Surefly electronic ignition question

[Ragsf15e]

1 hour ago, Yetti said:

In this day and age, you would think they would have a connection to monitor the advance and display on a screen.   And of course record it with other engine data.

No doubt.  Bluetooth to my phone be real nice.

Be nice to have it adjustable less than their established max curve back to the dataplate standard advance too.

[Yetti]

3 minutes ago, Ragsf15e said:

No doubt.  Bluetooth to my phone be real nice.

Be nice to have it adjustable less than their established max curve back to the dataplate standard advance too.

I could see hardwired being more acceptable.  You would not want your buddy to retard your timing when you are drag racing him

[DXB]

On 8/15/2019 at 5:39 PM, Yetti said:

In this day and age, you would think they would have a connection to monitor the advance and display on a screen.   And of course record it with other engine data.

Surefly and electroair have boldly brought ignition timing technology into the 1980s for certified aircraft engines. Let’s not get greedy 

Edited August 18, 2019 by DXB

[ArtVandelay]

I could see hardwired being more acceptable.  You would not want your buddy to retard your timing when you are drag racing him

Most BT devices have a maximum range of 25’. So if drag racing your buddy at less than 25’, both of you have other things to worry about, like if your will and testament is up to date.

 

 

Tom

[McMooney]

On ‎8‎/‎15‎/‎2019 at 8:55 AM, Bob_Belville said:

Basic question: 

 

From the Surefly Site:

SIM4N - 4-Cylinder Non-Impulse Mag Replacement

               Replaces 4-cylinder non-impulse coupled magnetos on Lycoming & Continental engines. 4.0 lbs.

SIM4P - 4-Cylinder Impulse Coupled Mag Replacement

                The vast majority of 4-Cylinder applications will replace the impulse coupled magneto. 4.4 lbs.

 

So, what about replacing left mag with SoS (shower of sparks)? I'd assume I need the "P" but I don't want to order the wrong model.

SIM4N, sos doesn't have impulse coupled mag

[Bob_Belville]

6 hours ago, McMooney said:

SIM4N, sos doesn't have impulse coupled mag

That choice is not obvious to me. I want the EI device to be the hot one on start up to enjoy the heralded easy starting promise so I would think that means replacing the left mag, not the right one which is the non-impulse couple mag that is grounded when the ignition switch is held to the right. BICBW.  

[takair]

11 minutes ago, Bob_Belville said:

That choice is not obvious to me. I want the EI device to be the hot one on start up to enjoy the heralded easy starting promise so I would think that means replacing the left mag, not the right one which is the non-impulse couple mag that is grounded when the ignition switch is held to the right. BICBW.  

The SiM4N replaces the shower of sparks version of the magneto.  The 4N installation manual has the details.

[McMooney]

10 hours ago, Bob_Belville said:

That choice is not obvious to me. I want the EI device to be the hot one on start up to enjoy the heralded easy starting promise so I would think that means replacing the left mag, not the right one which is the non-impulse couple mag that is grounded when the ignition switch is held to the right. BICBW.  

For SOS the SIM4N is correct, you don't have an impulse coupled mag to replace. Impulse coupled mags are  used with non SOS systems.  I think Maxwell wrote something about it. 

Really, doesn't matter which mag is replaced as they both take part in the starting event.

A side benefit, when replacing the left mag,  you also get to remove the SOS system as The EI doesn't need assistance in starting of the aircraft.

with that being typed,  my IA replaced my right mag.  His thinking, In the case the SIM4N goes belly up, i'd have the SOS upon which to fall back.   

personally,  don't think id fly if I knew one of the mags wasn't working

Edited August 19, 2019 by McMooney

[ArtVandelay]

So if you have EI, why not both hot on startup, actually, even with just magnetos, what’s the reason for only 1 hot on startup?


Tom

[EricJ]

58 minutes ago, McMooney said:

Really, doesn't matter which mag is replaced as they both take part in the starting event.

With non-SOS, usually only one magneto has an impulse coupler with retarded timing for starting.   The other is disabled until the engine is running.   Usually this is done with the ignition/start switch, where the "start" connection grounds the non-impulse-coupled mag to disable it.   With something like the EI or Surefly it would make sense to have it be the starting ignition and disable the other during start.

