Surefly SIM6L 6 Cylinder Lycoming Magneto Replacement

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Part# 08-17076
MFR Model# SIM6L


Now approved for many turbocharged twins and most 4- and 6-cylinder Continental & Lycoming powered aircraft.

Note: Surefly strongly recommends the customer purchase a NEW slick-style harness and fresh spark plug set with every SureFly SIM.

Replaces 6-cylinder magnetos on Lycoming engines. 5.2 lbs.

SureFly is an FAA certified electronic (solid state) magneto replacement. The SureFly Ignition Module replaces one magneto - generally the left or impulse-coupled/starting magneto on most aircraft. 4 and 6-Cylinder models are available for Lycoming and Continental engines.

Replacing just one magneto eliminates magneto maintenance and cuts associated costs in half! Zero maintenance. Zero rebuilds. Zero overhauls. Most fixed-wing single engine aircraft can enable SureFly's advanced timing feature for improved cruise flight efficiency. Many other aircraft will be able to use the advanced timing feature as the FAA extends SureFly's Airframe STC AML.
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For SureFly customers, 500 hours is simply not good enough. SureFly Ignition Modules provide operators a 2,400 hour operating service time. No inspections, no rebuilds, no overhauls. That prevents scheduling headaches and down time. That saves money. Period.

SureFly Ignition Modules have no mechanical parts that wear and all solid-state electronics. There's no need to disassemble a SIM like a magneto every 500 hours - which eliminates the chance of introducing a maintenance related failure.

SureFly Ignition Modules deliver a more consistent spark energy with higher accuracy than traditional magnetos. Variable timing advance provides SureFly customers real fuel savings. Low power consumption and light weight (up to 2 lbs. lighter than a Bendix magneto) make SureFly Ignition Modules light on fuel and light on the wallet too.

Better Starts
SureFly perfectly controls timing at TDC below 400 rpm which combined with longer spark dwell and the option to use wider gapped spark plugs, makes starting a breeze, greatly minimizing wear and tear on high performance starters and electrical systems.

SureFly Ignition Modules are hand built in Granbury, Texas almost entirely from components manufactured in Texas and Michigan. Designed, engineered, created and supported by the same team that brought you Sky-Tec starters and Plane-Power alternators, our approach to SureFly shares the same commitment, experience and passion for creating and bringing sensible, affordable solutions to the piston engine aviation market.

With the low cost of the units, combined with SureFly's potential fuel savings and low maintenance/replacement costs, there is simply no better value in magneto replacements for Lycoming and Continental engines.


  • Aviation spark plugs – gapped .016 to .036
  • Slick style harness – Shielded aviation harness
  • Input voltage 6-30 volts
  • Avg. Current @2700 500mA
  • Retards spark to TDC for starts
  • Up to 38 degrees Ignition advance – RPM & MP based
  • Hall Effect sensors provide velocity and position input
  • Manifold pressure sensor range – 6-74 inHg
  • Operational temp range -35 to 250 F
  • Minimum MTBF 2000 hrs
  • No interval inspections
  • RPM range 0-3500
  • Voltage to bridge .036 spark plug gap
  • Minimum 35mJ spark energy
  • 50mJ nominal energy


    Intelligent Timing Advance
  • For non-turbocharged engines, SureFly controls spark advance up to 38º before TDC as determined by manifold pressure and RPM (engine power setting). Each engine's base timing advance is read off the data plate and set into the SureFly Ignition Module or, "SIM" at installation. The timing advance schedule is hard set at the factory, when the SIM is manufactured, to provide the highest possible combustion efficiency.
    No Mechanical Points
  • Not only are points and condensers a point of failure in magneto ignitions, so are rotors and caps as they carbon track and provide alternate paths to ground as resistance builds in the system. That's why SureFly utilizes none of these antiquated technologies. SureFly components are all solid state and industrial-grade electronics.

    The result is zero maintenance, zero overhauls, no rebuilds, and no maintenance costs whatsoever! Nothing to wear. Nothing to maintain. Run it to 2,400 hours of SIM operation.


