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  • What's in the box?
    1. SureFly Ignition Module (SIM) 2. Power wire harness (84" long 14ga. wire with inline fuse holder, 10A fuse & ring terminals) If your battery is located in the tail of your aircraft, you will need to purchase a longer power wire. 3. Manifold pressure hose (36" long 1/8"ID x 1/4"OD high temp. rubber hose) 4. Engine STC paperwork 5. Airframe STC paperwork
  • What does it weigh?
    SIM4P - 4.4 lbs. SIM4N - 4.0 lbs. SIM6C - 5.0 lbs. SIM6L - 5.2 lbs.
  • Will the SIM help my engine start?
    Absolutely! Compared to a magneto, the SIM provides a more accurately retarded spark and a more consistent, higher energy spark at low engine RPM. Hot-starts are greatly aided by the installation of a SIM, but keep in mind SureFly can’t remedy fuel system shortcomings!
  • Should I replace the impulse or non-impulse magneto with a SIM?
    SureFly recommends replacing the impulse coupled magneto. This is to reduce the possibility of impulse coupler mechanical failure and also to help the engine start better.
  • Can I replace both magnetos with SIM’s?
    Yes! FAA STC was issued in July, 2023. See the details in the STC here.
  • Does SureFly have a SIM replacement for single-drive dual magnetos?
    Unfortunately not. We expect to work on that after we have certification to replace both magnetos on an engine.
  • Can I use automotive spark plugs with a SIM?
    The SIM is compatible with all automotive and aviation spark plugs. SureFly’s FAA STC’s do not grant permission to use automotive spark plugs in FAA certified engines. You may only use spark plugs FAA-approved for your application.
  • How is the SIM turned on and off?
    The SIM is turned on and off with the existing ignition switch through the p-lead wire connected to the p-lead terminal of the SIM.
  • What are the advantages of a SIM configured for fixed timing over a magneto?
    The SIM is a solid-state ignition module with the benefit of improved reliability and zero maintenance (no rebuilds & no overhauls) over the lifetime of the SIM. Another benefit is improved starting.
  • What is the service life of a SIM?
    Return the SIM to SureFly for evaluation after 2400 hours of SIM operation.
  • Does the SIM output a tachometer signal?
    The SIM outputs a 60Vdc spike with a 10Vdc offset on the p-lead (2 pulses per rev for 4 cylinder models & 3 pulses per rev for 6 cylinder models).
  • Will the SIM work with Electronics International brand tachometer?
    Electronics International's R-1 RPM Instrument - The R-1-4SM and R-1-6SM units are setup to interface with the SureFly system on one channel and a standard mag on the other. These units do not require the SureFly Tach2 Tachometer Signal Converter. Any R-1-xx instrument configured to monitor a standard mag will also work with a SureFly system by placing Electronics International's VI-2uf Voltage Interface module in series with the R-1-xx channel and the SureFly P-Lead. Electronics International's MVP-50 and CGR-33 Instruments - These instruments use an EDC-33 Engine Data Converter. Place an Electronics International's VI-2uf Voltage Interface module in series with the EDC-33 RPM channel and the SureFly P-Lead. An alternate method is to use the The SureFly Tach2 Tachometer Signal Converter. Connect the Tach2 output to an EDC-33 RPM channel (no isolators required). Only these configurations should be used. Note: The Tach2 outputs 1 pulse/rev for a 4-cylinder engine and 1.5 pulses/rev for a 6-cylinder engine (1/2 times the ignition events). For this reason the LSB setting in the MVP or CGR for the SureFly RPM channel must be reduced by one count.
  • Will the SIM work with Horizon or B&D Industries brand tachometer?
    For Horizon installations, you will need to install a TACH2 signal converter to make a SIM compatible with a Horizon tachometer. For B&D installations, Possibly. Customers have reported mixed results getting B&D tachometers to work with SIMs, however successful installations required a SureFly TACH2. We tested B&D P/N 0513-019 with our TACH2 and we were unsuccessful in getting it to work. UMA tach display P/N 19-51A-10C is 2 1/4" and can be used with the SureFly TACH2, 0-5V output terminal. This is a custom tachometer for 6 cylinder applications. If you decide to go this route, you may consider using a UMA tach drive or magneto pickup for your tachometer signal instead of P-leads and the TACH2. Contact UMA for your application.
