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Thoughts on Surefly mag replacement for turbo?


jrwilson

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The Sure Fly magneto replacement was certified for the 231 with a caveat, it is only approved for fixed timing right now, not advanced timing.  I called Sure Fly tech support and they claimed they're close to approval for advanced timing and then the unit could be switched to advanced with little effort (But he is a sales guy too, so who knows the truth on that).  So the only real benefit at this point for the switch to sure fly would be easier start (Mine starts easy now) and no 500 hour mag inspection and no timing check on one mag at annual.  The unit is about $1700 and you also need a new harness and a resistor for the tach.  My mechanic said he didn't think it was worth it if you can't advance the timing. I think the lack of mag overhaul and simplicity make it maybe worth it. 

What do you guys thing?

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1) Eliminating plastic gears in a harsh environment can make some sense...

2) Flying in the FLs leads to the use of pressurized mags...

Questions I would have...

Do you have plastic gears in yours?

Is your mag pressurized?

Do you want to be first?

The up side seems to be improved reliability...

The down side not much real experience with turbo’d Mooneys... and last on the list for getting updates like variable timing...

Variable timing doesn’t make much sense for TC’d birds because they are often using high power settings.

 

It may make sense if you are coming up on a mag OH...

Makes more sense if you are good with engine monitors... and use your JPI900 often...

 

PP thoughts only, not a mechanic...

Best regards,

-a-

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Just now, jrwilson said:

And my mag is coming up for overhaul at this annual.

Then i would most definetely recommend it. Youll get some cash back from selling the old mag too. Engine will run smoother. Id also probably get the electro air starter switch, to avoid backfires on runnups. @aviatoreb just put one on his rocket. Id ask him for a pirep, since hes probably one of if not the first guys to put it on a turbo mooney.

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5 minutes ago, Niko182 said:

Then i would most definetely recommend it. Youll get some cash back from selling the old mag too. Engine will run smoother. Id also probably get the electro air starter switch, to avoid backfires on runnups. @aviatoreb just put one on his rocket. Id ask him for a pirep, since hes probably one of if not the first guys to put it on a turbo mooney.

..oh surefly starter switch - how do I do that?

E

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29 minutes ago, carusoam said:

Questions I would have...

Do you have plastic gears in yours?

Most Bendix or Slick mags have plastic gears inside.   If something is going to seize and fail, you want the failure to be in a replaceable accessory rather than inside the accessory case where the debris would go in the oil system and the rest of the gear train and might cause other failures.

That's also why vacuum pumps have plastic drives that are inspectable.   When (not so much if, but when) the vane pump fails and seizes the drive shears.   On many pumps the shear section is visible so you can see that it has failed without removing it.

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1 hour ago, jrwilson said:

The Sure Fly magneto replacement was certified for the 231 with a caveat, it is only approved for fixed timing right now, not advanced timing.  

Why do you need altitude compensating variable timing with a turbo?    The reason for variable timing is for greater efficiency during low MP operations.. How long is the turbo operated below ??(I can't find the graph on the current website).. it was like 24.5"MP. (from another thread).. I'm in the pattern at that MP. 

It also has a bad failure mode: 

From the FAQ:

Upon loss of manifold pressure input, a SIM configured for variable timing will calculate advance based upon pressure altitude. In this unlikely scenario, variable timing may result in engine detonation margins too narrow to safely operate a turbocharged aircraft at high altitudes.

*****

Looks like the M20M is now on the list... I'll have to take a look to get the better starting & LOP operations.  If this had been available 2 years ago when my left mag wrecked its points I would have put it in... will probably wait now that it runs fine and think about it at the 500hour O/H point. 

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The challenge with the plastic gears...

They chose a nylon that doesn’t do very well in the high ozone environment.

The gear teeth get too brittle and have a tendency to break off.

I don’t know if this something that should get tossed every 500hrs and people don’t recognize it...(?)

 

But if the electronic mag doesn’t have any ozone exposure issues, this would a check in the plus column.

Note on the ozone... whenever an electric spark occurs in air... ozone gets generated... so it’s ozone inside the mag that is a challenge...

PP thoughts only, not a mechanic.

Best regards,

-a-

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16 hours ago, Niko182 said:

Then i would most definetely recommend it. Youll get some cash back from selling the old mag too. Engine will run smoother. Id also probably get the electro air starter switch, to avoid backfires on runnups. @aviatoreb just put one on his rocket. Id ask him for a pirep, since hes probably one of if not the first guys to put it on a turbo mooney.

Can you - or someone else - describe in a bit more detail what you are saying?  I see no starter switch on surefly's website and also I do not understand what it is that is causing a backfire or why that would happen on run up.  And since I am now newly equipped wit the sure fly electronic ignition, I certainly want to understand if there would be some kind of secondary problem I should be avoiding.