View the latest eligibility chart at Application Guide

If any of the following items apply to your installation, please call SureFly at 817-373-5161 before proceeding with the purchase or installation of a SureFly Ignition Module:
  1. Your aircraft tachometer is one of the following:
    1. Horizon,
    2. Electronics International,
    3. EFIS or Engine Monitor that requires magneto P lead inputs,
    4. EFIS or Engine Monitor that requires a 0-5 volt square wave input,
  2. Your aircraft has more than one engine,
  3. Your aircraft has an existing electronic ignition,
  4. Your aircraft has one of the following STC’s:
    1. Western Skyways Turbo STC,
    2. Auto Fuel STC.
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I have installed several of these on customers planes. Easy straight forward installation. Be sure you have a good or new ignition harness.

Executive F Verified Purchase


September 29, 2023

What an awesome product so far. Minimum rpm drop during mag check. Hot start issue is a thing of the past.

Eric T Verified Purchase


August 16, 2023

Very easy to install and works great.

Jeff N Verified Purchase


August 5, 2022

Easy to install, excellent customer support from surefly.

Matthew J
November 16, 2020

PRO: SureFly Magneto bought to replace Slick 6393 & SureStart Booster was easy change for RV10 builder. CON: After installation I find out there is 100 mil second dead spot designed into unit that when doing magneto check will cause backfire due to ACS 510-2 starter switch which most builders use. There is a fix according to SureFly GM, but not for some time into future. Also mag not compatible with GRT EIS6000 engine details for RPM display w/o using UMA MAG sensor in right Magneto. I try to get more hi-tech, yet retreat to decades ago to get RPMs 🤔

Norm R
May 22, 2020

Engine on my Cherokee six preforms better with ignition.

Jeffrey M
October 29, 2019

I like the unit but was unhappy to find out that there could be an issue with 24v systems. On an over voltage the unit recycles. This should have been told to be at time of sale by spruce and shipped me the newest rev. Now I have to install a power conditioner and a large capacitor. The newest rev. includes the fix but Spruce has old inventory they need to sell. I would reach out to surefly directly next time. Yes it costs more to install the extra items. I was told it may not happen but if it does you lose the unit for several seconds. To be fair it is a nice product but I do not want to take a chance of an unexpected ignition recycle. Ask questions.

Steven B Verified Purchase


May 14, 2022

Only complaint is that the installation instructions left something to be desired. The A&P had trouble, I had trouble, we talked to tech support twice during the installation. Looking back after completing one I could knock this installation out in an hour or two tops, it could be that easy. The way it was it took about 6 hours. A detailed video explaining some of the nuances would have been very beneficial. We tried YouTube but nothing very detailed. Once completed it runs flawless (first try) and I am glad I installed it. PS, it could have come with a nipple for the manifold pressure, be sure to purchase a 1/8 NPT to 1/8 hose barb.

Brian T
January 20, 2022


Please note,'s personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.

Q: Is the 8130 form included with the Surefly SIM6L free of charge?

These units come with copies of the airframe STC and engine STC in the box. If an export 8130-3 form is required, it will need to be requested at the time of order for an additional charge of $50 USD.

Q: Does this unit replace the impulse coupling/left magneto and is the price the same for a non certified/experimental unit?

The SureFly Ignition Module replaces one magneto - generally the left or impulse-coupled/starting magneto on most aircraft. They do not have an experimental option for Lycoming 6 cylinder engines, this can be used on both certified and experimental.

Q: Can both mags be replaced with SureFly units?

Not for certified aircraft.

Q: Can the Surefly SIM6L replace the non impulse Magneto?

Yes, it can replace either style of magneto.

Q: At this time is it possible to get a 337 form and 8130-3 Form with the SIM6L

We have a sample 337 on the website and we can provide an 8130-3 for a $50 fee.

Q: Does the SIM6L include the required installation hardware?

The following ships in the box:
1. SureFly Ignition Module (SIM)
2. Power wire harness (84" long 14ga. wire with inline fuse holder, 10A fuse & ring terminals)
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