Mag 500hr inspection or Surefly?

[sleeper-319]

I'm at mag 500 hour... first time hitting this number for me as an owner, and wondering of the Surefly ignition is worth it.  I've read a few threads, but they all kind drift into plane specific discussion. In general terms... are they worth the price? Are they as reliable as claimed?

I have an 87 M20J with an IO-360 A3B6 (trophy 212 mod stc, so separate slick mags). What questions should I be asking? Any reason not to do the Surefly? Pireps?  appreciate any wisdom y'all can share. Thanks. 

edit:  forgot to mention I have Garmin EIS, and there's a surefly "does it work with Garmin EIS FAQ item that says: "Yes! You will need to have a magnetic pickup installed in the remaining magneto or install a TACH2 signal converter to make a SIM compatible. Please call SureFly to discuss the installation." I get what that means technically, but not in terms of price or installation time. Is installing a magnetic pickup trivial if I'm having the non-impule-coupled one overhauled at the same time?

 

Edited August 7, 2023 by sleeper-319

[McMooney]

I'm a fan, my surefly has worked perfectly from day 1.   I'm so happy with mine, i'm going dual at my next annual.

[sleeper-319]

27 minutes ago, McMooney said:

 I'm so happy with mine...

What benefits are you seeing relative to the claims?

[McMooney]

47 minutes ago, sleeper-319 said:

What benefits are you seeing relative to the claims?

so it runs further lop than before and smoother at the original settings.

starts better, not sure how that works as i have a shower of sparks but properly primed it starts in about a blade maybe 2.

when flying at altitude, 8k+, she def seems peppier and burns less gas.

biggest change, No more 500hrs, hopefully, knock on wood, fingers crossed, etc...

[Ragsf15e]

1 hour ago, sleeper-319 said:

What benefits are you seeing relative to the claims?

I have one on my F model installed right after they were approved.  I would do it again, however, I personally wouldn’t do both mags, only one, and do the left (starting) mag, not the right one.  It will start easier, but not dramatically easier than a well set up engine.  It has been totally maintenance free (k.o.w).  There is some measurable improvement in speed or fuel burn at higher altitudes , especially lean of peak, but it’s maybe 1 or 2 knots, so barely measurable.  I posted graphs before and after installing a couple years ago.

The most difficult part of installation was removing the interior and running a power wire from the battery directly to the SF.  I did that part, my mechanic installed and setup the unit following the directions.  He said it was pretty easy.  Since then it’s been almost exactly 50rpm drop on mag check and smooth.  I did not have to do the rpm bit you mentioned as mine works perfectly with my jpi (or my mechanic moved it to the right mag).  You also might need a new harness as it requires a slick harness.  Use a “Maggie harness” if you need to buy just that half.

You may notice a slightly warmer running engine above about 8000’, but mine stays ~370chts rop or ~330chts lop and you should have even better cooling in your J.  Below about 7-8000’ it doesn’t advance the timing so no changes there.  Also, if there’s some reason you don’t like how it runs with advanced timing (I dont know why), you could set it to fixed pretty easily.

in my opinion, it’s worth it just for the maintenance free aspect, performance enhancements are a bonus.  
 

ask away.

Edited August 7, 2023 by Ragsf15e

[sleeper-319]

Thanks for the info. I have dual slick mags, so the harness shouldn't be an issue. I'll ask my a&p about the EIS thing. Hopefully it's simple.

Most of the time I'm cruising 7-11,000. I don't fly low all that much because of terrain. The engine runs well LOP as it is, and temps are indeed lower. I usually cruise at full throttle and 23 or 2400rpm, and it runs mid 330s rop and a good bit lower LOP. It starts fine (in that "you gotta know the process" way).

So the timing advance is altitude driven?

[kortopates]

1 minute ago, sleeper-319 said:

So the timing advance is altitude driven?

Only indirectly, advance is controlled by MAP, Lower MAP advances timing, so you'd be able to take advantage of it at your cruise altitude. Still though advance is not a big advantage to me but the added reliability over conventional mags. But this is a personal choice only you can make. 

[Ragsf15e]

9 minutes ago, sleeper-319 said:

Thanks for the info. I have dual slick mags, so the harness shouldn't be an issue. I'll ask my a&p about the EIS thing. Hopefully it's simple.

Most of the time I'm cruising 7-11,000. I don't fly low all that much because of terrain. The engine runs well LOP as it is, and temps are indeed lower. I usually cruise at full throttle and 23 or 2400rpm, and it runs mid 330s rop and a good bit lower LOP. It starts fine (in that "you gotta know the process" way).