 

 

[Andy95W]

1 hour ago, McMooney said:

 

with that being typed,  my IA replaced my right mag.  His thinking, In the case the SIM4N goes belly up, i'd have the SOS upon which to fall back.   

That's just dumb- and a little lazy.  He replaced the right magneto because it's easier to get to and work on- not to mention then he didn't have to remove the SOS box or mess with the ignition switch.

It's dumb because now you're still starting with the SOS left magneto, so you don't get the benefit of the higher power spark.  You also could have sold your left magneto for more money.  Finally, now when your 500 hour magneto inspection comes up, that'll cost you more money too.  

If he hasn't sold your right mag yet, you should consider paying him (or somebody else) to do the job right.  Sigh.

[charlesual]

With non-SOS, usually only one magneto has an impulse coupler with retarded timing for starting.   The other is disabled until the engine is running.   Usually this is done with the ignition/start switch, where the "start" connection grounds the non-impulse-coupled mag to disable it.   With something like the EI or Surefly it would make sense to have it be the starting ignition and disable the other during start.
 
 

Just to clarify. I have a non-SOS and my left magneto is impulse (Used for starting).
Questions,
If I change my non impulse right magneto with a surefly, do I need to disable the left magneto for starting somehow? Does the non-impulse surefly assist in starting?


Sent from my iPhone using Tapatalk

[McMooney]

5 hours ago, nosky2high said:

Why not remove the connection on the key switch so it starts using both mags? Does that give you the best of both worlds with the SOS left mag and right side electronic ignition? 

Just a thought, not an A&P. 

 

8 hours ago, McMooney said:

For SOS the SIM4N is correct, you don't have an impulse coupled mag to replace. Impulse coupled mags are  used with non SOS systems.  I think Maxwell wrote something about it. 

Really, doesn't matter which mag is replaced as they both take part in the starting event.

A side benefit, when replacing the left mag,  you also get to remove the SOS system as The EI doesn't need assistance in starting of the aircraft.

with that being typed,  my IA replaced my right mag.  His thinking, In the case the SIM4N goes belly up, i'd have the SOS upon which to fall back.   

personally,  don't think id fly if I knew one of the mags wasn't working

To be clear,

I was told by the IA, my plane uses both the SIM4N and the SOS to start. 

i haven't personally checked the IAs work but with it starting within 1 rotation, something must be connected right.

Edited August 19, 2019 by McMooney

[EricJ]

The STC for the Surefly should indicate how it is to be done.

 

[Andy95W]

5 hours ago, McMooney said:

 

To be clear,

I was told by the IA, my plane uses both the SIM4N and the SOS to start. 

i haven't personally checked the IAs work but with it starting within 1 rotation, something must be connected right.

Then I'm supposing he did the job right and removed the jumper that grounds the right magneto during start.  I'm glad- but I stand by my thoughts that I would rather sell the left mag/SOS and keep the simple right magneto.

[Bob_Belville]

Okay sports fans, my interest in Surefly got very serious today. (I order a SIM4N this afternoon which was in stock and has already been shipped!)

• I was very lucky that I did not get stranded in some very inconvenient airfield during our long cross country tour... the Shower of Sparks has apparently been failing and is now dead! But it got me home before dying. (On more than one occasion in hindsight I think the engine only caught because the engine was still spinning when I release the key and both mags kicked in at 25 BTC. When starting the right mag is disabled and the retarded points in the right mag get energy from the SoS.) BTW, in trouble shooting we disabled the starter and pulled the plugs that are connected to the left mag. Even though the SoS "buzz box" could be heard with the key on the spark was nearly nonexistent. 
• We figured out the difference between the 2 models of the Surefly. The units are the same except that the SIM4N has a shorter shaft than the SIM4P. The P shaft is longer because the Impulse Couple sets the mag further out from the drive gear.
• The SIM unit replaces the left mag. The timing is automatically TDC when starting (based on engine below 400 RPM) and shifts to 25 BTC (20 if that's the engine spec) once the engine RPM > 400. As I understand it, the timing remains at 25 BTC until MP is less than some value, at altitude, and can advance to about 28 BTC.   
• The unit should arrive this week... can't wait!

