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Will a Gallon make a Big Difference?


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1 hour ago, N231BN said:

There is also a procedure to adjust the auto-lean schedule to give you better climb FF.

Auto-Lean.pdf 845.69 kB · 2 downloads IO-550-A.pdf 165.34 kB · 1 download

THIS is the “root” of the problem here.  We have “by the book” purists that say “your fuel flow is too high” (based on the IO-550A Chart) for maximum sea level flow...as listed by Continental...vs. ACTUAL users that are NOT selling cylinders, but trying to operate their planes to reduce cylinder temps in climb...AND applications with 10HP more than Missile application that recommend fuel flow +-28GPH in Eagle application.  I don’t “think” I have an Auto-Lean issue as I am seeing elevated cylinder temps almost immediately in a VERY conservative cruise climb in our Missile.  Appreciate the information.  IF increase of a gallon doesn’t see noticeable improvement this is another area to “take a look at”.

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On 8/27/2020 at 11:14 AM, N56394 said:

My Missile @SL I do lean at idle for smoother running. Takeoff is full rich. Flying again later today and will report current flow full power takeoff full rich. Do you know if you have the altitude compensating fuel pump? I do have it. I have read a few Bonanza articles to remove it and put on the standard pump.

Any info to report?

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On 8/27/2020 at 12:48 PM, Missile=Awesome said:

Yes, please give elevation of airport and your fuel flow at full power on take off.  I am NOT a lean to EGT guy.  I don’t mess with mixture as I climb.  I get up there at max MP and mixture and I reduce RPM and run LOP in cruise.  Not sure if I have the altitude compensating fuel pump on my Missile.

I do not lean during climb. The mixture is auto leaning. My home airport is 539 feet so I consider it sea level even though it's a 500 feet higher.

-Seth

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On 8/27/2020 at 1:09 PM, N231BN said:
On 8/27/2020 at 12:48 PM, Missile=Awesome said:
Yes, please give elevation of airport and your fuel flow at full power on take off.  I am NOT a lean to EGT guy.  I don’t mess with mixture as I climb.  I get up there at max MP and mixture and I reduce RPM and run LOP in cruise.  Not sure if I have the altitude compensating fuel pump on my Missile.

Does your FF decrease as you climb or stay the same? If you have a standard pump and don't lean it you will be very rich in the climb at higher altitudes.

FF decreases as you climb in the Missile

 

Edited by Seth
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On 8/27/2020 at 12:56 PM, Missile=Awesome said:

EVERY OTHER Missile owner I have talked with is flowing 27.5 to 28 at take off power with elevations <2,000’.  My sampling is SMALL (three other owners), but the total Missile fleet is also small.  (We are #42 out of? I believe <60 total conversions)

You are one of the last conversions. It was mid 40s.

Corrected:  I was wrong. 55 as stated below.

 

-Seth

Edited by Seth
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On 8/27/2020 at 1:08 PM, Niko182 said:

Talk to guys that have A36's with the io550 conversion and ovations and eagles with the 310hp conversion. The engines are nearly identicle, and setup fuel wise is going to be the same.

No quite - part of the cooling is the cowling. The Bonanza is a bigger cowling, the Mooney is tighter.

On the 310 HP Cirrus SR22 G6 the FF at TO at sea level is anything under 30gph. 29.5-29.9 or so.

-Seth

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On 8/27/2020 at 1:16 PM, Missile=Awesome said:

Our fuel flow decreases with climb.  We must have the altitude compensating fuel pump.  I would WELCOME having more fuel flow in the climb and having option to lean manually.

Correct - we do have an altitude compensating fuel pump. It's actually a bladder that controls it. So technically it's also density altitude compensating. Another reason to have the setup more rich if it had to be, as you can always lean the mixture but can't richen it unless you want to run the boost pump.

-Seth

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4 hours ago, Niko182 said:

Isnt the K factor on most NA engines 14.9. Im confused what the 29.2 is. That sounds more like a fuel flow.

I think your confusing the LOP Fuel factor with the K factor. Never seen a K factor of 14.9, the transducers K factor is written on the transducer - nothing to do with the engine its installed on. Of course it should still be calibrated for the installation as its orientation and  the hose routing in and out will alter it slightly.

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13 minutes ago, kortopates said:

I think your confusing the LOP Fuel factor with the K factor. Never seen a K factor of 14.9, the transducers K factor is written on the transducer - nothing to do with the engine its installed on. Of course it should still be calibrated for the installation as its orientation and  the hose routing in and out will alter it slightly.

That is exactly what i was mixing it up with.

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Some people have mentioned which FF sensor they are using....

Often something called a red cube...

The K-factor is written on the side of it, or engraved...

As fuel flows through the sensor, the paddle wheel turns... often the sensor uses a a light and a receptor and wings on the paddle wheel interrupt the light...

The sensor sends blips of 0 and 1s to the instrument that counts the rotations over time... multiplies it by the factor... to convert to GPH...

Often, the K-factor is quite accurate...  none are perfect... because of installation and other reasons...

So... verify the FF numbers are correct, as well as total fuel used...

It is extra helpful to fill the plane the same way every time, on the same very level surface...

PP thoughts only, not a mechanic...

