REFLECTOR:One Fast Velocity

Scott Derrick reflector@tvbf.org
Sun Jun 6 02:36:09 CDT 2004


Jim,

How about compression?  Mine is a 200HP IO360, is yours a 180?  That would 
explain the reduced fuel burn.

I've tested my fuel flow gauge against actual usage and its pretty darn 
close. I also fly with a TAS airspeed indicator, that was calibrated last 
year....

Maybe your injectors are better balanced?

Scott

At 06:15 PM 6/5/2004, you wrote:
>I have a std. FG with no wheel pants (yet), an IO-360 with Catto 
>3-blade.  I like 10k' but usually end up at 8k +- 500 on cross country.
>I make about 150 KTAS at WOT, 2650-2700 rpm leaned juuuust LOP at 8.0 - 
>8.2 gph.  How come my fuel burn is so much lower??
>
>
>Scott Derrick wrote:
>
>>I routinely cruise around 10,000ft, 2700 RPM,  9.5 GPH at 170-175 
>>KTAS(depends on temp)
>>
>>Std-RG, IO360 with a fixed pitch Catto prop.  If I had an adjustable I 
>>could go faster at a higher burn.
>>
>>Scott
>>
>>At 09:25 PM 6/1/2004, you wrote:
>>
>>>On Monday I went up with my friend Mike Deeter to collect some flight
>>>performance data.
>>>I must say that the Franklin and IVO prop make a screaming combination for
>>>not a lot of $$$.
>>>Its a standard elite RG.  Carbureted/magneto Franklin, electric IVO.
>>>Nothing special.
>>>
>>>I wanted to get more data, but clouds below 5000 was a problem.
>>>
>>>The best speed we saw was at 7500 feet altitude, full throttle, the first
>>>altitude where we actually
>>>achieved full open throttle.
>>>182KTS TAS, 2520 RPM, 23.1 inches MAP, 12.4GPH.
>>>
>>>I was more impressed however, with putting more pitch in the prop.
>>>At this
>>>same altitude, I took data at progressively slower RPM's (same throttle).
>>>174KTS TAS, 2300 RPM, 23.5 inches MAP, 10.8GPH.
>>>
>>>We stabilized a climb through 8000 feet at 120 kts indicated, 144kts true at
>>>700FPM rate.
>>>
>>>Levelling at 9000, going through various MAP/RPM settings, I was impressed
>>>by the economies achieved:
>>>         KTS TAS RPM     MAP     GPH
>>>1       147             2370    19.7    9.5
>>>2       180             2520    21.8    12
>>>3       175             2400    21.9    11.2
>>>4       162             2200    22.1    9.9
>>>
>>>At line 1, this is at 120 kts indicated (where I started data collection),
>>>147TAS.  This is partial throttle operation.  Not bad for 9.5GPH, but look
>>>at line 4, full throttle, slower RPM.  Faster speed, with just a little more
>>>fuel flow.  I find it surprising that pumping losses account for a 5%
>>>penalty between lines 1 and 4.  That's 15.5 nautical miles/gal and 16.4
>>>nautical miles/gal for lines 1 and 4.
>>>
>>>The most economical was at 7500 feet:
>>>174KTS TAS      2300RPM 23.5MAP 10.8GPH, making that 16.1 nm/gallon.
>>>I don't
>>>know why I didn't get at data point at 2200RPM.  It would have been better
>>>yet.
>>>What this says to me is pick a MAP/RPM combo that is the economy setting you
>>>want, then fly the altitude that will give you that power setting at WOT.
>>>
>>>It was hot too.  95F on the ground, adding about 3000' for density altitude.
>>>I love this stuff.  Can't wait to go back up and get more data to fill out
>>>the chart.
>>>This data makes flying a Warrior look expensive.
>>>
>>>  Brian Michalk  <http://www.michalk.com>
>>>Life is what you make of it ... never wish you had done something.
>>>Aviator, experimental aircraft builder, motorcyclist, SCUBA diver
>>>musician, home-brewer, entrepreneur and barely single
>>>
>>>
>>>_______________________________________________
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>>
>>
>>
>>"Those who sacrifice freedom to get security, deserve neither."
>>- Benjamin Franklin
>>
>>_______________________________________________
>>To change your email address, visit 
>>http://www.tvbf.org/mailman/listinfo/reflector
>>
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>>
>
>_______________________________________________
>To change your email address, visit 
>http://www.tvbf.org/mailman/listinfo/reflector
>
>Visit the gallery!  www.tvbf.org/gallery
>user:pw = tvbf:jamaicangoose
>Check new archives: www.tvbf.org/pipermail
>Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>


"Those who sacrifice freedom to get security, deserve neither."
- Benjamin Franklin




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