I’m getting 36-38 GPH take off flow on my TSIO-550E. I was told this is too low but I don’t believe it. If its higher than 38 it may cause a problem during take off at some higher altitude airports or when changing from LOP during landing….just my opinion.
John C. Bohn
N28487 4P
Direct (Cell)- 503-887-2933
I found an article for Cirrus SR-22 owners suggesting that the take off fuel flows on the IO-550N are set too low at the factory.
As I recall the Continental fuel injection document calls for about 26 GPH full rich full throttle, 2700 RPM.
The Cirrus article recommended a minimum of 28 GPH to help lower peak cylinder temperatures and pressures. Climb full rich, and then do the "big pull" with the mixture knob all the way into LOP territory. The table below shows how far to pull as a function of power setting.
Lean of peak for the IO-550 N (8.5 compression ratio) horsepower is 15 times fuel flow in gallons per hour. This was the basis of the LOP flow rates in the table above. I figure that with 10:1 compression which produces about 4-5% more horsepower, the number is about 15.6 horsepower per gallon per hour.
In my correspondence with a GAMI rep, the suggestion was a take off fuel flow of 32 GPH when using 10:1 pistons.
What are you IO-550 operators getting for take off fuel flow?? What recommendations have you heard or seen?
Lancair IV, IO-550, awaiting a new Hartzell prop