SureFly on M20M

[skykrawler]

Browser search for SureFly installation on M20M TSIO-540 has no hits.   Has anybody had one installed on a Bravo wet head?

 

[Schllc]

30 minutes ago, skykrawler said:

Browser search for SureFly installation on M20M TSIO-540 has no hits.   Has anybody had one installed on a Bravo wet head?

 

@Danb

[alextstone]

Yet, I have.. Fire away with your questions.  I had reliability issues early on due to the voltage spikes.  That was corrected though and now my aircraft starts in half a rotation or less, hot or cold.  I did replace the ignition harnesses and installed fine wire plugs as well.  No change in power output as the mag timing is set to fixed though. 

[skykrawler]

Curious about the voltage spikes.  Is there a full time power source available at the engine end of the airplane? or was a wire run aft to the battery?  Where is the circuit breaker for your installation?

How did the pressurization connection to the SureFly work out?

[alextstone]

The power source was wired to the main bus on its own breaker... That wasn't the issue.  There is a circuit that shuts down the unit momentarily if it goes over I think 29 or 29.5 volts.  My voltage regulator was allowing for a momentary exceedance.  This became a known issue with some 28 v aircraft.  They first had customers install a buffer of some sort externally v then they added it to the internal circuitry.  Pressurization was never an issue...

[Danb]

3 hours ago, Schllc said:

@Danb

I did with great results 

D

[skykrawler]

21 hours ago, alextstone said:

The power source was wired to the main bus on its own breaker... That wasn't the issue.  There is a circuit that shuts down the unit momentarily if it goes over I think 29 or 29.5 volts.  My voltage regulator was allowing for a momentary exceedance.  This became a known issue with some 28 v aircraft. They first had customers install a buffer of some sort externally v then they added it to the internal circuitry.  Pressurization was never an issue...

 

 

Specifically.....

How was the power wire routed?  Down the left side of the cabin behind the interior trim?    Where on the panel was the circuit breaker installed?

We are going to provision for a dual SIM installation.

 

[alextstone]

 
 
Specifically.....
How was the power wire routed?  Down the left side of the cabin behind the interior trim?    Where on the panel was the circuit breaker installed?
We are going to provision for a dual SIM installation.
 

It was routed across the accessories area from left to right (it replaces the left mag) then through the firewall on the right side behind where the oil cooler is located then directly to the main buss in that side .

Does this help?

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[alextstone]

One more thing: I was not comfortable with the inline fuse setup that the MFGR recommended. I made the decision that I would rather have a CB in the cockpit instead

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[skykrawler]

8 minutes ago, alextstone said:

It was routed across the accessories area from left to right (it replaces the left mag) then through the firewall on the right side behind where the oil cooler is located then directly to the main buss in that side .

Does this help?

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When you say main bus - isn't that the bus switched on by the master?   The installation calls for a 'hot battery' connection - like the clock and cabin lights.

[Marc_B]

I have a Surefly installed in my M20K.  Wiring ran from the battery along the left side wall.  Personally I'd rather have a fuse back by the battery since the line is constantly hot.  My unit was Rev F.  Earlier revisions had a slower restart time when turned off which led to quirks on mag check.  Later versions had restart time sped up and you can't tell the difference between Surefly or mag now.  Additionally the voltage regulator/overvoltage circuitry on the Surefly was set lower on previous units which meant that random voltage spikes would reset the unit; this was addressed with the addition of a big capacitor that needed to be installed on the firewall.  More recent revisions remedied this.

On a turbocharged aircraft you can't take advantage of variable timing (which usually only applies to low MP settings anyways).  I think that's basically due to failure mode of MP line disconnect in flight levels with high power settings resulting in timing change and detonation. 

You don't "have to" but if you have a warranty claim I've heard that they recommend replacing spark plugs and wiring harness when you install the SureFly.  I was having issues with my right mag and my plugs were getting worn, so it was a no brainer for me.  Having a squared away ignition system has been great and allows me to smoothly fly deeper LOP.  Hot starts were never a problem but it starts easier still.

I'm not convinced that dual electronic ignition is the way to go yet.  I think a single Surefly is the "best of both worlds".  Pros of both without the cons of dependence on your battery or electrical system.

[alextstone]

When you say main bus - isn't that the bus switched on by the master?   The installation calls for a 'hot battery' connection - like the clock and cabin lights.

I see your concern now .. It has a dedicated power source

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[Will.iam]

5 hours ago, skykrawler said:

When you say main bus - isn't that the bus switched on by the master?   The installation calls for a 'hot battery' connection - like the clock and cabin lights.

I also have the surefly on an m20k. I put the fuse right next to the battery for the same reason as mark_c as i didn’t want a live wire down my side of the fuselage, i also however had a circuit breaker installed on the panel so when I’m parked away from home and a battery tender, i can pull the circuit breaker to keep the small drain the surefly pulls on the battery. I forgot once and started the engine with the breaker pulled. Found out when doing a mag check and surefly side was dead. Push back in the circuit breaker and all checked out after that i added “check surefly circuit breaker” to my preflight checklist. Have not had an issue since. 

