Dual mag future

[tpavlusik]

I am hearing that Bendix is talking about stoping the support for the dual mags. Can anyone elaborate on this?

Regards,

T. 

[EricJ]

41 minutes ago, tpavlusik said:

I am hearing that Bendix is talking about stoping the support for the dual mags. Can anyone elaborate on this?

Regards,

T. 

They stopped a long time ago.   Kelly Aerospace supports them now.   They just went through mine for a 500 hour inspection.   They also do overhauls and will sell new stuff (they make parts).

[tpavlusik]

Thanks Eric

[tpavlusik]

Do you know what the extra cost may be to change the accessory case and gears to install two magnetos at OH time?

[OR75]

9 minutes ago, EricJ said:

They stopped a long time ago.   Kelly Aerospace supports them now.   They just went through mine for a 500 hour inspection.   They also do overhauls and will sell new stuff (they make parts).

how much does a 500h inspection cost ?

  

[EricJ]

32 minutes ago, OR75 said:

how much does a 500h inspection cost ?

  

IIRC the basic inspection was $650 or something like that, which includes all the new bearings, points, and condensers that they change during the inspection.   Mine wound up getting nearly everything replaced, and I got a new lid and harness, and the whole thing was about $2200.    That's not bad for essentially replacing both sides of the ignition system, imho.    It's essentially a new unit.

 

40 minutes ago, tpavlusik said:

Do you know what the extra cost may be to change the accessory case and gears to install two magnetos at OH time?

Mine got pretty much everything changed out:   new gears, coils, block, condensers, plus all the bearings, points, etc., that they change anyway.   The case was cleaned and repainted and got a new data plate.   The invoice was $2262 plus shipping, $600 of which was for a new lid and harness.   The invoice says gears are $134/ea.

Edit:  Oops, read that wrong.   I thought you were asking about the magneto case and gears.    Also, I don't recall at the moment, but iirc there are more differences in the dual mag engine than the accessory case and gears.   My recollection is that it is not a practical change except at overhaul.

Edited May 10, 2021 by EricJ

[A64Pilot]

1 hour ago, tpavlusik said:

Do you know what the extra cost may be to change the accessory case and gears to install two magnetos at OH time?

I know your talking about modifying the engine to accept separate magnetos.

However, why do that? I believe the only failure that could take out the dual mag that didn't take out independent ones is the failure of the driveshaft, and I have never heard of that occurring.

I don’t believe there is a failure mode of the accy gearbox that doesn’t take the whole thing down.

‘I believe there may be an electronic alternative for the dual mag, I don’t know anything about it, but I had rather have dual electronic ignitions in one box than dual independent magnetos myself, mostly to get away from the 500 hour maintenance requirement, and if done correctly a much hotter spark, although a higher amp ignition does increase wear on the spark plugs, it out to enable smoother LOP.

Maybe one day we will have dual electronic ignitions triggered off of a crankshaft sensor? Shouldn’t be hard to do, but can you make money with it?

Edited May 10, 2021 by A64Pilot

[KSMooniac]

Electroair finally has their dual electronic D3000 replacement available now. They started taking orders at Sun n Fun. I believe it requires a second alternator, so that means we'll have to ditch the vacuum pump to add one... Which is a great idea to add redundancy and delete the old vacuum instruments.

Sent from my LM-V405 using Tapatalk

[mooniac15u]

3 hours ago, A64Pilot said:

I know your talking about modifying the engine to accept separate magnetos.

However, why do that? I believe the only failure that could take out the dual mag that didn't take out independent ones is the failure of the driveshaft, and I have never heard of that occurring.

I don’t believe there is a failure mode of the accy gearbox that doesn’t take the whole thing down.

‘I believe there may be an electronic alternative for the dual mag, I don’t know anything about it, but I had rather have dual electronic ignitions in one box than dual independent magnetos myself, mostly to get away from the 500 hour maintenance requirement, and if done correctly a much hotter spark, although a higher amp ignition does increase wear on the spark plugs, it out to enable smoother LOP.

Maybe one day we will have dual electronic ignitions triggered off of a crankshaft sensor? Shouldn’t be hard to do, but can you make money with it?

There is a serious risk of failure of the dual magneto if not mounted correctly.

https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgSAIB.nsf/0/1c2b04ce0081a3ff8625786400532072/$FILE/NE-08-26R3.pdf

 

[flyboy0681]

3 hours ago, OR75 said:

how much does a 500h inspection cost ?