E

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I think "the switch" is not a Surefly device but an ElectroAir one.  The idea is for separate controls for each magneto, so you avoid the slight-but-possibly-noticeable delay for when the Surefly "boots up" and actually starts sparking.  As in, make sure there is no time with no spark, which can happen when turning the key back and forth.

See this post (better yet whole thread) for where I got the above.

Edited by tmo
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As per the SureFly FAQ:
Why does the engine stumble during mag check:

On some aircraft there is a slight engine stumble when doing a mag check. We have discovered that some mag switches actually ground both ignition systems in the transition between Left and Right positions. The SureFly Ignition Module requires a few milliseconds to power up after being tuned on. This only occurs on a small percentage of aircraft. If you are one of the lucky ones, stay tuned as we are working on a solution.

SureFly could handle it by having a timer before it shuts "off" on grounding to allow for the pass through.   

An alternate would be to have a push button to test the problematic mag.   So that you would use the key switch to test first position only  and then go back to both.  Then you push the button that grounds the other mag.  After that second test, you release the button, and system goes back to both without having a dual grounding issue.   That would also keep the "put the keys on the dash to know the mags are grounded" group happy.  Somehow all of the twin flyers don't seem to need that. 

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8 hours ago, aviatoreb said:

Can you - or someone else - describe in a bit more detail what you are saying?  I see no starter switch on surefly's website and also I do not understand what it is that is causing a backfire or why that would happen on run up.  And since I am now newly equipped wit the sure fly electronic ignition, I certainly want to understand if there would be some kind of secondary problem I should be avoiding.

E

I have a Surefly on an IO360.  Its real nice.  Better LOP operation, starts really easy.  The “afterfire” thing is real though, at least on mine.  During runup at 1700rpm it’s just a slight skip.  I did a LOP mag check at 11,000’ and 65% power... it was a loud bang.  I also got a somewhat smaller bang when I checked the key off position to make sure the engine would shut down at idle power.

 The issue is that the Surefly takes like 5 ms to start sparking after being shutdown.  When you’re checking the Surefly, then go back to both, all is well, there is always a mag firing.  When you check the Right mag and then cycle back to both, you pass through the “Surefly only” position on the ignition and it takes 5ms before you get a spark.  Depending on power setting, it may be a bang.  This is with a traditional ignition switch.

I do like it though.  I need to do a few more flights and collect more data, but high altitude LOP seems to have a measurable reduction in ff or increase in a couple knots.

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I got this reply from surefly today.

The standard mag switch should work just fine. The problem comes from the temporary grounding of both magnetos while rotating the switch. We have seen people have success with changing slower or faster during a normal mag check. 
 
The best improvement we have seen is just changing up the way you check the magnetos. For example: bring the engine up to your mag check RPM, and turn the switch one click to the left, and watch it drop. Turn it one click to the left again, and watch it drop. Then bring the throttle back to idle before rotating the key back to both. 

 

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If there is residual spark - a phrase I don't quite understand what that means - for up to 5 minutes?!  Does that mean that the prop/engine is still hot after shut down with the key removed and I ask regarding prop ground ops safety if I touch the prop during pushing the airplane back into the hangar?

E

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1 hour ago, aviatoreb said:

I got this reply from surefly today.

The standard mag switch should work just fine. The problem comes from the temporary grounding of both magnetos while rotating the switch. We have seen people have success with changing slower or faster during a normal mag check. 
 
The best improvement we have seen is just changing up the way you check the magnetos. For example: bring the engine up to your mag check RPM, and turn the switch one click to the left, and watch it drop. Turn it one click to the left again, and watch it drop. Then bring the throttle back to idle before rotating the key back to both. 

 

At least for me, run up hasn’t been an issue.  It does skip a beat, but no bang, noise, vibration, nothing.

When I did the LOP mag check at 65% power, that was more exciting.  Next time I’ll try their technique of pulling power after checking the second mag.

For some reason, the shutdown check also got a bang.  I’ll try to see if I can find something that works for that too.

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Controlling the mags with independent switches is a good solution.  However, is anyone concerned that this option would delete the key to the mag switch?  Is the door key by itself enough protection?  Granted, for someone hell bent on theft, the mag switch key really isn’t that much of a deterrent.  Bonus, I’m contemplating no more fishing in my jeans pocket for the mag switch key after I’ve got my seat belt fastened.

I’ve only ground-run my Surefly, (replaced the left mag) and experienced the lapse during mag checks.  No afterfire.  I ran out of travel to get to TDC and didn’t want to rotate the drive gear 180 degrees per the install instructions.  I ended up about 1.6 degrees after TDC.  I called Surefly and they said it‘s fine... and they’re considering expanding the adjustment slot to allow another few degrees rotation.

