I have a 165hp Franklin in my Cruisair and have never found a good set of numbers that show fuel burn for climbs and cruise. I have never trusted fuel gauges and prefer to rely on established burn rates. I have decided to do some testing and document the results on spreadsheets. Once I collect enough data, I will plug all the number into the spreadsheet.
My first test flight was to establish climb burn rates. I started, taxiied, took off and climbed to 10,000 feet on a full left tank. My airfield is at about 850' MSL. I initially climbed out at 85Mph until I hit about 4,000 feet, then did more of a "cruise climb" of around 95Mph. I leaned out periodically by ear. When I got to altitude, I switched over to the right tank for the return to my airfield. I did an idle descent back down to 3,500 and cruised for 20 minutes at 2600RPM. I then filled the tanks full again and got my burn for that evolution.
Initial climb findings:
Total fuel burned for start, taxi, launch and climb to 10,000 = 3.5 gallons.
Time to 10000 feet = 17.1 minutes
Climb burn rate = 12.5GPH
Rule of thumb = 1.2 gallons burned for every 3000 feet of climb.
Cruise @3500MSL, 2600RPM = 9.0 GPH, IAS 130MPH
Notes:
Franklin 165
McCauley Metal Prop
OAT at launch was 24F.
OAT @10,000 was 0F
Weight was 1875lbs
Initial ROC @ 1300FPM (cold air is great!!!)
If anyone has better numbers or an accurate fuel flow meter, I'd be very interested.
My first test flight was to establish climb burn rates. I started, taxiied, took off and climbed to 10,000 feet on a full left tank. My airfield is at about 850' MSL. I initially climbed out at 85Mph until I hit about 4,000 feet, then did more of a "cruise climb" of around 95Mph. I leaned out periodically by ear. When I got to altitude, I switched over to the right tank for the return to my airfield. I did an idle descent back down to 3,500 and cruised for 20 minutes at 2600RPM. I then filled the tanks full again and got my burn for that evolution.
Initial climb findings:
Total fuel burned for start, taxi, launch and climb to 10,000 = 3.5 gallons.
Time to 10000 feet = 17.1 minutes
Climb burn rate = 12.5GPH
Rule of thumb = 1.2 gallons burned for every 3000 feet of climb.
Cruise @3500MSL, 2600RPM = 9.0 GPH, IAS 130MPH
Notes:
Franklin 165
McCauley Metal Prop
OAT at launch was 24F.
OAT @10,000 was 0F
Weight was 1875lbs
Initial ROC @ 1300FPM (cold air is great!!!)
If anyone has better numbers or an accurate fuel flow meter, I'd be very interested.