So the timing advance is altitude driven?

They published a graph before it was faa approved, but the advance is driven both by map and rpm, so at your idle on the ground (lower rpm), no advance.  At cruise, with rpm above about 2000, it will begin to advance somewhere around 6-8000’ if you leave wide open throttle.  The graphs are no longer published.

I am based in Washington and fly high for terrain as well, and I definitely like it.  I did add a few knots when running lop.  Rop it’s not really that noticeable.

[Ragsf15e]

16 minutes ago, sleeper-319 said:

Thanks for the info. I have dual slick mags, so the harness shouldn't be an issue. I'll ask my a&p about the EIS thing. Hopefully it's simple.

Most of the time I'm cruising 7-11,000. I don't fly low all that much because of terrain. The engine runs well LOP as it is, and temps are indeed lower. I usually cruise at full throttle and 23 or 2400rpm, and it runs mid 330s rop and a good bit lower LOP. It starts fine (in that "you gotta know the process" way).

So the timing advance is altitude driven?

Yeah, if your plane starts fine now, it won’t change much, however, it makes your current starting process work a little better/quicker/more reliably.

[Marc_B]

I added a Surefly at 500 hr as I was having mag trouble…of course I have a pressurized mag that probably is more problematic.  Never had issues with start but easier start still. Easier hot start. Smoother with LOP and can go much deeper LOP than I could before and still run smooth. And I liked the idea of 2400 TBO without possibility of maintenance induced issues plus the added reliability of EIS. Financially for me it was a wash but was paid upfront instead of over time. Since I have a turbo no timing advance for me. 
Basically it boils down to do you want EIS or conventional mag?  Small differences with pros and cons.
Personally I like the idea of single EIS with single conventional mag. Seems best of both worlds. 

[sleeper-319]

Thanks Marc_B. btw, I was just in GXY last week. Is your profile pic somewhere around Canyonlands/Arches? 

[Marc_B]

@sleeper-319 Moab, on the Whole Enchilada. Great ride with lots of amazing views!

[philiplane]

[ArtVandelay]

I just have to wonder how the electronics of the Surefly will stand up to heat and vibration over many years.

[Ragsf15e]

6 minutes ago, ArtVandelay said:

I just have to wonder how the electronics of the Surefly will stand up to heat and vibration over many years.

Definitely a consideration, but I’ve got ~3.5 years and 300 hours so far.  I’m sticking with just the one though…

Edited August 9, 2023 by Ragsf15e

[A64Pilot]

21 hours ago, ArtVandelay said:

I just have to wonder how the electronics of the Surefly will stand up to heat and vibration over many years.

Really should if they are quality components last almost indefinitely, everything is electronic now, every chain saw, weed eater, lawnmower etc and the electronics seem to be the most trouble free things.  IF they are quality components and for the price they should be.

I listed things that get hot and vibrate excessively and are cheap, but of course add automobiles, outboard motors etc. we are in my opinion decades beyond when we should have gone electronic. Magnetos work, but so does a stick to beat carpets, I prefer a vacuum and believe it or not but Mags are older than vacuum cleaners.

Variable timing I’m not so sold on. I agree it certainly can make the engine operate more efficiently, but there are other considerations like the prop for example, when Hartzell or other manufacturers did the vibe survey it was done at the original engine timing spec and changing / varying timing can certainly change the vibration profile. It’s been years ago but I’ve spoken with Hartzell Engineers on this topic, I never had thought about it myself, but they indicated on some engine prop combinations it was a real issue. Plus some of our engines have swinging crankshaft counterweights, is it possible that variable timing could set up harmonics that could way down the road lead to fatigue and cracking crankshafts? I have no idea, but am sure no real testing has been done, analysis I hope so, but testing I don’t believe. It certainly could be a non issue.

We can’t necessarily apply automotive “truths” to our aircraft engines, sometimes yes, but not always.

Don’t fall into the trap of well it’s STC’d so the FAA has tested everything and found no problems, because that’s not how STC’s work. Or that x is a large technologically advanced corporation so no problem. I would have bet Lunch that Mobil-1’s Aviation oil would have been the best thing going, and I would have been wrong.

Mag’s aren’t the best, but they are well known, tried and true if you will, kind of like the carpet stick.

I would be hard pressed to buy new Mags though, I hope for me that’s years down the road. I have a (D) model engine