  

Mine was just overhauled last week. Cost was $1,900.

[N201MKTurbo]

3 hours ago, EricJ said:

IIRC the basic inspection was $650 or something like that, which includes all the new bearings, points, and condensers that they change during the inspection.   Mine wound up getting nearly everything replaced, and I got a new lid and harness, and the whole thing was about $2200.    That's not bad for essentially replacing both sides of the ignition system, imho.    It's essentially a new unit.

 

Mine got pretty much everything changed out:   new gears, coils, block, condensers, plus all the bearings, points, etc., that they change anyway.   The case was cleaned and repainted and got a new data plate.   The invoice was $2262 plus shipping, $600 of which was for a new lid and harness.   The invoice says gears are $134/ea.

Edit:  Oops, read that wrong.   I thought you were asking about the magneto case and gears.    Also, I don't recall at the moment, but iirc there are more differences in the dual mag engine than the accessory case and gears.   My recollection is that it is not a practical change except at overhaul.

I got my last harness from KRN. It was a new old stock Continental harness. It has been a great harness. I paid $270 for it and they didn't even want the old lid back, so now I have a spare lid.

[tpavlusik]

I do not have a Mooney yet. Just doing research before I get it. There are a couple of points that I have learned about the D magneto. 1.  Magneto clamp. There were instances where the clamp got loose. Single housing, single timing for both mags. Shaft snd coupling a Single point of failure for both mags. Finally with two mags you can install one electronic. Which I hear can save some fuel. Again, I am not speaking from experience. This is just information that I found out from different sources. So real hand on information is appreciated. 

[PT20J]

4 hours ago, tpavlusik said:

Do you know what the extra cost may be to change the accessory case and gears to install two magnetos at OH time?

You cannot do this. The IO-360-A3B6D and the -A3B6 have a lot of parts differences -- it's not just the accessory case. You can turn in a A3B6D core for a factory rebuilt A3B6 from Lycoming.

Properly mounted and maintained, the dual mag has proved reliable. I would not factor that into a purchasing decision. However, it makes sense to trade out the A3B6D for an A3B6 at overhaul time which is what I did to get an engine with the greatest parts commonality, options for electronic mags, and roller lifters.

Skip

 

[Tim Jodice]

5 hours ago, KSMooniac said:

Electroair finally has their dual electronic D3000 replacement available now. They started taking orders at Sun n Fun. I believe it requires a second alternator, so that means we'll have to ditch the vacuum pump to add one... Which is a great idea to add redundancy and delete the old vacuum instruments.

Sent from my LM-V405 using Tapatalk
 

Or a second battery that it's sole purpose is to feed one system. No manual override to tap in to it to run other equipment. The battery needs to be sized that it lasts longer than full fuel lasts. 

[A64Pilot]

2 hours ago, mooniac15u said:

There is a serious risk of failure of the dual magneto if not mounted correctly.

https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgSAIB.nsf/0/1c2b04ce0081a3ff8625786400532072/$FILE/NE-08-26R3.pdf

 

You could make that statement about most anything. But now that it’s highlighted, it’s easy to manage. Anything will fail if it falls off.

I had a dual mag on my 540 and kind of liked it, easy to time, better starts as both mags are firing and just send it in to an expert every 500 hours and that’s it.

‘Oddly “hot starts” on my dual mag motor are ridiculously simple, full rich, no priming and turn the key and it starts like a car. No flooded starts?

Edited May 10, 2021 by A64Pilot

[A64Pilot]

2 hours ago, PT20J said:

You cannot do this. The IO-360-A3B6D and the -A3B6 have a lot of parts differences -- it's not just the accessory case. You can turn in a A3B6D core for a factory rebuilt A3B6 from Lycoming.

Properly mounted and maintained, the dual mag has proved reliable. I would not factor that into a purchasing decision. However, it makes sense to trade out the A3B6D for an A3B6 at overhaul time which is what I did to get an engine with the greatest parts commonality, options for electronic mags, and roller lifters.

Skip

 

I have read but cannot confirm that if you buy a zero time motor from Lycoming, they will sell you one for two magnetos for the same cost as a single. Assumption is your buying new mags and harnesses?

[A64Pilot]

8 minutes ago, Tim Jodice said:

Or a second battery that it's sole purpose is to feed one system. No manual override to tap in to it to run other equipment. The battery needs to be sized that it lasts longer than full fuel lasts. 

