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Lycoming EIS (SureFly)


chrixxer

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Getting rid of ozone sensitive plastic gears and their stripped teeth makes the electronic ignition interesting for me...

Along with the expect 500 hour refresh...

And getting that refresh onto different schedules... for the two mags...

Just a few side benefits I’m looking forward to some day... :)

Best regards,

-a-

 

 

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  • 4 months later...
3 hours ago, FlyingDude said:

Hey guys,

Any new pireps? What's the final verdict on electronic ignitions? Worth it or snake oil?

Cheers...

 

I’m happy with my SF.  Don’t expect to go noticeably faster, but it starts easier, runs smoother LOP, and should require less maintenance over its life.

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I’m happy with mine.  I replaced the left mag on my ‘63C, which was way past the 500 hr IRAN.  Shower of sparks is history.  I still need to get the dual-spline drive gear because the closest I could get was about 1.5 degrees ATDC.  But, it starts and runs great.  I didn’t have any unusual CHT issues before, and don’t have any now.

Depending which mag you replace, consider replacing the Bendix mag switch with the STC’d rocker switch panel.  There is a lag when switching from R through L to Both during mag checks, and if you’re not quick enough, expect a bang because the SureFly takes a millisecond to energize.  More pronounced if you do inflight mag checks.  My mag switch was shot anyway, and I didn’t have panel room for the rocker switch faceplate, so I put in a couple of mil-spec toggle switches in that dead space above the radio stack and that solved all my problems, for a fraction of the STC’d rocker switch option.  I adopted (with minor changes) a schematic I got from the RV community.  There’s several production aircraft that use toggle switches for the mags.  After discussion with my IA I did a minor mod with a logbook entry.  

Other than I don’t have a ‘key’ anymore, I don’t see a downside.  

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If you are contemplating a SureFly, contact them and find out if they are shipping the new version that avoids cutting out on 28V electrical systems without using an external power conditioner. It's supposed to have a faster boot time that eliminates the bang when switching mags also.

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1 hour ago, danad said:

Anyone saving 10% of their fuel?

Ha!  No.  I don’t think SF says that, but I have seen that somewhere... maybe electroair?  
I did notice that I got a few more knots when LOP.  This amounts to a small fuel savings in mpg.  If you pull back the mixture further (or reduce MP or RPM) until you’re cruising at your pre-SF airspeed, you might see a little fuel savings, but 10% seems high to me.  I’ve just been happy with the couple extra kts, smoothness, starting, and lack of maintenance.

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19 hours ago, PT20J said:

If you are contemplating a SureFly, contact them and find out if they are shipping the new version that avoids cutting out on 28V electrical systems without using an external power conditioner. It's supposed to have a faster boot time that eliminates the bang when switching mags also.

Skip

skip, 

i just did the lycoming EIS on my 390.  I cant say i am a huge fan.  in the air it is flawless, but I don't care for the mag checks, nor would I ever want to do an in flight mag check.  I think ill be getting the electroair switch soon to deal with the momentary stumble.  

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+1 for the button and the switches...

The Bendix switch and electronic Mags were not meant for each other... :)

As far as magic and saving fuel...

That comes with comparing best cases and worst cases....

Mooneys that are well operated are not going to show much magic in improved efficiency...

There are quite a few benefits to the stronger spark and adjustable timing that comes with some electronic mags...


PP thoughts I have read around here...

Best regards,

-a-

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  • 3 weeks later...

Good information posted in this thread.  For those of you with experience with the EIS and regular slick mags, what do you see as the PROs/CONs of getting a factory rebuilt IO360-A3B6 with either two standard mags (slick mag I'm told ship with the rebuilt engine) vs one standard and one Lycoming EIS?  I'm waiting to hear from the factory, but I assume if the EIS comes with non-variable timing set for 20 deg BTDC that the standard mag will have to be equally set, and this post thread includes mention of some performance loss from 25 to 20 deg BTDC.  Thoughts?

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The Lycoming branded SureFly (EIS) will come with fixed timing set at 20 deg BTDC. You would have to check, but I imagine that the variable advance feature is permanently disabled. So, if you want the variable advance, you might need to order the engine with Slick mags and replace one with a SureFly SIM later (perhaps after the warranty period).

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Thoughts regarding the 20 & 25°BTDC timing...

Many Mooneys were born with 25° timing...