Best regards,

-a-

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9 hours ago, carusoam said:

Some people have mentioned which FF sensor they are using....

Often something called a red cube...

The K-factor is written on the side of it, or engraved...

As fuel flows through the sensor, the paddle wheel turns... often the sensor uses a a light and a receptor and wings on the paddle wheel interrupt the light...

The sensor sends blips of 0 and 1s to the instrument that counts the rotations over time... multiplies it by the factor... to convert to GPH...

Often, the K-factor is quite accurate...  none are perfect... because of installation and other reasons...

So... verify the FF numbers are correct, as well as total fuel used...

It is extra helpful to fill the plane the same way every time, on the same very level surface...

PP thoughts only, not a mechanic...

Best regards,

-a-

Yes.  We have a Shadin Totalizer (Mini-flo) unit.  You hold a button to SEE the K factor setting.  Now that tanks are sealed we have NO seepage issue to “cloud findings” regarding flow/fueling.  We will be fueling to 30 gallons aside.  This is essentially “full main tanks”, but with crossover of fuel into the AUX/Long range tanks.  This is a GOOD amount of fuel for balance of onboard and loading to ensure max take-off weight is NOT exceeded.  The EDM830 can/must be programmed for k factor.  I will be initially entering the 29200/29.2 as THIS is the value that I was told by Shadin that should be used.  The number showing on the Shadin test screen (as previously stated) is 28.6.  We have a “red cube” in reserve and when the Shadin fails we will switch to the red cube.  FYI the Red Cube we have FT-60 that has 68000 pulses does NOT have the K factor stenciled or applied ANYWHERE on the exterior of the unit.

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Some times, existing FF sensors start giving poor data...

Two common causes for bad data...

1) Stickiness... low count...

2) air bubbles... high count...

 

Then some others... less likely..

3) installation errors around MS have included the sensor being upside down... or angles in the tubing too sharp, or too close to the sensor... Or Anything that can allow a bubble into the system, and let it stay for a while...

4) Sensitivity to the installation issues may be increased during various segments of flight... 
 

Possible solution...

5) Some sensor issues have been known to be washed out... literally. Remove clean in a proper solvent and replace... anything that deposits on the lens can easily disrupt the count...

 

PP thoughts only, not a mechanic...

-a-

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I have the Electronics International FF and I set the K factor long ago (once I messed it up by changing to imperial gallons, ugh). I am confident that my flow numbers are good. filled my tanks several times and came out within a gallon between the pump and the FF.

Yesterday's flight data.

466 MSL take-off, 29.5 GPH full rich, WOT, 2700 RPM. climb to

1500 MSL climb, 22.8 GPH full rich, 25 MAP, 2550 RPM, 115 kts. EGTs approximately 1300, CHTs approximately 380.

could not do a full climb to get fuel pump leaning numbers will do when not so many clouds, lol

I ordered the GAMIs to fix my lean cyl 1 and 2. 

Cheers.

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3 hours ago, N56394 said:

I have the Electronics International FF and I set the K factor long ago (once I messed it up by changing to imperial gallons, ugh). I am confident that my flow numbers are good. filled my tanks several times and came out within a gallon between the pump and the FF.

Yesterday's flight data.

466 MSL take-off, 29.5 GPH full rich, WOT, 2700 RPM. climb to

1500 MSL climb, 22.8 GPH full rich, 25 MAP, 2550 RPM, 115 kts. EGTs approximately 1300, CHTs approximately 380.

could not do a full climb to get fuel pump leaning numbers will do when not so many clouds, lol

I ordered the GAMIs to fix my lean cyl 1 and 2. 

Cheers.

Are you manually reducing power and fuel flow at 1500’?

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3 hours ago, N56394 said:

I have the Electronics International FF and I set the K factor long ago (once I messed it up by changing to imperial gallons, ugh). I am confident that my flow numbers are good. filled my tanks several times and came out within a gallon between the pump and the FF.

Yesterday's flight data.

466 MSL take-off, 29.5 GPH full rich, WOT, 2700 RPM. climb to

1500 MSL climb, 22.8 GPH full rich, 25 MAP, 2550 RPM, 115 kts. EGTs approximately 1300, CHTs approximately 380.

could not do a full climb to get fuel pump leaning numbers will do when not so many clouds, lol

I ordered the GAMIs to fix my lean cyl 1 and 2. 

Cheers.

Why would your “full rich” fuel flow drop from a very high 29.5gph at 466’ to only 22.8gph@1500’?  Why also would the RPM drop to 2550 with only 1000’ of climb?

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Just now, Missile=Awesome said:

Why would your “full rich” fuel flow drop from a very high 29.5gph at 466’ to only 22.8gph@1500’?  Why also would the RPM drop to 2550 with only 1000’ of climb?

The fuel flow comes down to 22.8 because the prop gets pulled from 2700 to 2550 and the MAP gets pulled to 25 in.

Do doesnt climb at full power. He climbs at 25^2.

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Yes, I reduced power to a cruise climb of 115 kts, 25 MAP and 2550 RPM so fuel flow is reduced. I only use max power for initial take off to about 1000 AGL from sea level.  As I climb, I add back in throttle to keep 25 MAP until WOT, then monitor temps until cruise alt. Heading out this afternoon to do a climb and will report FF vs alt at full rich.

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