I hope so because a motor cycle battery would do that, add a diode so it can’t be drained by the factory battery and your done. I bet it could even have an internal Li-ion just like the modern artificial horizons etc do now.

I used to road race motorcycles, we would power the ignition systems off of a small battery and it would last all weekend easy, four cylinder engine and it was wasted spark so it fired twice as often as necessary.

[Guest]

Champion isn’t exactly giving away new Slick magnetos and harnesses these days.  There’s nothing wrong with a D3000 magneto, just maintain it.

Clarence 

[PT20J]

My factory rebuilt came with 2 new slicks. I pulled them both at a bit over 200 hrs. The E-gap had shifted on the right mag and and I was getting 200+ mag drops at run up. I pulled the left mag because it was a convenient time to do the impulse coupling rivet SB. 

In 7 years I never had any problems with my D3000. 

Skip

[PT20J]

50 minutes ago, A64Pilot said:

I have read but cannot confirm that if you buy a zero time motor from Lycoming, they will sell you one for two magnetos for the same cost as a single. Assumption is your buying new mags and harnesses?

Actually, when I bought mine they gave me a discount to swap out a A3B6D for an A3B6. The dual mag 360  never really took off except on Mooneys and Cardinals. Lycoming kind of wishes they would go away. That is not to say that Lycoming won’t continue to support them. But because they have less parts commonality with other IO-360 variants, they may ultimately cost more to maintain. At least that’s the impression I got from the Lycoming field rep when I discussed it with him.

Skip

[toto]

2 hours ago, tpavlusik said:

I do not have a Mooney yet. Just doing research before I get it. There are a couple of points that I have learned about the D magneto. 1.  Magneto clamp. There were instances where the clamp got loose. Single housing, single timing for both mags. Shaft snd coupling a Single point of failure for both mags. Finally with two mags you can install one electronic. Which I hear can save some fuel. Again, I am not speaking from experience. This is just information that I found out from different sources. So real hand on information is appreciated. 

I seriously would not let this be a deciding factor in purchasing an airplane.

You've identified the data points that make people fearful of the dual mags, but as others have said, they rarely cause problems.  This is a sideshow in the "things that will kill you" circus - the main act is CFIT and continued VFR into IMC.  I'd be far more worried about expenses due to deferred maintenance than a dual mag falling off the airplane.

Add it to your "things to think about at overhaul time" spreadsheet and don't stress about it 

[toto]

3 hours ago, tpavlusik said:

Finally with two mags you can install one electronic.

As @KSMooniacmentioned above, you can now get a certified electronic ignition from Electroair.

[Guest]

3 hours ago, tpavlusik said:

I do not have a Mooney yet. Just doing research before I get it. There are a couple of points that I have learned about the D magneto. 1.  Magneto clamp. There were instances where the clamp got loose. Single housing, single timing for both mags. Shaft snd coupling a Single point of failure for both mags. Finally with two mags you can install one electronic. Which I hear can save some fuel. Again, I am not speaking from experience. This is just information that I found out from different sources. So real hand on information is appreciated. 

I wouldn’t turn down a good Mooney J model just because it has a dual magneto.  There is an S/I from Lycoming which calls out for new clamps.  Hire a maintainer with complete manuals for the engine and airframe and a certified torque wrench.  I’ve seen more independent mags fall off than dual mags in almost 40 years of maintenance.

Clarence

[jaylw314]

2 minutes ago, PT20J said:

My factory rebuilt came with 2 new slicks. I pulled them both at a bit over 200 hrs. The E-gap had shifted on the right mag and and I was getting 200+ mag drops at run up. I pulled the left mag because it was a convenient time to do the impulse coupling rivet SB. 

In 7 years I never had any problems with my D3000. 

Skip

Yeah, I had a Lycoming rebuilt IO-360 with two slick mags, and the left one had to be IRAN'd and the e-gap readjusted at about 200 hours.  I suspect the right one needs it too, I just didn't want to do them at the same time.

The cost to IRAN with only adjusting the e-gap was about $300, so doing the same with both in a dual-mag seems costing around $600 seems to make sense.

@M20Doc and other mechanics can speak more to this, but I don't think there has ever actually been a dual-mag drive shaft failure?  It's the mounting issue that's the bugaboo, right?

[Guest]

I’ve seen more issues with mags coming loose due to improper installation, obsolete clamps, re used lock washers, wrong gaskets etc.  I’ve never experienced shaft failure on a D3000.

Clarence