Some got changed to 20° Timing....

25° timing is known for improved power, at the cost of higher CHTs...

Anyone that loves their JPI is comfortable with more power and accompanying CHTs...

The change to 20° timing is a safety mechanism for the average pilot...

 

Continental uses 22° BTDC timing...

If none of this makes sense, or isn’t of interest...  stay with the 20° timing... :)

Just remember... all those performance charts are based on the engine the way it was set up when the POH was written...

Going to fine wire plugs has a similar affect... the initiation of the flame front is improved with stronger spark and fine wire plugs... sort of an addition to the timing...

PP thoughts only , not a mechanic...

Best regards,

-a-

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On 4/19/2021 at 2:50 PM, danad said:

Anyone saving 10% of their fuel?

I do see that kinda fuel savings. I do a lot of cross country for work and have around 175 hours on my SF. I always run best economy when I fly above 9000 feet and see fuel burn at 7.8 at 9 and down to 6.9 at 14500. The fuel savings is very clear when I am able to pull my prop back to 2300-2400 rpms at the higher altitudes vs having to run it at 2500-2600 rpm due to the advanced timing. 

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12 hours ago, spectre6573 said:

I do see that kinda fuel savings. I do a lot of cross country for work and have around 175 hours on my SF. I always run best economy when I fly above 9000 feet and see fuel burn at 7.8 at 9 and down to 6.9 at 14500. The fuel savings is very clear when I am able to pull my prop back to 2300-2400 rpms at the higher altitudes vs having to run it at 2500-2600 rpm due to the advanced timing. 


Were you able to see about 20mpg (statute)?

Plenty depends on winds of the day...

But, when I was flying my M20C... 20mpg looked like a real possibility...

I didn’t have enough instrumentation to be very accurate about it...

Best regards,

-a-

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On 5/10/2021 at 6:39 PM, FLYFST said:

Good information posted in this thread.  For those of you with experience with the EIS and regular slick mags, what do you see as the PROs/CONs of getting a factory rebuilt IO360-A3B6 with either two standard mags (slick mag I'm told ship with the rebuilt engine) vs one standard and one Lycoming EIS?  I'm waiting to hear from the factory, but I assume if the EIS comes with non-variable timing set for 20 deg BTDC that the standard mag will have to be equally set, and this post thread includes mention of some performance loss from 25 to 20 deg BTDC.  Thoughts?

Well I just spoke with a Lycoming representative who answered my question, so I'm sharing it for the other inquiring minds in the forum.  He confirmed the IO-360-A3B6 is certified for 200 Hp using 20 degree BTDC timing, and that going to 25 BTDC is not a choice for that engine when configured with either two slick mags or one slick mag and one EIS.  It therefore appears that the issue of reduced power applies only when setting the timing at 20 deg BTDC on an engine that is certificated for 25 deg timing, such as the IO-360-A3B6D with the single dual mag.

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21 hours ago, carusoam said:


Were you able to see about 20mpg (statute)?

Plenty depends on winds of the day...

But, when I was flying my M20C... 20mpg looked like a real possibility...

I didn’t have enough instrumentation to be very accurate about it...

Best regards,

-a-

Out here in the southwest, I usually always see a 7-15knot headwind. With that, I usually see 17-18mpg from 10-12k and then from 12-14.5 I can see 20. Of course tailwinds are great and I have seen 22mpg

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11 hours ago, FLYFST said:

 

Well I just spoke with a Lycoming representative who answered my question, so I'm sharing it for the other inquiring minds in the forum.  He confirmed the IO-360-A3B6 is certified for 200 Hp using 20 degree BTDC timing, and that going to 25 BTDC is not a choice for that engine when configured with either two slick mags or one slick mag and one EIS.  It therefore appears that the issue of reduced power applies only when setting the timing at 20 deg BTDC on an engine that is certificated for 25 deg timing, such as the IO-360-A3B6D with the single dual mag.

I’m sorry, but that is incorrect. I’m not saying that someone at Lycoming didn’t tell you that, but it is not correct information based on the most current TCDS from the FAA. I discussed this issue at length with Lycoming when I purchased my factory rebuilt IO-360-A3B6 and was told that all the engines originally certificated with 25 deg BTDC timing would make rated power with 20 deg timing. I was also told that I could change the timing to 25 deg if I desired and remark the data plate.