  • Will the SIM work with the tachometers in Garmin and other EFIS and Engine Monitors?
    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.
  • Why is variable timing not available for a turbocharged, turbo-normalized or supercharged engine?"
    Upon loss of manifold pressure input, a SIM configured for variable timing will calculate advance based upon pressure altitude. In this unlikely scenario, variable timing may result in engine detonation margins too narrow to safely operate a turbocharged aircraft at high altitudes.
  • Why is variable timing not available for engines that burn less than 100LL fuel?
    We have a limitation on our STC because we have only tested the variable timing schedule with 100LL fuel.
  • What spark energy and voltage does a SureFly output?
    We are often asked about how "hot" our spark is. What most people actually mean when they use that term is - "How many volts will your ignition output?" The truth is, voltage is only half of the equation. The total output energy is measured in millijoules(mJ), and the voltage at the spark plug varies in proportion to the gap of the spark plug. The SIM produces 45mJ of energy at the spark plug (the same as a Slick Mag at 2700 RPM) and 60mJ of energy during start sequence.
  • Where do I connect the SIM to aircraft electrical power?
    SureFly’s STC requires you to connect the SIM directly to the aircraft’s primary battery. You may connect the SIM power wire directly to the battery’s positive terminal or to the battery input terminal of the master solenoid. A power wire harness with terminals is provided with the SIM.
  • Can I protect the power wire with a breaker instead of a fuse?
    Yes, but SureFly advises you to use the provided inline 10A fuse and holder to protect the power wire.
  • Where is the best place to connect the SIM to manifold pressure?
    A 36” long 1/8”ID x 1/4”OD hose is provided with the SIM to connect manifold pressure. The installing mechanic is required to provide appropriate fittings based on the choices below: Option (a): Tap into existing MAP gauge plumbing with a T-fitting (recommended). Option (b): Hose barb in threaded port on cylinder head. Option (c): Hose barb in threaded port along intake track.
  • What is the recommended spark plug gap for the SIM?
    SureFly recommends the upper end of manufacturer's recommendations for plug gap. Best performance is realized with a gap of 0.022" - 0.035".
  • What fittings do I need to connect our 1/8” tube to an AN8 hose
    Here are a couple fittings that have worked well for other customers: TR-08-02-A -8AN Male to -8AN Female w/ 1/8” NPT port $15.90 MSC Part# 48755003 1/8 NPTF Thread Hose Barb x Male NPT Connector $1.76 Mfr Part# P-201A-2A
  • How do I install a second SIM in conjunction with a TCW 3AH Battery Backup System?
    This information is contained in SureFly document document SF2001, Airframe Installation Instructions, and TCW instruction manuals.
  • What RPM drop should I expect during a Mag check at run up?
    You should expect a normal 50-100 RPM drop during a mag check. If the rpm drop is greater on the SureFly, you should verify the remaining magneto is timed correctly - it is not uncommon for the remaining magneto timing to have changed a few degrees from its initial installation.
  • Why does the engine stumble during mag check?
    On some aircraft there is a slight engine stumble when doing a mag check. We have discovered that some mag switches actually ground both ignition systems in the transition between Left and Right positions. The SureFly Ignition Module requires a few milliseconds to power up after being tuned on. This only occurs on a small percentage of aircraft. If you are one of the lucky ones, stay tuned as we are working on a solution. We have found that turning the ignition switch slowly between positions masks this issue on most aircraft. Another remedy to mask the issue is to reduced power to idle before returning to "Both". Sequence as follows - Both, Left, Right, reduce power to idle and move back to Both. Please make sure your ACS aircraft ignition switch is in compliance with AD 93-05-06.
  • Can I perform a high voltage lead test?
    Yes, but do not perform a high tension lead test with the harness connected to a SureFly. Remove the harness cap from the SIM before testing the leads.
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