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  #1  
Old 07-10-2012, 08:52 PM
Wesael's Avatar
Wesael Wesael is offline
 
Join Date: Feb 2009
Location: Brooksville
Posts: 282
Default N45678 Cruise testing

I have been working and refining little details of the School Bus.

Worked on the fuel system a little last week and seem to have it dialed in a little better now.



This was after about 60 miles of level flight with the a/p flying and everything stablized.

Fuel flow is 11.8 running 179kn TAS at this altitude LOP. I am still testing and contemplating tuning #5 cyl as you can see it is quite a bit leaner than the rest of them and is always the first to peak.

It appears to make about the same speed on approx .4-.5 GPH less with each 1000ft of increase in DA but I have not yet made a chart to reflect that. I might do it in the future.

Sorry about the picture being choped off at the top. It is running 23.4in MP.
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  #2  
Old 07-11-2012, 11:32 AM
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blahphish blahphish is offline
 
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Location: Marietta, GA (KCZL)
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Default

Thanks for sharing this. As a fellow Skyview owner, its neat to compare how other people have chosen to configure the layout of the screen. Looks like you're getting some great numbers.

I notice your indicator near the MP gauge says PK (peak), yet obviously you are a little LOP. I have found that mine dont always exactly correlate right on spot too. At least I know I'm not alone now.

I'm trying to learn more about LOP operation and I know this is a primer war type subject but never the less, here we go! Best that I have recently come to understand it, with 70% power you would want to run more LOP than -04F. Should be closer to 25. What are your thoughts on this matter? See 'red box' concept below. Just curious because in mine I have a hard time hitting 25 on all cylinders before it loses drastic amounts of power and/or runs rough. I'm sure I could benefit from some tuning. I'm still learning about all this and so lets keep this educational!

Red Box = No Fly Zone

At and below about 60% power, there is no red box. Put the mixture wherever you want it.
At about 65% power or so, 100ºF ROP to Peak.
At about 70%, 125ºF ROP to 25ºF LOP.
At about 75%, 180ºF ROP to 40ºF LOP.
At about 80%, 200ºF ROP to 60ºF LOP.
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  #3  
Old 07-11-2012, 12:47 PM
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pierre smith pierre smith is offline
 
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Location: Louisville, Ga
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I'm with both of you guys on this and until I went up to Airflow Performance and had Don Rivera fly with me and record EGT's and fuel flows, I couldn't run LOP successfully either. We then balanced the 6 EGT's with an assortment of different orifices.

My middle two cylinders have a slightly larger fuel injector orifice to better match the other four cylinders and now, running the leanest cylinder LOP at 50 deg LOP gives me six pretty closely matched EGT's...all LOP and around 11.4 GPH.

That said, it costs me around 12 MPH TAS compared to running ROP. However, my range goes from 800 miles to over 1,000 miles and time goes from 4 hours to near 5 1/2!

I told my wife that we could make Osh non-stop and have 45 minutes reserve but she said, "Nope...we need to stop and stretch

Best,
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  #4  
Old 07-12-2012, 07:48 AM
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NovaBandit NovaBandit is offline
 
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Thanks for the data points. I love reading about these real world performance numbers, and how they compare to the other planes I'm flying now:

C182: 145Kts @ 14GPH (~12MPG no wind)
Piper Archer 110Kts @ 9GPH (~14MPG no wind)

It's good validation of my decision to build the -10, and motivation to GET IT DONE! I've been seeing -10's reportedly getting between 16-21+ MPG depending on how fast people are pushing them.
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  #5  
Old 07-12-2012, 10:07 AM
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pierre smith pierre smith is offline
 
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Ed, speaking of MPG, it's usually around 13-15 running 75% and ROP. It easily goes above 16 MPG running around 68% and LOP in light wind conditions. I have seen over 20 MPG with strong tailwinds as well.

My personal philosophy says that flying's never really inexpensive and since I like the speed, I'd rather spend more and true 202 at 12-14 MPG

A good time to capitalize on economy and LOP ops is when you have a 25-40 knot tailwind!

Best,
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  #6  
Old 07-12-2012, 12:08 PM
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NovaBandit NovaBandit is offline
 
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Quote:
Originally Posted by pierre smith View Post
My personal philosophy says that flying's never really inexpensive and since I like the speed, I'd rather spend more and true 202 at 12-14 MPG
I agree. It's just nice having a number that you can tell non-aviation people, who don't have a concept of GPH and airspeeds, how efficient this plane is.
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  #7  
Old 07-12-2012, 09:20 PM
lancef53 lancef53 is offline
 
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Why do you run the fuel down so far on the one tank?

Very impressive--I need to stay away from this place or I am gonna end up building one!!
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  #8  
Old 07-12-2012, 10:24 PM
BobTurner BobTurner is offline
 
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I think Ed is using statute miles per gallon; Pierre nautical miles per gal.
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  #9  
Old 07-12-2012, 10:50 PM
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Wesael Wesael is offline
 
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Quote:
Originally Posted by blahphish View Post
I'm trying to learn more about LOP operation and I know this is a primer war type subject but never the less, here we go! Best that I have recently come to understand it, with 70% power you would want to run more LOP than -04F. Should be closer to 25. What are your thoughts on this matter? Red Box = No Fly Zone

At and below about 60% power, there is no red box. Put the mixture wherever you want it.
At about 65% power or so, 100?F ROP to Peak.
At about 70%, 125?F ROP to 25?F LOP.
At about 75%, 180?F ROP to 40?F LOP.
At about 80%, 200?F ROP to 60?F LOP.
Hey Brian good to hear from you. Dont take me as an example of how to run your engine! I sometimes swim upstream

Dan posted this: http://www.google.com/imgres?um=1&hl...9,r:0,s:0,i:76

This is testing done by Lycoming. Notice the intake air temp, Cyl head temp, MAP, and Oil Temp.

I know there is a chance that I am running "closer" to detonation than some like to go but like I said I sometimes swim upstream.

There will likely be a lot of people jump on here and "chew me out" but thats ok..it has happened before and it will happen again..... I can take it.

Also as noted by someone on PM. Dont get to overly excited about the calculated TAS on the Dynon.

I have made sure all of the inputs are calibrated properly but you can take the OAT, IALT and Berometic pressure and figure the DA from that and you will get a different DA than Dynon has....????? Whasup wit dat???? I asked Dynon what they use for a humidity value in the DA calculation but they have yet to provide me an answer. I assume it is something other than most of the other E6B calculators use. Whether it is closer to right or not I dont know. I do know that if I fly the 3 way course using Kevin Hortons method with the spreadsheet I get the same TAS that the Dynon is showing within a Knot.

Anyway if you use the DA from another E6B and calculate TAS from that and the IAS you will get about 2knots less per this picture.
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  #10  
Old 07-12-2012, 10:52 PM
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Wesael Wesael is offline
 
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Quote:
Originally Posted by lancef53 View Post
Why do you run the fuel down so far on the one tank?

Very impressive--I need to stay away from this place or I am gonna end up building one!!
I had a heavy right wing and I used fuel differance to see where it balanced and then made an adjustment to correct the heavy wing and on this flight I was re-checking to see how much change I had made.
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