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Flying a 14 / 14a?

RV-14A stock 390 60 EXP. 9500’ WOT 2300 RPM and 50 LOP I get 8.2 to 8.4 GPH at 161 kts. I can get 167 kts at about 9GPH a little less lean and 2400RPM
 
RV14 data

Hello Jay,

I typically fly at PEAK and 23BTDC

9000DA WOT and 2400RPM is 175KTAS +/-3kts at 9.5gph
Every 2000’ is +/-0.5gph. In other words, 11,000DA is 175KTS at 9gph and 7,000DA is 10gph.
50LOP is about a gph saved, but about 5-7 kts slower.
100ROP is about 2.5gph more and about 5-7kts faster.

The 50LOP speed loss can be reduced a bit at 28BTDC.
 
Hello Jay,

I typically fly at PEAK and 23BTDC

9000DA WOT and 2400RPM is 175KTAS +/-3kts at 9.5gph
Every 2000’ is +/-0.5gph. In other words, 11,000DA is 175KTS at 9gph and 7,000DA is 10gph.
50LOP is about a gph saved, but about 5-7 kts slower.
100ROP is about 2.5gph more and about 5-7kts faster.

The 50LOP speed loss can be reduced a bit at 28BTDC.

Mine the same.
 
These numbers jivs with what I see. My EXP119 is a bit faster and a bit thirstier but more or less the same.
 
This thread should be sticky-ed with a new title.... Are bigger engines less fuel efficient?
As the above reports show, if when comparing RV's with smaller engines to those with larger engines, if the additional speed (which means less actual flight time between two points) is taken into account, and the bigger engine is operated in an mode more biased towards economy (vs getting every single knot of speed possible), the actual fuel usage between a small engine and large engine RV is very similar.

I'm not saying they will be exactly the same but the difference will be very minor compared what most people think.

Put in a more specific way, if you built two nearly identical RV-7's with constant speed props and the only differences being that one had a 160 HP O-320 and the other had an IO-390 EXP119, if the mixture was managed the same (both flown at peak EGT and same RPM for example), and the throttle was reduced on the 390 to match the speed of the 320 airplane, the fuel used for the flight would be very close to the same for both airplanes.
 
I wish I got that good a fuel flow

flying at 7500 wot 2400 rpm and 50 LOP I'm getting about 11 gal per hour and 150 TAS. Seems like once I go to WOT the fuel flow stays around 11 mph. I haven't been above 12500.
 
flying at 7500 wot 2400 rpm and 50 LOP I'm getting about 11 gal per hour and 150 TAS. Seems like once I go to WOT the fuel flow stays around 11 mph. I haven't been above 12500.

Way slow for that fuel burn.

This may be a fuel flow measuring error - did you mount the red cube per the firewall forward instructions?

On the RV-14A I helped with this problem at ~7K’ or so fuel flow went to about 11GPH no matter what you did with the mixuture control. The problem was resolved when we moved the cube off the engine (like the instructions say).

So - does you fuel burn match how much gas you are putting in the plane?

Carl
 
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Here's a pic from a flight this week. I'm running pretty close to peak EGT at this altitude and dual PMAGs. All the other relevant data is in the photo.
 

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