Typical O-360-A1A Fuel Flows?
 

Looking for a sanity check on typical fuel flows for takeoff and cruise. I have the following configuration:

RV-7A
Lycoming O-360-A1A, 8.5:1 pistons, 180 HP
58 hours total time airframe and engine
2 Slick Mags.
Catto 3 blade

Just getting into final calibration of my EIS-4000 engine monitor with fuel flow. My fuel flow readings are way high and I would like to know what some of you are seeing.

Thanks,

Takeoff and early climb? Full power you might see fuel flows in the 16 gph range (I have to admit, I have never checked the calibration at that end of the measurement range - I can just say it's a LOT of fuel per hour - glad I don't stay there long...)

For Cruise, leaned out LOP at 8,000', 75% power (approx), I can get it down to about 8.0 +/- gph. I am usually within a gallon between my totalizer and what I read on my fuel receipts.

I worked on my own EIS FF calibration over the past two weeks, and the FloCal number I started with was 200 (recommended by Sandy at GRT). That turned out to be a bit high, so I modified it to 175, then 180. At 180, the EIS showed total fuel used after two and half hours of flying was about 1.5 gallons less than actual, so I will bump it up to 185 for the next check. With FloCal at 180, FF at cruise (24/2400, mixture leaned to 1400 deg EGT, at 3000 feet) was in the 9.5-10.0 range. Your numbers may be different because of different engine/carb/FloScan setup, but by adjusting the FloCal number and checking fuel used, you will eventually get it perfect for your airplane.

I have a Barrett O-360 with 9:1 pistons, and I plan for 10 gph block-to-block, and it is usually right on. I will see the 16-17 gph on climb, 9-10 enroute, or lower if up in the teens, and then 5-6 on descent. I use the VNAV for descents to make them long and efficient, usually setting up for pattern altitude 2-3 miles from the downwind entry.


Vic