SureFly Electronic Ignition Module

[jliltd]

I opted to try a new SureFly SIM4N non-impulse ignition module in place of the right Slick magneto in my 200hp A-1B. It was time for a 500 hour inspection on the mags and I have been having starting problems in the injected angle valve engine as of late (both hot and cold). And I have a lot of experience hot starting Bendix RSA equipped Lycomings.

I chose the non-impulse model SIM4N because I figured that it ,combined with the traditional impulse coupled left magneto during start, would give me all the starting ignition fire available. Since I was replacing the right magneto I accessed the ignition switch and removed the jumper that traditionally grounds the right mag when the key is in the start position. Leaving this jumper in place would mean the SIM (SureFly Ignition Module) would not fire for start.

The SureFly installation requires the new SIM be directly hot wired to the battery with 10 amp circuit protection. This bypasses the master switch and ship's electrical bus so that the SIM always has power, similar to a magneto still working no matter any electrical bus condition.

Since the Husky has the battery and both solenoids under the rear baggage compartment I had to install the new breaker aft in that location. I routed the new ignition wire from the breaker forward through the firewall to the SIM per the instructions.

I opted to set up the SIM with fixed timing matching the engine dataplate; 20 degrees BTDC. There is no practical or performance reason to attach the manifold pressure line to the SIM to engage it's advance timing curve function. It is much more conservative, especially on the angle valve engine, to stick to fixed timing. The RV and Glasair guys all rant and rave about such things as timing advance curves but they are in a different mission profile and altitude regime than a bush plane like a Husky.

After removing the mag gear from the Slick I installed it on the new SIM. In order to time the magneto I attached a 9V transistor battery to the SIM timing terminal with a pair of alligator test leads and turned the mag gear to just at the point where the led light on the unit went out. With the engine positioned with #1 cylinder on TDC we stabbed the mag and then verified the timing LED would go out at top dead center cylinder.

The aircraft now starts in half a blade cold and one blade hot. And it has been hot, baby. 105 degrees F on the ramp today when testing. I have 4 flights in on the system and am very happy. This was all done for ease of starting and smooth cruising. Not for any increase in economy or the like. I will leave Thursday for Oshkosh and my trip will be a perfect opportunity to really shake down the new ignition.

Jim

 

[joemcd]

I look forward to a full report. Keep us posted.

Thanks,
Joe

 

[Ak Kurt]

Jim,

Thanks for taking the time for the report! Please keep us posted on your findings.

Kurt

 

[Flying Dave]

I’ll echo what has already been said. Plus, have a safe trip! Lol

 

[FW Dave]

Staying tuned.. excellent.. see you at OSH.

 

[jliltd]

Over the Texas panhandle at 7500. This SureFly starts an injected Lycoming hot or cold. Like a new automobile.

 

[jliltd]

Back from Oshkosh. The Surefly worked great. Starts much better now and runs smooth. For the same price as a Slick magneto.

Jim

 

[Snowbirdxx]

How is the surefly performing if a battery fails? Does it need battery power for normal ops or just to start?

 

[jliltd]

It is totally dependent on electricity. That's why the STC requires keeping one original magneto of the owner's choice. I chose to keep the L impulse mag and replaced the R mag with a SureFly SIM4N. My logic being if the battery is dead it is easier to handprop on the L Slick impulse mag. And during normal operations I now have two ignitions firing on start, one of which is the higher energy SureFly firing at TDC for start augmented by the legacy impulse coupled mag. I removed the jumper from the mag switch that used to ground the R mag on start to enable the dual ignition start.

I have an EI electronic tach (part of the CGR 30P engine monitor) so I had to replace the original EI isolator from the R plead with a 1/4 Watt 18 KOhm resistor. Without the resistor the electronic tach can't read RPM from the SureFly pulse so mag check shows zero and the mag failure annuciator stays lit. The engine runs great but swapping the resistor returns normal rpm readings to the electronic tach. This is not in the installation instructions but can be found in the product FAQs on the web site.

I am very happy so far with about 25 hours on the setup.

Jim

 

[FW Dave]

Jim, can you show pics on your change to the isolator on EI, tach P lead?

