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
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Fred Moreno
Sent: Sunday, October 12, 2008
7:49 PM
To: lml@lancaironline.net
Subject: [LML] IO-550N take off
fuel flow
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