Surefly Dual SIM

[N442PT]

Just Finished the install of my dual Surefly SIM last night. The first start and ground run up was a noticeably smoother running engine and much faster start up. I will be test flying this weekend and will post some updates. 

[NickG]

How did they handle the battery back up? Very interested to hear about your dual sim setup. How elaborate was the install?

[LANCECASPER]

I could see having one Surefly SIM, since then you have two completely different ignition sources, but not two Surefly SIMs. Having a simple mag on the other ignition circuit seems like a nicer redundancy to me. Two independent technologies, backing one another up.

But maybe that's just me, since for my attitude indicator I have a spinning electric gyro backing up a glass panel, backed up by a tie-breaker Dynon D3. Three different companies. I would never consider having the same electronic AI running the same software backing up the other. 

[NickG]

What are the benefits, if any of having 2 SIMS vs 1 + legacy Mag?

[Marc_B]

  On 7/12/2024 at 7:22 PM, NickG said:

What are the benefits, if any of having 2 SIMS vs 1 + legacy Mag

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2400 hr TBO, no 500hr IRAN,, no drift requiring routine timing adjustment, no need for upper deck pressurized mag leading to mag corrosion concerns for turbo applications. 

But the cons of battery power dependence and no robust field experience yet to say how many hours it takes for any issues with the Surefly to manifest...those keep me with a single SIM to try to capitalize on the best of both worlds. 

[NickG]

  On 7/12/2024 at 7:43 PM, Marc_B said:

2400 hr TBO, no 500hr IRAN,, no drift requiring routine timing adjustment, no need for upper deck pressurized mag leading to mag corrosion concerns for turbo applications. 

But the cons of battery power dependence and no robust field experience yet to say how many hours it takes for any issues with the Surefly to manifest...those keep me with a single SIM to try to capitalize on the best of both worlds. 

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What about the discussions regarding increased CHT’s?

[Will.iam]

  On 7/12/2024 at 10:53 PM, NickG said:

What about the discussions regarding increased CHT’s?

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N/A for turbo application as the surefly can’t be retarded like in non turbo engines which is what increases the cht. 

[NickG]

  On 7/14/2024 at 5:45 AM, Will.iam said:

N/A for turbo application as the surefly can’t be retarded like in non turbo engines which is what increases the cht. 

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Right, but this is the Ovation forum so no Turbos here…

[Will.iam]

  On 7/14/2024 at 2:36 PM, NickG said:

Right, but this is the Ovation forum so no Turbos here…

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And yet you replied to marc_b quote in this supposedly no turbo forum where he specifically stated “turbo applications”

And you asked about elevated cht’s had you just asked in general I wouldnt have commented but you replyed to his quote with the turbo comment, hince why i made the comment. 

[NickG]

  On 7/15/2024 at 7:05 AM, Will.iam said:

And yet you replied to marc_b quote in this supposedly no turbo forum where he specifically stated “turbo applications”

And you asked about elevated cht’s had you just asked in general I wouldnt have commented but you replyed to his quote with the turbo comment, hince why i made the comment. 

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True, that.

However, I'd still like to hear from folks with O's and Dual or single SIMS about the CHT issues (if any)

[Pinecone]

  On 7/14/2024 at 5:45 AM, Will.iam said:

N/A for turbo application as the surefly can’t be advanced like in non turbo engines which is what increases the cht. 

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FTFY

[NickG]

So what about the CHT increases. I fly in the southwest and here in Vegas my CHTs are hot, although manageable. If a SIM makes my CHT’s run hotter, I probably don’t want one.

[Will.iam]

  On 7/21/2024 at 11:42 PM, NickG said:

So what about the CHT increases. I fly in the southwest and here in Vegas my CHTs are hot, although manageable. If a SIM makes my CHT’s run hotter, I probably don’t want one.

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If your number one priority is cht temps, then leave the surefly in fixed timing and enjoy not having to overhaul it every 500 hours. The variable timing doesn’t start until a lower MP so on takeoff there should not be any difference than when you fly now. Once you get up higher in altitude at some point, (there used to be a graph that showed when the surefly started advancing the timing) there should be cooler air to help but some people don’t seem to see that. I would try it in variable timing and if you don’t like it switch the dip switch setting to fixed. 

[N201MKTurbo]

While it is true that the air gets cooler as you climb. it also gets less dense which reduces its ability to transfer heat. My observation is if the temperature is hot on the ground, and you are running hot, it doesn't get any better at altitude. You have to look at how much you are above the ISA temperature on the ground, you will probably be close to the same differential at altitude.

[NickG]

  On 7/22/2024 at 1:28 PM, N201MKTurbo said:

While it is true that the air gets cooler as you climb. it also gets less dense which reduces its ability to transfer heat. My observation is if the temperature is hot on the ground, and you are running hot, it doesn't get any better at altitude. You have to look at how much you are above the ISA temperature on the ground, you will probably be close to the same differential at altitude.