I found that if I move the mag switch quickly from right, through left, and back to both, the lapse was imperceptible.  Sure runs smooth, though.  Can’t wait to get the annual done and fly it.

tom

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1 hour ago, Ragsf15e said:

At least for me, run up hasn’t been an issue.  It does skip a beat, but no bang, noise, vibration, nothing.

When I did the LOP mag check at 65% power, that was more exciting.  Next time I’ll try their technique of pulling power after checking the second mag.

For some reason, the shutdown check also got a bang.  I’ll try to see if I can find something that works for that too.


expect what is going on during the run up...

the moment When the electronic mag doesn’t fire, fuel goes directly to the muffler...

Engine cold, exhaust cold... no bang.

 

Doing the same thing with a hot exhaust... the small amount of fuel ignites itself on the hot parts of the exhaust...

Takes heating the exhaust to be about 500°F... generally glowing lightly red when hot...

Pulling the throttle back between switch changes will put less fuel down the pipe...

 

I am more of a fan of testing the single mag and returning to both each time...

But, a deeper test of the mags is required because the old ones just stink that much...

The independent switches allow going to both without passing through the other single mag...

 

To get a better view of this challenge with the existing ignition switch...

we should/need to put a chart together...  charting each switch position, and what it connects, and what the side effects are for the delay of ignition...

Exhaust parts can get expensive... they can break easily as they age... CO poisoning is always a concern...

So bangs in the muffler are not good... good to find a way to avoid them...

Did anyone mention pulling the mixture back some, when making the switch, the same way they mentioned pulling the throttle back... it would reduce some of the excess fuel that is going to the muffler.

PP thoughts only, not a mechanic...

Best regards,

-a-

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Plenty of concern regarding the ‘no key’ situation...

Hot mags are dangerous...

We usually leave the keys on the glare shield to indicate the mags are at least switched off...

There is still enough concern for accidental hot mags, broken ground wires....

Without the key, anyone can turn the mag on and forget about it...

 

PP thoughts about stuff I have read around here...

Best regards,

-a-

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1 hour ago, 47U said:

Controlling the mags with independent switches is a good solution.  However, is anyone concerned that this option would delete the key to the mag switch?  Is the door key by itself enough protection?  Granted, for someone hell bent on theft, the mag switch key really isn’t that much of a deterrent.  Bonus, I’m contemplating no more fishing in my jeans pocket for the mag switch key after I’ve got my seat belt fastened.

I’ve only ground-run my Surefly, (replaced the left mag) and experienced the lapse during mag checks.  No afterfire.  I ran out of travel to get to TDC and didn’t want to rotate the drive gear 180 degrees per the install instructions.  I ended up about 1.6 degrees after TDC.  I called Surefly and they said it‘s fine... and they’re considering expanding the adjustment slot to allow another few degrees rotation.

I found that if I move the mag switch quickly from right, through left, and back to both, the lapse was imperceptible.  Sure runs smooth, though.  Can’t wait to get the annual done and fly it.

tom

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6167F2F0-C0EC-4563-8D06-2445DB97E5EB.jpeg

Yeah I think you’ll like it.  Smooth running, real easy starting, and LOP definitely seems smoother and easier.

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I went flying again today.  With the new surefly fitted to my Mooney Rocket TSIO520NB.  Second flight now.  It is a tad bit faster.  2 knots maybe 3.  But that is always hard to say for sure as there is that much fluctuation from one day to the next depending on atmospheric conditions.

But without a doubt I can for sure say:

-starts almost like a car now - just turns right on no fuss.

-its smoother in idle, smoother in cruise (and with six cylinders and a 4 blade prop it was already very smooth and  I would have said its not possible it could get smoother - but it did).

-and now it seems to run lean of peak MUCH better.  I still need to do more testing but early return it is very smooth LOP where it was not quite sufficiently smooth lop before - I only tested it today at low power settings as before I was TIT limited to run LOP at anything more than about 60% and also not quite perfectly smooth but now its very cool in egt, tit, cht, and smooth - so ...I need to try out some higher settings and convince myself that wasn't a fluke of the day.  But this is exciting and could well save a massive amount of fuel.

-rop everything is cooler - egt, tit, and cht so I was running about .4-.5 lower fuel settings at same power settings I am used to ROP.  Which are generally 65% or 72%, formerly 18gph and 20gph.

BTW I also put an overhauled mag (it was time) at the same time as the new surefly mag.  SO the whole ignition system is very peppy now.

So far, VERY happy.

 

Edited by aviatoreb
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