed on a cylinder plug (located above the primer nozzle). The unit works well. I replaced the left mag so I could get rid of the impulse coupling. About the same weight as a slick magneto and probably won't have to retime or do any maintenance to it. While it doesn't have the internal power generation of a p-mag, I believe it is more simple and less prone to malfunction than the p-mag (however, it needs an external power source to operate properly).

Ellis.
A&P / IA
RV 7a bulder
 
Surefly

The real reason I would choose the Surefly over the PMag is that the Surefly doesn't run software. They use a PLD, or Programable Logic Device. This has the firmware burned in and is hardened against software glitches caused by muon particles and such. To me this is the minimum requirement. Being a software guy, I dont like software controlled critical systems. Ya I know, all EFIS’s are software driven, but those are redundant on many levels.
 
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Help me to decide, please -- Advanced or not

I have my Surefly on order to replace my Bendix impulse mag -- also have a "Slick-type) harness on order. I have run the power wire with the 10A fuse from the battery, and ready to go on the install ----

My choices are to hook it up as "fixed" timing (25*) or hook up the MAP for automatic timing advance. My engine is a Lyc O360A1A with added FI and Hartzell CS. My average flying is mostly hamburger runs, instrument currency, "play-time" and the occasional cross country -- most everything at less than 10K MSL. I average 50-60hrs /yr on this machine.

So, question for those with EIs with and without advance -- for my profile, any advantage/disadvantage to going with the timing advance hookup?

Thanks for the help,

Ron
 
Mag replacement

I second Ron?s question. We do a lot of cross country and some high altitude. I?m due a 500 hour AD now. This seems like a good option. Thanks
 
What is the SureFly advance curve (vs MAP) for the parallel valve? I looked at all the literature and can not find that.
 
OK, my dumb question..

Sorry if this is a dumb question, but how does it work when running a single electronic mag with variable advance timing? In this case you would have an electronic mag with variable advance timing next to a conventional mag with fixed timing. Obviously, this mismatch would not work.:confused:
 
Sorry if this is a dumb question, but how does it work when running a single electronic mag with variable advance timing? In this case you would have an electronic mag with variable advance timing next to a conventional mag with fixed timing. Obviously, this mismatch would not work.:confused:

It does work (rough, simplistic statement). The one that successfully lights the fire first wins.
 
It does work (rough, simplistic statement). The one that successfully lights the fire first wins.

Thanks for the clarification. So the e-mag does all the work and the mechanical mag is there firing away, but really only serves as a backup ignition source? Interesting - I never would have thought it would work like that.

And the e-mags single plug firing is still better than 2 conventional mags firing 2 plugs?

It's too bad they cost what they do. They would never pay for themselves verses conventional mags.
 
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I have my Surefly on order to replace my Bendix impulse mag -- also have a "Slick-type) harness on order. I have run the power wire with the 10A fuse from the battery, and ready to go on the install ----

My choices are to hook it up as "fixed" timing (25*) or hook up the MAP for automatic timing advance. My engine is a Lyc O360A1A with added FI and Hartzell CS. My average flying is mostly hamburger runs, instrument currency, "play-time" and the occasional cross country -- most everything at less than 10K MSL. I average 50-60hrs /yr on this machine.

So, question for those with EIs with and without advance -- for my profile, any advantage/disadvantage to going with the timing advance hookup?

Thanks for the help,

Ron

I would suggest you contact Surefly, and ask the questions. My understanding is that when you have the SIM set up for advanced timing, it will not advance until the engine is well within the safety margins for advance. Unlike an automobile, we do not have anti-knock (detonation) sensors to protect from over-advancing the ignition. So, until you get the engine below a certain power via reduced manifold pressure (because of throttle or altitude), the SIM stays in a fixed timing mode just like a MAG. The philosophy being that in cruise, the SIM will safely advance the timing and give you a more efficient burn in the cylinder.

This system is the most tested electronic ignition in the industry. I suspect the ignition curve is proprietary, and that the previously illustrated curve is out of date (it was published with the initial announcement, before development was complete). It will run for hours on just your battery, and a back up battery is being developed. I run dual SIM's on my RV6 with IO360, CS prop, and Gami's. Starts better, runs smoother, and LOP at cruise is as smooth as reducing the throttle.
 
So the e-mag does all the work and the mechanical mag is there firing away, but really only serves as a backup ignition source?

I would say no. The fixed timing magneto only becomes irrelevant if the opposing flame front has already passed when it sparks.