Every textbook I have on internal combustion engine theory and the APS courseware shows that changing the timing by 5 deg should have negligible affect on max power if the original timing was set to MBT (maximum brake torque). Yet numerous people here have reported that the engines appear to have better power output with 25 deg. I cannot explain this. 

134880133_httpsrgl_faa.govRegulatory_and_Guidance_LibraryrgMakeModel.nsf0f23b12b142b0a0878625856000386e25FILE1E10_Rev29_pdf.thumb.png.883ad069b3fd29f7ea1a754e2c8f67f6.png

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On 5/12/2021 at 10:49 PM, PT20J said:

I’m sorry, but that is incorrect. I’m not saying that someone at Lycoming didn’t tell you that, but it is not correct information based on the most current TCDS from the FAA. I discussed this issue at length with Lycoming when I purchased my factory rebuilt IO-360-A3B6 and was told that all the engines originally certificated with 25 deg BTDC timing would make rated power with 20 deg timing. I was also told that I could change the timing to 25 deg if I desired and remark the data plate.

Every textbook I have on internal combustion engine theory and the APS courseware shows that changing the timing by 5 deg should have negligible affect on max power if the original timing was set to MBT (maximum brake torque). Yet numerous people here have reported that the engines appear to have better power output with 25 deg. I cannot explain this.

Really appreciate that clarification!  What Lycoming told you, ".... that all the engines originally certificated with 25 deg BTDC timing would make rated power with 20 deg timing...", is actually consistent with what I reported Lycoming told me, that the IO-360-A3B6 is certificated to produce 200 Hp with 20 deg BTDC timing.  The TCDS clearly shows that engine is certificated to use either 20 or 25 deg BTDC timing, and also shows the A3B6D is only certificated to use 25 deg BTDC timing.

Based on the TCDS, what appears to be incorrect is that using 25 deg BTDC timing is not a choice for the A3B6 engine when configured with either two slick mags or one slick mag and one EIS.  Of course if the EIS timing can not changed to use 25 deg BTDC, and assuming the Slick mag can be changed, then stating the A3B6 with the Slick mag and EIS combination cannot be used with 25 deg BTDC timing would actually appear to be correct.  It the EIS timing cannot be changed to 25 deg BTDC, would it perhaps be a better choice to the two Slick mags configuration, that can be set to 20 or 25 deg BTDC as allowed by the TCDS, instead of the Slick mag / EIS combination?  What did you use for your A3B6 factory rebuilt?

Regarding the power loss reported by some in this forum, per the TCDS and Lycoming responses to you and me, that appears to not apply for an A3B6 delivered with 20 deg BTDC timing.  What seems questionable, without providing objective data to support it, was my attribution of the power loss reported by some to using 20 deg BTDC timing on an engine certificated only for 25 deb BTDC, such as the A3B6D.

all the best!

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There are actually a couple of timings to consider when the changing the magneto timing on an engine. (Actually, there is a third -- E-gap, but that's internal to the mag itself and not normally a field adjustment). The first is the timing we are familiar with which is the timing of the mag to the engine. In the IO-360 case it is either 20 or 25 degrees BTDC. The second is the lag angle on magnetos that have an impulse coupling. Timing of 20 or 25 degrees is too advanced for starting -- it could cause kickback at cranking speeds -- so the impulse coupling incorporates a lag angle to reduce firing to about 5 deg BTDC for starting. Slick mags are available with a 15 deg lag angle allowing the base timing to be set to 20 deg. with the proper mag. The Bendix dual mag was never built with this lag angle, and that's the reason that the A3B6D is not approved for 20 deg. It's clearer form the original Lycoming Service Instruction.

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SI 1325 Timing Change for IO-360 Series Engines.pdf

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8 hours ago, PT20J said:

I believe Byron @jetdriven made pretty careful measurements on an M20J with a A3B6 with 20 and 25 deg timing. Perhaps he can summarize.

Skip

What say you Byron, any data you are willing to share?

On a related note, I asked Lycoming today about changing the EIS timing on a factory rebuilt A3B6 with a Slick Mag  and EIS combination, and the response was: "Currently there is no option to adjust the timing of the EIS system in the field. If you wanted to run your engine at 25 BTDC you would need to order a different EIS system that is set for 25 BTDC."

all the best - Hank
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