 

[FW Dave]

How is the surefly performing if a battery fails? Does it need battery power for normal ops or just to start?

The Sure fly guys said that it could operate with reduced voltage from the battery down around 5-6 volts even though the spec says 8 volts as the power fades from the battery. so pretty much it would have to be dead.. Im carrying one of those small start assists batteries with me that will turn the motor over a few times.. its starts my car too.

The way I understand the future Lycomings dual setup, that is being vetted, there is a backup battery and power lead that is isolated. The battery pack has its own regulator and simply accepts 12v from the main relay to recharge, and remains in stand by, much like an IBBS setup for avionics.

 

[Snowbirdxx]

Well in this case the LiFePo lightweight batteries with build in BMS are a nogo with the electronic ignition.

 

[tbienz]

The fact that an aircraft engine can continue operating in the complete absence of electrical battery power by generating it's own electricity has always been something that I've found fascinating from an engineering perspective. I'd hate to give that up. The single electronic mag with two firing on start sounds intriguing though...seems like it might be the best of both worlds: better start, better cruise, and still able to hand-prop.

 

[Gust Kalatzes]

Why would one not have the impulse coupling on both units...Surefly and one current mag? Is it because the receiving RH gear in the case not correct to receive an impulse coupled mag or some other reason?

 

[Snowbirdxx]

I am sure that sooner or later the electric mags will have build in generators, making the electricity they need to be independent. E- mags, if I recall right are already doing this.

 

[Proteus]

Thanks for the detailed write up. Very interesting. Have Lycoming not also announced recently about them producing an electronic magneto ? I wonder how that will compare too

 

[joemcd]

The Lycoming e-mag is in partnership with Surefly. It looks identical to the Surefly. I anticipate they will be exactly the same.

 

[jliltd]

Why would one not have the impulse coupling on both units...Surefly and one current mag? Is it because the receiving RH gear in the case not correct to receive an impulse coupled mag or some other reason?

Gust,

Good thinking. But don't let your thoughts get caught up in the traditional impulse coupler spring.

There is no such thing as in "impulse coupler" SureFly. It doesn't need one. The SureFly SIM electronically sets the timing to TDC at start. So there is no longer a need for an impulse coupler of any kind. The SureFly SIM N (non-impulse replacement ) or P (impulse replacement) units are identical internally and the only difference is the portion of the housing that stabs into the accessory case and the length of the shaft. It is only geometrical differences between the SureFly N and P models and SureFly offers these two configurations so that the aircraft owner can re-use the existing drive gears which are different depending on what type of legacy mangeto (impulse or non-impulse) they came on. SureFly's efforts keeps costs down by not requiring the purchase of any Lycoming parts to do the conversion.

This is as opposed to the likes of E-Mag which only has one unit configuration whether replacing an original impulse of non-impulse mag, requiring the owner to purchase a new non-impulse gear when replacing an original impulse mag with a P-Mag.

So replacing the non-impulse magneto with the N model of the SureFly and ensuring the start switch doesn't ground any plead at start yields the same result you are wondering about in your question. That's one of the nice things about the SureFly. It works at start better than an impulse magneto without the associated mechanical spring based impulse coupler as a wear and tear and complexity item. So what you described is what I did by replacing my non-impulse mag so I have both legacy impulse magneto and modern SIM ignitions firing at start while backing up each in the case of battery failure or mechanical impulse coupler failure.

Jim

 

[Gust Kalatzes]

Thanks for the explanation Jim.

 

[tbienz]

So Jim...sorry that I'm slow on the uptake, but I need to understand what you wrote as I'm considering getting one of these instead of overhauling both of my Slicks. I think the answer to both of the following is YES, but I want to make sure.
Lets say you have your current arrangement, you are out in the sticks and your battery dies...you can still hand-prop because the mechanical impulse mag is still connected. Correct?
How about if your battery is fine, but your impulse mag dies? Can you still start the plane with a non-impulse SureFly N? In other words, if you don't have your ignition system set up to ground the SureFly N during start, will it fire the appropriate time at TDC to allow for start even though it's an N and the mechanical impulse mag is dead? Thanks.