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Typical flight yesterday at 8500 ft - OAT 20c thats +21 ISA

[N201MKTurbo]

  On 7/22/2024 at 5:04 PM, NickG said:

Typical flight yesterday at 8500 ft - OAT 20c thats +21 ISA

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Is that damn hot or f’in hot? And you live in the cool Vegas not the hot Phoenix. (-:

Well, I just checked and KPHX and KLAS are both +38

[NickG]

  On 7/22/2024 at 6:28 PM, N201MKTurbo said:

Is that damn hot or f’in hot? And you live in the cool Vegas not the hot Phoenix. (-:

Well, I just checked and KPHX and KLAS are both +38

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I believe its damn f*ing hot in Vegas AND PHX. But if you want to even kick that up a notch, check the temps at KIFP.

[N201MKTurbo]

  On 7/22/2024 at 8:06 PM, NickG said:

I believe its damn f*ing hot in Vegas AND PHX. But if you want to even kick that up a notch, check the temps at KIFP.

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Laughlin and Vegas are the same right now. And you are 4 F hotter then we are....

[BlueSky247]

Sure would be interesting to see how these would work on the A3B6D, assuming they ever offered one in that configuration.

[N201MKTurbo]

  On 7/22/2024 at 8:35 PM, BlueSky247 said:

Sure would be interesting to see how these would work on the A3B6D, assuming they ever offered one in that configuration.

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It doesn't seem like it would be much of an engineering challenge to build one. I think getting approved for a dual installation is the first step. Once the world gets comfortable with that, I don't think much would stand in the way. I wonder how big the market is? 

[LANCECASPER]

 

[wcb]

I am having higher CHT at ROP with my Dual Surefly Setup (310 HP Ovation).  I posted somewhere else the same basic thing.  I am running over 400 degrees on my hottest cylinder.  LOP is great but sometimes I want to run ROP.  I bought a fast plane to go fast! 

 

Just this last weekend I had roughly 1500 nm trip from Texas to Maine (then back on Monday) and had the chance really to look at all different levels of ROP and none were able to work due to cylinder head temps getting over 400!

 

LOP was great at best all the way down to 10.1 gph at one point.  Still LOP is CHT is hotter than when I was with simple mags.

[N201MKTurbo]

I'm no expert on the SIMs. But, can't you set them up for fixed timing? It seems like that is what you want. If it is advancing the timing, it will make more power. more power means more heat. A Carnot engine cannot make more power without making more heat. With no variable advance, you will make the same power as a mag and get the same CHTs. Also, you should be able to reduce the power by reducing the MP and get the same power with the advance and use a little less fuel.

[Ragsf15e]

  On 8/8/2024 at 10:02 PM, wcb said:

I am having higher CHT at ROP with my Dual Surefly Setup (310 HP Ovation).  I posted somewhere else the same basic thing.  I am running over 400 degrees on my hottest cylinder.  LOP is great but sometimes I want to run ROP.  I bought a fast plane to go fast! 

 

Just this last weekend I had roughly 1500 nm trip from Texas to Maine (then back on Monday) and had the chance really to look at all different levels of ROP and none were able to work due to cylinder head temps getting over 400!

 

LOP was great at best all the way down to 10.1 gph at one point.  Still LOP is CHT is hotter than when I was with simple mags.

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Change the dip switches on the sf back to fixed timing.  I bet you have some baffle issues as well causing the problems, but fixed timing will take the advance out of the equation.

[N442PT]

Ok so I have 20 hrs on the dual Sim install. My Ovation has a second battery so my A&P wired them independently to each battery. Most of my flying is 8-10k and I always run ROP. On the initial flight I climbed to 8k, leveled off and leaned to 50 ROP. CHT's went nutz  hitting 420 degrees in minutes. After contacting Surefly I was told that the variable timing did not really work well with ROP flying. Decided to switch to fixed and everything went back to normal. Saturday on a long cross country flight Battery #2 failed. The result was exactly the same as the magneto that failed which is why I decided to go with the Surefly.  It was a hard bump followed by normal power and than about every 3 min another had bump. Not knowing what was wrong in air, I diverted to the closest airport to check it out. When I did a mag check Sim #2 shut down immediately. To get back home I transferred Sim#2 to Battery 1 and made it home with know issues. Looking back on my decision I would not do it again. I will send my mags off for overhaul and keep handy just in case.  

So here is my takeaway pros & cons 

• Very smooth engine performance
• Will be looking for a standby battery power gauge to monitor both battery voltages 
• No performance difference seen at this point 
• Hot starts are much better
• Faster cold start