The initial inflammation and subsequent flame spread requires time. For illustration, let's ignore spark rise time and the relatively slow growth of the initial flame kernel, the zero to 10% mass fraction burned period in the textbooks. Start at the 10% burned point and consider only the travel speed of the subsequent flame front, somewhere around 25 m/sec (i.e. 985 inches per sec), for an engine like the parallel valve Lycoming. Bore is 5.25", with the plugs roughly 3.5", maybe 4" apart.

2700 RPM is 0.00006 seconds per degree of rotation, thus a 13 degree difference in timing (i.e 38 BTDC for the EI and 25 for the mag) means the mag would lag 0.00078 seconds behind the EI. 985" x 0.00078 seconds = 0.7683". The EI's 13 degree head start moved the flame front less than an inch across the chamber...not yet to the other plug.

So goes theory; an experiment is required to prove or disprove. Fly a fixed pitch RV with magneto and EI at some altitude which significantly advances the EI. Ground the magneto. Is there an RPM drop? If so, the magneto was contributing to the combustion process.

Reports welcome.
 
I would say no. The fixed timing magneto only becomes irrelevant if the opposing flame front has already passed when it sparks.

Hmmmmm this is getting messier. The next question then becomes why is it so important that we time our 2 conventional mags to fire simultaneously? Your post makes it sound as though that isn't particularly important.
 
Hmmmmm this is getting messier. The next question then becomes why is it so important that we time our 2 conventional mags to fire simultaneously? Your post makes it sound as though that isn't particularly important.

Not messy at all.

Mag/mag, mag/EI, and EI/EI combinations all spark simultaneously at high power. At high power, if one is too far advanced, one or more cylinders may tip into detonation. If one is grossly retarded, the engine may not make rated power.

All the advanced timing stuff happens at low power.
 
It's Getting Clearer

Thanks everyone for this discussion. I read every post I encounter about electronic ignition closely. The EI, magneto, spark advance, MP relationship makes sense to me now.
I love some VAF. :D
 
All the advanced timing stuff happens at low power

OK I see. So, compared to a standard mechanical mag, these mags provide a RETARDED timing. Whereas a standard mag is fixed at an advanced time, these mags can time the spark at less than or equal to that (as appropriate).

The nomenclature used had me confused. They should call their system "Advanced Retarded Timing". OK, maybe not..:D
 
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OK I see. So, compared to a standard mechanical mag, these mags provide a RETARDED timing. Whereas a standard mag is fixed at an advanced time, these mags can time the spark at less than or equal to that (as appropriate).

The nomenclature used had me confused. They should call their system "Advanced Retarded Timing". OK, maybe not..:D

Most EI's provide the same timing as a standard magneto at high power, plus advanced timing with decreased manifold pressure. Some have the option of modifying or eliminating the advance function. Any EI, with or without an advance function, provides easier starting, generally better idle, and the ability to run leaner mixtures.
 
plus advanced timing with decreased manifold pressure.

The phrase "advanced timing" used here means the system is retarding (not advancing) the timing with decreased manifold pressure. Right?

If it is said that the system is providing "advanced timing" with lower power, one would read that to mean it advances the timing, when apparently it's doing exactly the opposite of that.
 
The phrase "advanced timing" used here means the system is retarding (not advancing) the timing with decreased manifold pressure. Right?

If it is said that the system is providing "advanced timing" with lower power, one would read that to mean it advances the timing, when apparently it's doing exactly the opposite of that.


In this context, lower MP/ higher altitude advances the timing compared to a fixed magneto. So yes, "advanced timing" means exactly that - the plug is firing earlier in the piston stroke/crank rotation.
 
Confusing throttle with MP

The phrase "advanced timing" used here means the system is retarding (not advancing) the timing with decreased manifold pressure. Right?

If it is said that the system is providing "advanced timing" with lower power, one would read that to mean it advances the timing, when apparently it's doing exactly the opposite of that.

Jon,
I think you?re confusing throttle and MP. During cruise at 10,000? with wide open throttle and leaned out, my manifold pressure is low and even with high rpms my power output is below 60%. This is an example of where the ignition advance lives. Ignition is not retarded, it is advanced. At altitude, in cruise, leaned out is where you get the advantage of the ignition advance. As others have stated, other benefits of EI include easier starting and smoother idling.
 
Finished installing my Surefly today. Longest part of the install was getting a cotter key on the mag gear to my satisfaction. It comes with one - I was lucky to have a bag of 25 of them. Funny how the shortest items in the instruction manual usually take the longest.

Anyways, I was immediately impressed at how quickly it started, both cold and hot. It really is like starting a car. Idles smoothly much lower and I can lean it much farther on the ground. I am in fixed timing mode for now, so not sure how much the efficiency will change, but I will probably experiment with the variable timing mode eventually. I also had to move my one EIS tach input to the right magneto, but that was an easy fix.

Chris
 
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