I see the Emag 200 series (for 6 cylinder engines) finally seems to be in production, at long last.

For those who aren't familiar, the Emag is an electric magneto, fully self-contained with almost all the same benefits at EFI and a magneto wrapped into one - no dependency on the ships batteries, but variable timing, manual spark advance control, etc. read here:
http://www.emagair.com/

I think this is an exciting looking product from the advertising, I like the benefits EFI, but dislike the idea of being dependant on my batteries in the backcountry (or over water for that matter).

I am keen to hear from anyone who knows about the Emag 200 or is using them.

I have been told they've been working toward this product for about 7-8 years now, so hopefully the have all the bugs well and truly worked out by now. But nothing beats first-hand experience.

I'm planning on installing them in my Bearhawk but probably a year away.

Battson wrote:http://www.emagair.com/

I have been told they've been working toward this product for about 7-8 years now, so hopefully the have all the bugs well and truly worked out by now.

Sigh,

Three years in a row I have contacted the EMag Ignitions guy about his new 6 cylinder version. Every time, the answer is "place your order now if you like, we're one month away from production". He's said that same thing every time, for 3 years running now.

It looks like a really great product, and I would love to run them on my engine, but it's really hard to trust a company which behaves like this.

I feel for all the people who've put down deposits.

These are available for you right now for 6 cylinders but I have to wait for certification:

http://www.surefly.aero

Click on the products tab and the 6 cyl version is listed below the 4 cyl.

I will be putting one of these on the Maule as soon as it is legal.

But it appears that the Surefly system does not give you the full power and economy benefits of an electronic system, because it is limited to the manufacturer's maximum FIXED timing setting.

The EI systems that modulate the ignition timing to the best possible VARIABLE setting based on manifold pressure RPM, knock sensors, etc. will increase the performance and economy of the engine whenever the conditions will allow it.

In low-power cruise conditions, an advanced variable electronic ignition will allow the pilot to lean the mixture aggressively to take advantage of a greatly advanced spark.... a level of timing advance that is not possible or safe to run at some other power settings (like takeoff/climb).

This is how guys like Klaus Savier (and others) achieve unbelievably low fuel burn and/or very high cruise speeds. The modified O-200 engine in Klaus' famous Vari-EZ "The Delaminator" uses less than three gallons an hour in his "hyper-lean" long range cruise configuration.

The high cruise speed he gets is irrelevant in this discussion; nobody's back country airplane will ever have the low drag of a Vari-EZ. But reducing fuel burn is probably a huge deal in areas where there is a long distance between fuel, even to people flying slow draggy bushplanes.

DeltaRomeo wrote:These are available for you right now for 6 cylinders but I have to wait for certification:

http://www.surefly.aero

Click on the products tab and the 6 cyl version is listed below the 4 cyl.

I will be putting one of these on the Maule as soon as it is legal.

Good man, thanks for the suggestion.

EZFlap wrote:But it appears that the Surefly system does not give you the full power and economy benefits of an electronic system, because it is limited to the manufacturer's maximum FIXED timing setting.

It looks to me like this is a variable ignition timing system...?

My key concern is that the system appears to have no internal spark generating source - it relies on the battery I suppose. They recommend only installing one unit.

Does anyone know if they are 12V or 24V, or if they don't care?

I think I will install one / two..... I am sick of waiting for Emag to sort their business out.

Battson wrote:

EZFlap wrote:But it appears that the Surefly system does not give you the full power and economy benefits of an electronic system, because it is limited to the manufacturer's maximum FIXED timing setting.

It looks to me like this is a variable ignition timing system...?

My key concern is that the system appears to have no internal spark generating source - it relies on the battery I suppose. They recommend only installing one unit.

EZ, I almost posted the same thing this morning but I had to run out the door for work.

They say multiple times that they advance spark "up to the manufacturer's recommended" or something like that. For my Lycoming O-320 that's only 25 degrees Before Top Dead Center (BTDC).

Ignition timing is all about timing the sharp rise in cylinder pressure to the moment that the piston starts its downward travel. If you time it too soon (such as before the piston is fully up, or when the piston is in it's dwell at the top of the cylinder) you can cause mechanical breakage. This is because you're trying to force a mechanical travel that isn't in a position to move. However, if you time it too late you merely lose efficiency. If the piston is well on its way down when the peak pressure hits then you've wasted the top half of the downward travel and you'll likely expel a bunch of unused expanding gas and heat through the exhaust pipe, but there's almost no chance for damage. Most engine manufacturers err on the side of lesser efficiency and I don't blame them one bit for that.

As the air/fuel mass in the cylinder is increased (read as, increasing MAP at steady RPM), the mixture will burn faster and requires more retard to maintain peak cylinder pressures in time with piston travel. As you get closer and closer to WOT, you require less and less timing advance to keep the peak cylinder pressures timed to the piston's downward travel. As the air/fuel mass in the cylinder is decreased (read as, decreasing MAP at steady RPM), the mixture burns more slowly and requires MORE advance to keep timing optimal for efficiency.

