Hi,
I recently bought an RV-10 which has an IO540 that was rebuilt by Barrett Precision with 9:1 compression pistons. The injectors were tuned for high DA operations (since the previous owner was based at a high DA airport). A blurb from the POH:
"Each injector is tuned to ensure that all cylinders reach peak EGT at the same fuel flow. They are optimized for operation at high altitude with the fuel injector restrictors centered around 0.025” for increased pressure at the fuel distribution spider. For frequent flying at low density altitudes re-tuning around .028” restrictors may be advised."
My home airport is (nearly) at sea level. I had a pilot friend record a video at takeoff (I guess I could have obtained the same data by downloading the EFIS logs). With mixture at full rich and a WOT for takeoff, here's the data that was captured right after things stabilized after takeoff (probably at 400-500 AGL):
Power: 94%
Fuel flow: 25.1 gph
RPM: 2630
MP: 27.5
EGTs: 1245-1297
CHTs: 324-357
I have a few questions:
-is this power and fuel flow normal for this kind of engine on takeoff? I guess the other way of asking the question is what power and fuel flow do you see on takeoff in an IO540?
-Is this level of power and fuel on takeoff damaging to the engine and should I be considering using a lower throttle/mixture setting for takeoff?
-My practice is to back off the power at about 500 AGL to 24" MP/2500 RPM/18-19 gph for a cruise climb at about 125 KIAS. Any concerns on any of those numbers?
-Should I be seriously thinking about getting the fuel injectors re-tuned?
Thanks,
Vas
I recently bought an RV-10 which has an IO540 that was rebuilt by Barrett Precision with 9:1 compression pistons. The injectors were tuned for high DA operations (since the previous owner was based at a high DA airport). A blurb from the POH:
"Each injector is tuned to ensure that all cylinders reach peak EGT at the same fuel flow. They are optimized for operation at high altitude with the fuel injector restrictors centered around 0.025” for increased pressure at the fuel distribution spider. For frequent flying at low density altitudes re-tuning around .028” restrictors may be advised."
My home airport is (nearly) at sea level. I had a pilot friend record a video at takeoff (I guess I could have obtained the same data by downloading the EFIS logs). With mixture at full rich and a WOT for takeoff, here's the data that was captured right after things stabilized after takeoff (probably at 400-500 AGL):
Power: 94%
Fuel flow: 25.1 gph
RPM: 2630
MP: 27.5
EGTs: 1245-1297
CHTs: 324-357
I have a few questions:
-is this power and fuel flow normal for this kind of engine on takeoff? I guess the other way of asking the question is what power and fuel flow do you see on takeoff in an IO540?
-Is this level of power and fuel on takeoff damaging to the engine and should I be considering using a lower throttle/mixture setting for takeoff?
-My practice is to back off the power at about 500 AGL to 24" MP/2500 RPM/18-19 gph for a cruise climb at about 125 KIAS. Any concerns on any of those numbers?
-Should I be seriously thinking about getting the fuel injectors re-tuned?
Thanks,
Vas