Surefly electronic ignition

[Skykingbob]

Originally Posted by Carl Froehlich

The short answer is no.

There are many practical options to support dual ship power dependent ignitions, this is not one of them.

Carl

Hey Carl....would you care to expound on the rational for your statement? Electrical components care not where the juice comes from and I know you have background in electrical engineering (I believe) and would love to learn the "why" of your statement above.

Thanks.......Bob

[DanH]

Let's not launch into power supply in this thread. Important subject, but not specific to the Surefly. I'm just sayin'...

[jliltd]

I will be mounting a SureFly on my angle-valve Aviat Husky today. Going with fixed timing of 24 degrees (data plate says 25). With fixed timing no manifold pressure line hookup is required so that port on the SureFly is plugged. My SureFly is replacing the non-impulse Slick on the right side so I will remove the grounding jumper from the ignition switch to allow firing both the magneto and SureFly on start.

Jim

[Carl Froehlich]

Originally Posted by Skykingbob

Hey Carl....would you care to expound on the rational for your statement? Electrical components care not where the juice comes from and I know you have background in electrical engineering (I believe) and would love to learn the "why" of your statement above.

Thanks.......Bob

I don?t recommend running any alternator without a battery. Happy do provide some detail if you PM me your email address.

Sorry Dan for the thread drift - just answering Oly?s question.
Carl

[pecanflyboy]

I've now replaced both of my Slick Mags with Surefly SIM's on my RV-6, and I love it. I have a Lycon, high compression IO-360. Engine starts MUCH easier, hot or cold. Smoother. I can easily run LOP. It's just happier overall.

I'm working on a small battery backup in the unlikely event that the alternator and the battery suddenly die at the same time. I say unlikely because the SIM's will supply ignition down to 8.5V. If I were to miss my alternator failure warnings, my avionics would shut down well before the SIM. The SIM only uses 600mA at 2700 RPM, so I should have plenty of time to find a place to land. A small 12V backup battery would give me a lot of time at only 600mA.

I've read where users are adjusting their base timing away from the data plate timing on the engine. I would highly discourage this practice as Surefly, in conjunction with Lycoming, has exhaustively developed a proprietary ignition curve which depends on the user setting the base timing at the engine spec. Anything different is at your own risk. Note that the curve that has been referenced on this thread is dated 2016, version 1.0.

If you want to experiment with your ignition curves, I'd suggest you go with one of the alternative EAB ignition systems. Good people, good products. If you want a simple magneto replacement that gives you reliable ignition with advance timing, consider the Surefly. Lycoming did!

[norcal64d]

Gents, I have been following this thread for awhile and I thought I would throw my experience in here. I am flying a Maule with an O-360 and I have about 40 hours on the SIM4N and Slick combination. I was using the timing advance and what I noticed was my takeoff power and climb capability seemed to be very diminished on high DA days here in Colorado as compared to how it performed with two Slicks. It was very noticeable once DA got above about 8500ft, while around 6000ft DA the plane performed significantly better. I called Surefly and given my conditions on a 8500ft DA, at 2700RPM and 21" of MP the Surefly was running at the full 38 degrees of advance. Their rep suggested that it was perhaps not correctly timed, so I verified the timing and ended up switching it back to 24 degrees fixed timing. The plane appears to have the power back, shorter takeoff rolls and the climb rate was back as well. I don't have a ton of data other than just rate of climb, but given the same conditions, weight, etc, advanced timing gave me a 400-500fpm climb out vrs 700fpm at 8800-9000ft DA.

The Surefly reps say that this is all backwards and it should have more power given that 38 advance and they suggested that maybe I need to open up my spark plug gaps since they are all brand new and came gapped to the .016" give or take that tempest plugs come with.

[rv6ejguy]

Originally Posted by norcal64d

The Surefly reps say that this is all backwards and it should have more power given that 38 advance and they suggested that maybe I need to open up my spark plug gaps since they are all brand new and came gapped to the .016" give or take that tempest plugs come with.

Perhaps I'm not understanding here but I hope Surefly isn't saying that best power is made at 38 BTDC?

This flies in the face of plenty of dyno and flight data saying that isn't so. 38 will give you way less power, high CHTs and detonation almost for sure.

[lr172]

Originally Posted by norcal64d

Gents, I have been following this thread for awhile and I thought I would throw my experience in here. I am flying a Maule with an O-360 and I have about 40 hours on the SIM4N and Slick combination. I was using the timing advance and what I noticed was my takeoff power and climb capability seemed to be very diminished on high DA days here in Colorado as compared to how it performed with two Slicks. It was very noticeable once DA got above about 8500ft, while around 6000ft DA the plane performed significantly better. I called Surefly and given my conditions on a 8500ft DA, at 2700RPM and 21" of MP the Surefly was running at the full 38 degrees of advance. Their rep suggested that it was perhaps not correctly timed, so I verified the timing and ended up switching it back to 24 degrees fixed timing. The plane appears to have the power back, shorter takeoff rolls and the climb rate was back as well. I don't have a ton of data other than just rate of climb, but given the same conditions, weight, etc, advanced timing gave me a 400-500fpm climb out vrs 700fpm at 8800-9000ft DA.

The Surefly reps say that this is all backwards and it should have more power given that 38 advance and they suggested that maybe I need to open up my spark plug gaps since they are all brand new and came gapped to the .016" give or take that tempest plugs come with.

Herein lies the problem with canned timing curves. 38* at 8500' when LOP with one traditional mag (25*) doesn't seem that high. I run just a few degrees less than that in LOP cruise, with one mag. However, at t/o power, full rich with two EI's, both at 38*, I am not surprised you are seeing a significant fall off in power. Even with one mag @ 25*, this is still way too much timing for best power / ROP operations.

Larry

[Toobuilder]

Agree with Ross and Larry, and will double down on the hope that the Surelfy rep didn't think 38 degrees at TO power is a good thing.

[jliltd]

On my SureFly I opted for fixed timing (25*) rather than hooking up the manifold vacuum line. I have an agle-valve IO-360 and everything I reasearched and found answers to on VAF led me to go with fixed timing. My objective with SureFly (and P-Mags for that matter) was easy starting and smooth running. On my P-Mags I would choose fixed timing if it were an option like SureFly. So I just use the least aggressive curve on the P-Mags.

And I have to say I am very pleased with both systems. In my Husky with the angle valve fuel injection the airplane starts super easy, hot or cold. That was transformational on that bird. I would recommend SureFly as a cure to injected hot starts without a lot of mixture and throttle fuss. The P-Mags came on my inected RV-8 and I am satisfied with the timing jumper connected. Then again I am super happy with my old Bendix mags on my RV-3. It starts and runs great and Bendix are solid mags compared to Slick. If they ever act up I would lean towards a EI solution.