REFLECTOR:One Fast Velocity
Jim Sower
reflector@tvbf.org
Sat, 05 Jun 2004 20:15:58 -0400
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
>>
>>
>> _______________________________________________
>> 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
>
> _______________________________________________
> 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
>
>