S

SebsRV7A

Well Known Member
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Trying to figure out how close my cylinders are going over to LOP. I don't have fuel flow, so I'm looking for info on how much fuel flow changes in one complete turn of the mixture knob. Thanks! IO-360

Seb Trost
RV-7A
Boulder City, NV
 
What brand of injection??

Details man, need details.

I am pretty sure you will find different makes of injection units behave differently in this regard.

IO360, IIRC?
 
FWIW

When Don at Airflow was flying with me in the -10, he pointed out that each raised ridge on the mixture knob equals .2 GPH less as you lean to the next ridge up, on my IO-540 and the Dynon 100 pretty much confirmed that.

Best,
 
Seb,

My experience has been much like Pierre's. Bendix FI on an IO-540.

When leaning, I twist the knob a quarter turn at a time (thumb from 12 to 9 o'clock), then let it stabilize. Probably equals about a "ridge and a half". I typically see about a 0.3 gph FF drop with each 1/4 twist. Not always perfectly linear, but pretty close.

Might be 2/3 of that on a 360, but not sure...will be interesting to see what others say.

Cheers,
Bob
 
Trying for GAMI balance

When I had Mattituck build the engine, I opted for the flow matched cylinders to optimize for LOP cruise. GAMIjectors try to fix this problem (successfully)! but I tried to solve the issue in the build.
I have had great success with LOP ops, but without fuel flow, I didn't know the spread of the first and last to peak. It is half a turn of the mixture knob. Based on an extrapolation from the IO-540, I'd say I'm at .4 GPH. GAMI's target is .5 GPH, so it looks like I'm in the zone.
We flew from Baker City, OR to BVU in 3:50 and retopped the tanks. Burned 28 gal, so 7 and change including takeoff and climb. Makes $6 gas a bit less painful.

Seb Trost
RV-7A
Boulder City, NV
 
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