IRAN Right Magneto or Install SureFly?

[steve_falconer]

Initially I thought SureFly was a no brainer, but it looks like there were more troubles than I’d expect. For those who have given it a try, what has been your experience and what would you recommend doing it? Is Sureflybthe better approach? Would you IRAN the right and go EIS for one (or both) in a year or two when the left mag is ready?

My situation is my Right Mag is ready for overhaul and I could IRAN for $400-500 plus 2 hours labor to remove/install. About $750. I’m in a 2003 with IO-360 and CS prop.

Thanks for updates on your perspective on what’s changed.

[MarkA]

There were some problems with version 1 of the SIM4N dealing with voltage spikes that occur in DA40 and a number of other planes. This issue was addressed in version 2 of the SIM4N which started shipping around August of 2021.

I replaced the right mag in my DA40 XLS a year ago at the last annual and have been really happy with the results. I left the SlickStart module and left Slick mag in place unchanged and enabled variable timing on the Surefly. With this configuration, all 8 spark plugs fire when starting the engine (with the standard SlickStart configuration only 4 plugs actually fire) which makes hot starts a non-issue.

A copy of some background info and the instructions I gave to my mechanic to install the Surefly in my XLS is attached.

[steve_falconer]

There were some problems with version 1 of the SIM4N dealing with voltage spikes that occur in DA40 and a number of other planes. This issue was addressed in version 2 of the SIM4N which started shipping around August of 2021.

I replaced the right mag in my DA40 XLS a year ago at the last annual and have been really happy with the results. I left the SlickStart module and left Slick mag in place unchanged and enabled variable timing on the Surefly. With this configuration, all 8 spark plugs fire when starting the engine (with the standard SlickStart configuration only 4 plugs actually fire) which makes hot starts a non-issue.

A copy of some background info and the instructions I gave to my mechanic to install the Surefly in my XLS is attached.

Thank you so much Mark for the great guidance! It makes me feel confident that it’s a solid choice, and your instructions give me confidenCE It’ll go more smoothly. Do you see any practical difference in overall fuel consumption or changes in performance? Do you have an estimate for the number of hours or cost for the install?

Take care,
Steve

[TomO]

I installed an early version of the SureFly in Nov. 2019 for the left mag, disconnecting the SlickStart. I did not utilize the timing advance feature.

The starts are easy and the SureFly has performed as advertised.

I was fortunate in having none of the problems mentioned in the earlier threads.

I would install it again and wish I could do both mags.

[Chris B]

A copy of some background info and the instructions I gave to my mechanic to install the Surefly in my XLS is attached.

Mark -

I've been considering making this change to the right Slick magneto and your documentation is clear and thorough.
*Great* job. Thank you!

Your experience confirms that keeping the SlickStart (renamed "SureSTART" by Champion) and migrating the tachometer sensor is straightforward.

What CHT changes have you seen?

Any chance of posting some before/after (or with/without advance) flight data from climbs to ~10k?

Chris

[MarkA]

Unfortunately, I don’t have much “before and after” data on CHT or fuel efficiency change yet.

I was chasing a fuel flow imbalance issue for most of the long cross-country flights done since the Surefly was installed. Based on analyzing the flight logs, the fuel flow balance issue started about 6-months before the Surefly was installed so it was not related to the Surefly. Ultimately it turned out to be a failed fuel flow divider - the two pilot side cylinders were getting substantially more fuel than the passenger side cylinders making it difficult to run lean of peak. See the following thread for details: viewtopic.php?t=8598.

I’ve only done a couple long cross country flights with the Surefly since the flow divider was replaced. Subjectively, I can now lean more aggressively before any roughness starts and it seems to be using less fuel for the same performance in cruise. I’ve read in a couple of places the variable timing should result in a 4 – 6 percent reduction in fuel burn for the same performance at altitude in cruise. I should have some better data after the cross country flights I have planned for this summer.

[Rich]

Mark's writeup is great. My simplified history is I installed the original SF in Jan 2020 with advance enabled, replacing the left mag. The stumbling problem showed up immediately. Various things were tried to address the problem. It would come and go. Then SF realized there was a problem with 28V aircraft and supplied a fix in the form of a large capacitor and voltage downconverter on the input power feed circuit. This took care of the problem. We wrangled a version 2 replacement from SF and swapped them out in Sep 2021, removing the corrective devices. It's been working ever since. Even though I replaced the left mag, removing the SlickStart, starting, hot or cold is no problem.

The reason we chose the left mag to replace was simply it is much easier to get at for removal and reinstall and the ignition switch jumper removal and moving the tach sensor were not required. Nevertheless, sometime soon I will probably move the SF to the right position. This would thereby gain the theoretical advantage of both ignition gizmos participating in starting. Why do this? Welllll... It so happens for unrelated reasons I've wound up with a zero-hours-since IRAN left mag and still have the SlickStart which is easily reinstalled. And my right mag is not long to needing its IRAN. Since we would have to go through the R&R of that right mag anyway, we could just pull it, go through the couple extra steps for right mag, install the "0 hrs SIRAN" mag in the left position + SlickStart and voila! The IRAN hours get reset. The one extra thing we'll need to do is get a new piece of MAP tubing, as the one installed likely won't reach the right side.

Experience with this installation is generally higher CHTs and lower EGTs in some circumstances. This only becomes something to deal with in the presence of higher OATs. Keep in mind that at WOT below something like 5-6 thousand feet the unit doesn't advance spark at all. A note on higher CHTs. This is a known consequence of all spark-advance technologies. Diamond used to provide LASAR ignition (which advances the spark in both mags) back in the day, but CHTs were problematic. And even with only the traditional mags, a recommended technique to deal with problem CHTs is to retime the mags to fire later - changing from 25 deg BTDC to 20 deg. There is a Lycoming bulletin on this.

Speaking of Lycoming, the company markets an electronic ignition device which is a custom version of the SureFly that does not have a spark-advance option.

[MarkA]

I did find two flight logs with pretty much the same conditions before and after the Surefly was installed. The fuel imbalance issue I mentioned earlier also did not exist on either of these flights.

Both flights were done at 13,000 ft, ISA-10, wide open throttle, lean of peak to maintain CHTs below 380. It’s probably within the margin of error, but for this one example data point the Surefly resulted in about a 3 percent reduction in fuel consumption for basically the same performance.

As they say, “Your mileage may vary”

[AirHog]

Keep in mind that at WOT below something like 5-6 thousand feet the unit doesn't advance spark at all.

Can you elaborate on this Rich? Is it advancing at higher altitudes regardless of power setting?
What about lower power settings like 22-24" at lower altitudes like 2,500' to 3,500' ?

Thanks,
-
Bruce

[MarkA]

The SIM4N spark advance is based on two things, manifold pressure and RPM. The spark advance only starts when the manifold pressure drops below 24". The spark advance will also only start if the RPMs are above 400.

So if you are running WOT, as Rick indicated the spark advance will not start until you are at 5-6 thousand feet when the MAP drops below 24". However, if you throttle back to below 24" at any altitude (and you are running at or above 400 RPM) the spark will advance.

For example, if I'm just flying around in the practice area and not trying to get anywhere in particular, I sometimes cruise around at 21" of MAP, 2200 RPM and lean to about 6.2 gph.