The timing maps I built for my LS1 (man, I miss that Trans Am) had a maximum WOT advance of 28 degrees BTDC, but at part throttle cruising was anywhere from 30 to 40 degrees BTDC. I built it carefully, using the very sensitive knock sensors to ensure I wasn't timing too early, and that car ran REAL good while still turning out 30+ mpg on the highway.

Back to airplanes, the P-Mag (if set to a 20 degree BTDC base setting) uses up to 35 degrees BTDC in their "stock" timing table for part throttle - as you increase MAP that retards back to the base setting, or 20 degrees BTDC in this case. That's where you're going to grab part throttle performance. If your electronic ignition only advances as much as your fixed timing mags do, then all you're going to see is potentially increased reliability from fewer moving pieces and possibly better WOT performance from hotter sparks and longer dwell times. Part throttle will see some increased benefits from hotter sparks and longer dwell times but not to the same extent as more advance would give you.

I'm sure that the company in question here would agree with me, but argue that certification was WAY cheaper this way - I'd have to agree with them there, too.

Maybe that is only for certified installs? They go up to 38 degrees BTDC:




https://media.wix.com/ugd/712b87_19a81ce5b1eb45f3b07af440a99b37e8.pdf

Battson wrote:?

Maybe that is only for certified installs? They go up to 38 degrees BTDC:


https://media.wix.com/ugd/712b87_19a81ce5b1eb45f3b07af440a99b37e8.pdf

I wasn't able to find a different "EXP" part number... I think that's a function of whatever the engine's max fixed timing is from the manufacturer.

Read this: http://www.aviationconsumer.com/issues/ ... 004-1.html

Specifically, where they compare to the Electroaire.

They say the grey line is the manufacturer's recommended fixed timing, and they retard it from there. Except for start of course.

I've had a read.

I get they don't offer "more power" from the base engine, but the Emag doesn't do that either, I think?

I guess the main benefit is adjusting the timing during the lower power cruise settings, which results in more fuel efficiency. That is what I like about them. They say about 10% fuel savings, according to the Emag people. The products (SIM and Emag) are largely the same from what I can tell, apart from the Emag generates it's own power and doesn't require a backup system. Please correct me if I am wrong.

CamTom12 wrote:I wasn't able to find a different "EXP" part number... I think that's a function of whatever the engine's max fixed timing is from the manufacturer.

Found the answer - they have switches on the back to set it to fixed, variable, turbo, 22*, 23*, 24*, 25*, 26*, etc. - whatever your engine has / needs.

On an experimental install, you could select more aggressive settings at your own risk.

Battson wrote:

CamTom12 wrote:I wasn't able to find a different "EXP" part number... I think that's a function of whatever the engine's max fixed timing is from the manufacturer.

Found the answer - they have switches on the back to set it to fixed, variable, turbo, 22*, 23*, 24*, 25*, 26*, etc. - whatever your engine has / needs.

On an experimental install, you could select more aggressive settings at your own risk.

Ahhh... Makes way more sense now.

Well, my above post stands true, except the last 3 sentences! Good find!

Battson wrote:

CamTom12 wrote:I wasn't able to find a different "EXP" part number... I think that's a function of whatever the engine's max fixed timing is from the manufacturer.

Found the answer - they have switches on the back to set it to fixed, variable, turbo, 22*, 23*, 24*, 25*, 26*, etc. - whatever your engine has / needs.

On an experimental install, you could select more aggressive settings at your own risk.

Do they have a MAP input or just increase advance with RPM?

They have a MAP input too.

I don't know much about EI, but I am learning fast today. We're going to make the change.

I've got a P-mag myself. I wish I could give you a pirep but unfortunately it's still in the box and will likely be until my annual condition inspection next month...

Battson, don't forget that Light Speed Engineering has very high capability and experience with this stuff. They may offer what you need right now. He was one of the earliest and most successful of all the EI developers, and you simply cannot minimize the value that 30 years of screwing with this stuff adds.

Under appropriate conditions, Lycoming suggests a maximum of 38º advance for their engines. The reason our aircraft are set to 25º is because the magnetos operate at a fixed timing point and under certain performance conditions 38º would be destructive. Magnetos fixed timing points are a compromise for the entire performance envelope of the engine. Electronic ignitions allow for a dynamic firing point based on inputs from manifold pressure and engine rpm. Electronic ignition maps account for the moving threshold of peak cylinders pressures under different operating conditions whereas magnetos cannot.

DeltaRomeo wrote:Lycoming suggests a maximum of 38º advance for their engines.

Under what conditions does Lycoming suggest 38 degrees of advance? I can't imagine their corporate lawyers and insurance company would ever allow that number to be released for any reason. Lycoming has had their cherry popped in court more than a few times.

EZFlap wrote:

DeltaRomeo wrote:Lycoming suggests a maximum of 38º advance for their engines.

Under what conditions does Lycoming suggest 38 degrees of advance?

Not during WOT at high MAP. That would just be silly.