[McMooney]

5 hours ago, skykrawler said:

When you say main bus - isn't that the bus switched on by the master?   The installation calls for a 'hot battery' connection - like the clock and cabin lights.

read the latest instructions,  there is a n option to run power from the hot side of the master relay.  you don't have to run a wire all the way to the batter, if you don't want.

 

 

[skykrawler]

27 minutes ago, McMooney said:

read the latest instructions,  there is a n option to run power from the hot side of the master relay.  you don't have to run a wire all the way to the batter, if you don't want.

Just read what is on their website:  Airframe (rev C).  Engine SIM6L (rev D) both documents have:

"For engines equipped with a single SIM: 1. The first SIM on an engine must be powered directly from the primary aircraft battery, and 2. The primary aircraft battery must be 10-30V and be able to provide a 10A peak current demand to the SIM."

I helped install one on a Piper Archer.   Had to install the TACH adaptor.  Was hoping there was a hot bus up front on the M20M, but apparently not.  My personal preference is a circuit breaker.  If the fuse fails in the back there is no recovery in flight.  The hardest part of the installation is the power source.

[Ragsf15e]

52 minutes ago, McMooney said:

read the latest instructions,  there is a n option to run power from the hot side of the master relay.  you don't have to run a wire all the way to the batter, if you don't want.

 

 

The master relay is the relay right next to the battery (in most applications).  It’s connected directly to the battery and is a relay/solenoid switched on by the master switch to provide power to the rest of the system (in general, because im no EE).  There’s a hot connection on the master relay for things like the clock or baggage light so they don’t require the master on.  You can connect your sf either to the battery or the hot side of the master relay, but either way you need to run a wire back there.  I have just had the fuse on mine for several years (F model) and it’s been fine.  I don’t really think there’s a reason to shut off the power drain away from home because it’s so small, one of our EEs figured it was something measuring months to actually drain your battery.  I haven’t had any issues.

[PT20J]

23 hours ago, skykrawler said:

Just read what is on their website:  Airframe (rev C).  Engine SIM6L (rev D) both documents have:

"For engines equipped with a single SIM: 1. The first SIM on an engine must be powered directly from the primary aircraft battery, and 2. The primary aircraft battery must be 10-30V and be able to provide a 10A peak current demand to the SIM."

I helped install one on a Piper Archer.   Had to install the TACH adaptor.  Was hoping there was a hot bus up front on the M20M, but apparently not.  My personal preference is a circuit breaker.  If the fuse fails in the back there is no recovery in flight.  The hardest part of the installation is the power source.

I believe the STC calls for a fuse, but a circuit breaker might be considered a minor modification. But that won't really help you because the fuse or CB needs to be located near the battery. It's purpose is to protect the wire between the fuse and the mag in case of a short somewhere. A fuse is simpler than a circuit breaker, so it should be more reliable unless you mount it in a high vibration location. 

[jetdriven]

You could mount a fuse off of the battery and a circuit breaker in the cockpit, but this is a lot of pieces of hardware in the circuit which introduces more points of failure… plus if the fuse blows you’re still in the same position where if you didn’t have a breaker.  
you can mount a circuit breaker right off of the hot side of the battery contactor but then if that trips you still can’t reset it in flight. So you just saved yourself the cost of a fuse, but then you have to mount the circuit breaker somehow in a manner where it’s secure from moving and where the terminals in the backside of it are protected. 
You could run the hot wire right up the side of the battery off of the contactor to the panel to your circuit breaker, but if anything chafes into that wire between the circuit breaker, and the battery, it’s going to likely catch your airplane on fire. Hence the reason for the STC saying that the fuse needs to be located as close to the battery as possible. The J model already has a fuse back there for the clock. 

[skykrawler]

b) Locate the 10A fuse (or other appropriate 10A circuit protection device) as close to the airframe battery as possible

[toomany]

A surefly was installed in our bravo today. we ran a 14ga. wire up the pilot side interior from the battery and brought it into the engine bay on the left side as close to left mag as possible. we installed 10a fuse in battery compartment and landed it on the master solenoid. we also used small diameter flexible air hose as a conduit for the 14ga wire - probably not needed but lessens the chance of a blown fuse if the wire chafes under the interior panels.
spoke to a couple installers that recommended 30 thousands gap on the fine wires - surefly website has dealer locater.
i'll post results/opinions after its back in the air


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[jetdriven]

IIRC Surefly reccommends stock gap, its Electroair who says .030"..

[toomany]

when i spoke to surefly they recommended 0025 - .0035 gap and fine wires. installers recommended .0030


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[MB65E]

Not on a Bravo but had the Lycoming version EIS (surefly makes them for lycoming) fail on a Cub 81h since new. Lycoming shows no stock. Only dealers can push for AOG parts after dealing with tech reps and troubleshooting is verified. I threatened to throw a set of slicks back on the airplane.
-Matt 

[Will.iam]

2 hours ago, toomany said:

when i spoke to surefly they recommended 0025 - .0035 gap and fine wires. installers recommended .0030


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as the new finewire spark plugs wear, the gap will become .0025-.0035. besides tempest warns against gaping as there is a higher risk of that "fine wire" snapping right off and you get to buy a new one.

[LANCECASPER]

8 hours ago, toomany said:

when i spoke to surefly they recommended 0025 - .0035 gap and fine wires. installers recommended .0030


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Do not gap fine wire plugs.