New Eggenfellner Performance Numbers

[Top_prop]

Just lurking on in this post, quietly learning about the Egenfellner packages and seeing an intelligent discussion marred by one post, got me alarmed... not typical of my limited experience on this forum... but

I'm glad to see Delta Romeo's post above... hopefully this can get back to a discussion of technical merrit, real world data, and actual experiences with an interesting product and its developer.

Tom

[hevansrv7a]

RV-7A. SJ cowl, plenum and pants. Superior 180 hp FI, Catto 3-blade course pitch.

169 kts 9.0 ghp LOP WOT 8500' DAlt. This is 75% using Walter Atkinson's formula for HP from FF when LOP. It will do 175 kts for another GPH.

Jan's doing better if his numbers are as accurate as mine (GPS 3-way calibration of GRT TAS)

[rv6ejguy]

Originally Posted by hevansrv7a

RV-7A. SJ cowl, plenum and pants. Superior 180 hp FI, Catto 3-blade course pitch.

169 kts 9.0 ghp LOP WOT 8500' DAlt. This is 75% using Walter Atkinson's formula for HP from FF when LOP. It will do 175 kts for another GPH.

Jan's doing better if his numbers are as accurate as mine (GPS 3-way calibration of GRT TAS)

That's very nice but I believe the poster was looking for others flying the Egg engines with some real world numbers.

[David-aviator]

Originally Posted by rv6ejguy

That's very nice but I believe the poster was looking for others flying the Egg engines with some real world numbers.

Here are some numbers I posted on the EGG forum in August of 2004.
(note: I have since come to believe the MT-7 prop is not optimal for the engine. The MT-7 was certified with the Cessna 152 on 27APR92. How it came to be the prop of choice with the Subaru engine for a couple years I know nothing about, except as I say, I do not believe it is optimal for the H6 engine. The new Sensenich prop would produce different numbers.)

At 12,500', OAT 53?F.

RPM 2600/4830 (prop/engine)
BURN = 10.1
TAS = 148 KTS (170 MPH)
MPG = 16.83 (Still Air)

RPM 2500/4590
BURN = 9.3
TAS = 146 (168)
MPG = 18.06

RPM 2400/4350
BURN = 8.5
TAS = 144 (166)
MPG = 19.52

RPM 2300/4160
BURN = 7.8
TAS = 140 (161)
MPG = 20.64

RPM 2200/3970
BURN = 7.1
TAS = 135 (156)
MPG = 21.97

RPM 2100/3780
BURN = 6.8
TAS = 133 (152)
MPG = 22.35

RPM 2000/3580
BURN = 6.0
TAS = 127 (146)
MPG = 24.33

RPM 1900/3400
BURN = 5.5
TAS = 125 (144)
MPG = 26.18

RPM 1800/3200
BURN = 5.1
TAS = 122 (141)
MPG = 27.64

RPM 1700/3090
BURN = 4.9
TAS = 114 (132)
MPG = 26.93

The 2600 2500 2400 2300 2200 RPM numbers at 8,500' are as follows:

RPM 2600/4830
BURN = 12.2
TAS = 151 (174)
MPG = 14.26

RPM 2500/4620
BURN = 11.2
TAS = 152 (175)
MPG = 15.62

RPM 2400/4340
BURN = 10.1
TAS = 149 (171)
MPG = 16.93

RPM 2300/4160
BURN = 9.6
TAS = 146 (168)
MPG = 17.5

RPM 2200/3970
BURN = 8.6
TAS = 141 (162)
MPG = 18.83

I recorded numbers down through 1700 RPM again and they were slightly less efficient than the previous flight, probably due to a colder temperature and heavier airplane with full tanks. I did not record numbers at 2700 RPM because the engine still stumbles a bit at that RPM. I do not know what is causing it. The engine just hesitates a bit now and then at 2700. It is smooth at all other RPMs, the smoothest being 2300.

Today I finally determined what was causing a strange noise at 1700 RPM - it is the left muffler hanger. It needs to be tightened. When I put my shoe on it on the cabin floor, it became quiet. That was a good feeling as that noise had been of some concern.

As stated in a previous message, there's some work to be done to reduce drag. This airplane ought to going faster than it is at the top end.

dd
RV-7A
H6