I have dual Surefly's on my RV6 powered by a Lycon IO360-EXP with 10:1 pistons. I'm in Granbury, and know the Surefly guys, very well. I don't speak for the comapany, however.
The Surefly was designed to be a magneto replacement for the certified market, that will last the TBO of the engine without maintenance or inspection. The ignition advance keeps the engine well within the detonation margins, similar to the magneto. You will not get advance until the MP gets below appoximately 25". So, WOT, low altitude, the unit will only provide base timing, just as the mag did.
MOGAS was not in the STC because it was not tested. The FAA cannot handle variations, and the fact that auto fuel manufacturers are continually changing their formulas, made testing MOGAS unreasonable. Use MOGAS at your own risk, as you would with any other ignition.
There was a mention of a "blip" during an ignition check. This has been an issue with the Bendix style ignition switches. They will sometimes ground both ignitions as you switch between left and right. This will momentarily reset the Surefly (miliseconds), resulting in the blip. Buying a new switch may not help.
I just returned from a hot summer, high DA trip to Durango, CO and Great Falls, MT. I had good power, but can't compare to the Slick as I never flew the airplane up there on the Slicks. With the airplane heavy, 11,500', 50° LOP, I was cruising at 6.2gph at 155 knots TAS.
I can tell you that most of the "issues" with the Surefly are the result of installation errors, or bad electical/ignition systems:
Not timing at TDC
DIP switches incorrect
Capping the MP line when in fixed timing (MP sensor will through a fault code as the cap will overpressurize the sensor)
Non-compliance with the uninterupted power source requirment. If you wire through a CB or a relay that provides a dirty electrical signal, the unit may not like it. Wire it directly to the battery, per the manual.
Poor grounding of the engine (Surely uses the engine case as a ground)
Bad spark plugs
Bad ignition wires
The list goes on. Most of the units returned, pass bench test. Obviously, there are occasional issues with a unit.
I'm a believer in the company, especially as a witness to what the FAA has put them through. The unit was tested at least 7X more than the competitors.
Anyway, my 2 cents worth.
BTW, if you want to be able to test and tune your ignition curve, the E-MAG guys are neighbors and have a great product, as well.
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