Surefly SIM

[Steve Pierce]

I know experimental guys that run variable timing in the cockpit and go way beyond 4-5 degrees. Harry told me the FAA limited the advance on the Lazar system where there wasn't much advantage over fixed timing. They did start nice and run smooth at idle. I like the SureFly SIM for ease of maintenance. I get tired of Champion issuing service bulletins and having to work on mags because the things they changed didn't work out. I don't usually go high enough to see any savings in fuel burn. It also starts on the 3rd blade like clock work. Also from talking to the engineer at SureFlly I can run the gap wider and have less propensity to fouling a plug.

[Vagabondblues]

I know experimental guys that run variable timing in the cockpit and go way beyond 4-5 degrees. Harry told me the FAA limited the advance on the Lazar system where there wasn't much advantage over fixed timing. They did start nice and run smooth at idle. I like the SureFly SIM for ease of maintenance. I get tired of Champion issuing service bulletins and having to work on mags because the things they changed didn't work out. I don't usually go high enough to see any savings in fuel burn. It also starts on the 3rd blade like clock work. Also from talking to the engineer at SureFly I can run the gap wider and have less propensity to fouling a plug.

Yes.... the experimental electronic ignitions and Surefly are not limited by CHT control or a 3 dimension map. I have been cognizant in all my posts to avoid the closed loop 3D RPM/MAP/CHT mapping as we are talking about 2D mapping. I was not employed by Unison when the mapping was done at Lycon. According to Harry it was open loop 2 dimensional at first. That is only RPM and MAP (manifold absolute pressure). As I understand it Cessna and Piper objected to the open loop 2D function as the CHT varied by CHT probe location and baffling designs across the two manufactures TCDS mandates. i.e. Hottest cylinder in climb # 3? #4? where is it mandated to go? Did the TCDS argument grow and the FAA stepped in during certification? I don't know. I also don't understand how the FAA would mandate it on LASAR and then allow it unchecked on Surefly.

Back then I was a parts changer sent out to fix LASAR units all over the US. Being a problem solver I wanted information, data to see what was going on inside of the box. was it working? what was it advancing? Was it even working without any cockpit interface? Back then only the important people like Harry had laptops. About 97,98 Compaq made one of the first tablets with Microsoft windows. I tried and tried to get it to sync with the box. No assistance from Unison, so I took that as they didn't want me to see what it was doing. Most Customers had laptops and cables with DB9 connectors, so I used theirs. Experimental mostly... Vans RV's so no CHT control 3D map. I remember vividly flying from the spot the Orville and Wilbur first flew from. Which is pretty close to sea level as you can get and thinking 6 million dollars in development cost and this thing only advanced 1 degree. When does the 46 BTDC come in? at what manifold pressure? Again I was not employed when it was mapped.

Yep, for sure Surefly is a good "electronic" magneto. No points, Condenser, to control Egap. Yep... smoother.... starts easier. But without cockpit control, feedback indications what are the effects of advancing the timing? Higher CHT? Fuel economy? Gamblers will always tell you about their winnings and never about their losses.

For me, I see these guys in a new jeep going down the road. Lift kits, oversized tires, winches, spare fuel tanks and tire ramps on a rack. Driving down a paved road!!!! Do they need it? No! Did they want it? of course they did! That's what the marketing guys see in the electronic mags "gotta have it"

In my opinion... it has almost been more than 25 years since electronic ignition came out and the engineers at Lycoming and Continental knew what they were doing back then and made the best compromise.

Call me weird, but I like working on magnetos, challenging my brain, keeping my skills current. In this "set it and forget" it society what will happen to those skills?

[Subsonic]

Ok, I'm calling you weird. Don't invite what you don't want.

First, you confuse me when you say 1 or 2, or 4 or 5 degrees. Can you simply use ABSOLUTE numbers, please?

What you should have said is : the UNIDENTIFIED ELECTRONIC IGNITION that you were working with about 25 years ago had a 2D map and was only advancing the absolute lead 26 or 27 degrees at SL, or up to 29 to 30 degrees at higher altitudes and lower MAP's.

I think the pertinent information you were attempting to convey is the fact that the SureFly SIM also uses a 2D map. I get that.

Cool. Don't care. Not pertinent to the SureFly SIM. Have you seen their 2D map for total timing as a function of manifold absolute pressure? I have not. Do they publish that data? Have you compared SureFly's 2D map with the unidentified 2D map you worked with 25 years ago?

Third, I'd also appreciate it if you stick to the topic and stop talking about your whining to get a laptop 25 years ago and Jeeps with skyjacks, and keeping your brain working. We're all working on keeping our brains working. That's not the discussion here.

Bottom line: We are talking about the variable timing advance on a SureFly SIM and you are talking about something else. And, if you haven't noticed, Lycoming now sells their new engines with the SureFly SIM's installed.

[Vagabondblues]

I would not call it whining it’s more like bitterness or resentment

[Steve Pierce]

I would not call it whining it’s more like bitterness or resentment

That is how I feel every time I have to remove and disassemble a Champion/Slick magneto because Champion changed something, it didn't work and now we have to fix it at the customer's expence. Changing 8 things on the points at one time was crazy. Points would wear in less than 100 hrs and the engine wouldn't start because the timing was so far off. Was interesting to learn the Unison/Slick built every part for their mags in house including the screws. Champion buys them and outsources everything and all the problems started.

[Vagabondblues]

Ok, I'm calling you weird. And, if you haven't noticed, Lycoming now sells their new engines with the SureFly SIM's installed.

I have been to the Lycoming factory service school twice in my career as a A&P, IA, DME. Once as a tech rep for Unison/Slick. And the last time was because the FAA has now mandated the part 147 schools teach FADEC theory of operation. That is Full Authority Digital Engine Control. Since Lycoming has also added "Surefly" to their factory school, my college determined that I should go to revise our curriculum as mandated by the FAA.

Just so you are informed "All Certified" ignition products used by Lycoming are covered under the same service documents SL1443. Look it up! And to clarify further that approval is only for the engine. Lycoming says to contact the FAA for feild approval of the dual variable timing sureflys that are installed on their new engines. In other words, you can make new airplanes with the dual surefly and add a battery bus, cht data, but good luck getting approval in the aftermarket STC owner installed.

[Steve Pierce]

Cub Crafters has airplanes certified with the dual SIMs and backup battery and SureFly, on the FAAs request are STCs using two SIMs. I think it is a good thing. Less moving parts and redundancy. Call SureFly and talk to the tech. He is a good guy and I always learn something when I talk to him. I know most of those guys from the SkyTec starters and Plane Power alternators days. They are a 30 minute flight from me. Sharp folks and very helpful. Called Champion about a mag issue lately? Since Joe left it is a cluster.

[Steve Pierce]

Looks like they got the STC for dual SIMs. https://www.surefly.aero/