[carusoam]

I’m looking forward to your experience notes, Bob!

Best regards,

-a-

[J0nathan225]

10 hours ago, Bob_Belville said:

Okay sports fans, my interest in Surefly got very serious today. (I order a SIM4N this afternoon which was in stock and has already been shipped!)

• I was very lucky that I did not get stranded in some very inconvenient airfield during our long cross country tour... the Shower of Sparks has apparently been failing and is now dead! But it got me home before dying. (On more than one occasion in hindsight I think the engine only caught because the engine was still spinning when I release the key and both mags kicked in at 25 BTC. When starting the right mag is disabled and the retarded points in the right mag get energy from the SoS.) BTW, in trouble shooting we disabled the starter and pulled the plugs that are connected to the left mag. Even though the SoS "buzz box" could be heard with the key on the spark was nearly nonexistent. 
• We figured out the difference between the 2 models of the Surefly. The units are the same except that the SIM4N has a shorter shaft than the SIM4P. The P shaft is longer because the Impulse Couple sets the mag further out from the drive gear.
• The SIM unit replaces the left mag. The timing is automatically TDC when starting (based on engine below 400 RPM) and shifts to 25 BTC (20 if that's the engine spec) once the engine RPM > 400. As I understand it, the timing remains at 25 BTC until MP is less than some value, at altitude, and can advance to about 28 BTC.   
• The unit should arrive this week... can't wait!

I just messaged AGL about doing an install for me during annual (December), hope all goes well! 

[Bob_Belville]

7 minutes ago, J0nathan225 said:

I just messaged AGL about doing an install for me during annual (December), hope all goes well! 

Jon, Lynn has installed several EIs (Electroair? other?) but mine will be their first Surefly. Lynn likes what he's seen and he was able to get all our questions answered by Surefly's tech support.

[J0nathan225]

5 minutes ago, Bob_Belville said:

Jon, Lynn has installed several EIs (Electroair? other?) but mine will be their first Surefly. Lynn likes what he's seen and he was able to get all our questions answered by Surefly's tech support.

Nice, I'm excited to hear what y'all think about it. I'm about to board my flight to Seatac for the pick up of N93GG! 

[David Lloyd]

Look at all those states you get to color in!

[PT20J]

The SureFly (missing) advance curve has been bugging me, so I spoke with Jason Hutchison at SureFly. He confirmed that they removed it from the website. He said it was an oversimplification and technically incorrect. He also said that they decided for reasons he declined to elaborate on not to publish the corrected curve(s). He was pretty forthright and I didn't get the sense they are trying to hide anything. I suspect that they are tired of "experts" opining on the details of their design. OK, I get that -- I probably wouldn't get too far trying to get Subaru to send me advance curves for my Outback.

Here is what I did learn: The primary design goal of the advance is to adjust timing so that the peak pressure point (PPP) is about 13 degrees ATDC which they found to be close to the Maximum Brake Torque (MBT) angle for most engines in cruise operation. Operating at MBT gives the greatest efficiency. The use of MAP and rpm is analogous to the old auto distributors that had centrifugal and vacuum advances. At 24" MAP and above, the SureFly will be at base timing. Below 21" it will be fully advanced.

Skip

[carusoam]

It is absolutely great when an MSer makes the phone call, then reports back!

Thanks for sharing the call details, Skip!

Best regards,

-a-

[ArtVandelay]

I wonder if 28° is the maximum or is it +3° above factory specs.

Frankly I can’t get excited by +3°, especially since I can legally set timing to 22° on a 20° factory limited engine, so it’s 1°. So now it’s a question of what’s more dependable.


Tom

[Guest]

2 hours ago, ArtVandelay said:

I wonder if 28° is the maximum or is it +3° above factory specs.

Frankly I can’t get excited by +3°, especially since I can legally set timing to 22° on a 20° factory limited engine, so it’s 1°. So now it’s a question of what’s more dependable.


Tom

How do you get to use a 2 degree tolerance?  The engine data plate data doesn’t show one.

Clarence