Surefly electronic ignition

[DanH]

Originally Posted by Toobuilder

And to ask Dan for clarity - with your RV-8 side by side comparison, was the other ship an angle valve like yours?

No, a parallel valve. It should have responded to advance better than an angle valve. An angle valve with a base timing of 28 and a full advance of 38 would even less happy, although I'm sure somebody has tried.

I just flew the RV cross country yesterday with the SDS system replacing the Pmags and can attest that the AV engine responds very differently than the PV (Rocket) I'm used to.

Yeah, that's what the 390 guys have been trying to tell you. For P-Mags, install the jumper, then clock it 5 degrees at installation. For Surefly, I'd set the DIP switches ON-OFF-ON-OFF (22 fixed) or OFF-OFF-OFF-OFF (18 base advancing to perhaps 31 max). SDS and EDIS, program as desired, same timing range.

[Toobuilder]

Yep, I actually flew the -8 (angle valve) with the jumper "out", and set to TDC for a few years. It was only after playing with the SDS CPI in the Rocket that I got the slap in the face of reality... When it comes to timing, "more" is not always "better". And the increased CHT is not necessarily because the engine is making "more power"... It might just be eating itself.

Right now I have the CPI set to retard timing on TO and I'm seeing about 17 degrees at my 2600 MSL strip. Yesterday, I took off heavy and in 97 degree heat. I climbed aggressively to 9500 cruise (at first, to clear some Delta airspace), yet never saw more than 360 CHT on my hottest cylinder. Have not seen any cruise performance increase yet, but the retard I have programmed is paying dividends already.

[pecanflyboy]

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.

$

[Sam Buchanan]

Originally Posted by pecanflyboy

I can tell you that most of the "issues" with the Surefly are the result of installation errors, or bad electical/ignition systems:

Capping the MP line when in fixed timing (MP sensor will through a fault code as the cap will overpressurize the sensor)

This was the only glitch in my installation of the SureFly. The docs with my unit said to cap the manifold pressure port if using fixed timing....which I did. The device wouldn't time properly and the nice guy at SureFly asked me if the pressure port was capped. Of course it was per the instructions.

I was informed the port cannot be capped because it confuses the software. I hope the documentation has been revised since then. My unit timed perfectly after the port was uncapped.

[pecanflyboy]

Originally Posted by Sam Buchanan

This was the only glitch in my installation of the SureFly. The docs with my unit said to cap the manifold pressure port if using fixed timing....which I did. The device wouldn't time properly and the nice guy at SureFly asked me if the pressure port was capped. Of course it was per the instructions.

I was informed the port cannot be capped because it confuses the software. I hope the documentation has been revised since then. My unit timed perfectly after the port was uncapped.

As you mentioned, if you cap the MP port with a rubber cover or a thread protector, you might presurized the MP sender to the point that it sends a rapid flashing light on the LED. This is an indication of a fault, in this case excessive MP. In the current installation manual, there is no mention of using a cap on the MP port. Probably worth putting in the troubleshooting guide.

$

[DaveN]

I just replaced a Slick impulse-coupled mag with a SureFly unit. There was nothing in the STC documentation to direct capping the MP port, so I didn’t. The unit timed perfectly to the engine. Based on a number of forum opinions on advance timing, I elected to stick with fixed 25 deg BTDC timing. No issues whatsoever with install or operations.

[pecanflyboy]

Originally Posted by DaveN

I just replaced a Slick impulse-coupled mag with a SureFly unit. There was nothing in the STC documentation to direct capping the MP port, so I didn’t. The unit timed perfectly to the engine. Based on a number of forum opinions on advance timing, I elected to stick with fixed 25 deg BTDC timing. No issues whatsoever with install or operations.

I hope that once you have some inflight experience, you set the opinions aside and take advantage of the variable timing mode. The fact is that no one has had a catostrophic detonation event in variable timing with the Surefly.

[DanH]

I don't think anyone is concerned about detonation.

[pecanflyboy]

Originally Posted by DanH

I don't think anyone is concerned about detonation.

What is the concern?

[DanH]

Originally Posted by pecanflyboy

What is the concern?

To be clear, we're talking about advance here, not product. There's much to like about the product.

Regarding advanced timing, for the average user the downside is higher temperatures for little return.

For the advanced user, no published advance schedules.

Is variable advance a bad thing? Of course not. It can be a useful tool.

You have a thread going right now:

https://vansairforce.net/community/s...0&postcount=17

Set your switches to fixed timing, and see what happens.