View Single Post
  #19  
Unread 08-08-02, 09:08 PM
kevin kevin is offline
Registered User
 
Join Date: Apr 2002
Location: Hillsboro, OR (HIO)
Posts: 843
kevin is on a distinguished road
On the "not full power takeoff" thing, I just don't agree. I run 35" and 2800 (full) RPM, (35" because of the intercoolers) during takeoff, then back off to 31 and 2500 for climb. I have read and heard many fine arguements on why full power takeoffs are best, and never heard a decent argument for why not, except a vague "your pushing the engine too hard". I've been running the engines this way for seven years, but in the end, like most things in general aviation, who really knows. Maybe I am just lucky. I am sure some more knowledgable folks will chime in with opinions in both directions...

Oh, and I guess the rear turbo did come apart on me on an 800 hour engine, therefore proving that full power takeoffs are bad (although it came apart in cruise). On the other hand, my front engine had over 1650 hours on in and was still working great when I replaced it, therefore proving that full power takeoffs are good...

Most of my takeoffs are at gross weight, or very close.

To 17,000, I use 27"/2400 RPM. FL180 and above, I use 27" and 2450 RPM to keep pressurization going. I flight plan 10 ga for climb and then 25 GPH. I use less than that, but have only Cessna's fuel flow (really fuel pressure) gauge, which I do not trust. I suspect I am burning between 23 and 24 GPH.

I don't agree with leaning in climb. Leaning will reduce your margin against detonation, and saves so little fuel as to not be noticeable. I know the book says to do it, but at the power setting I described, my full rich fuel flow is about 110 pph, not far off of what the book suggests. In climb, I think richer is better. Again, what I have read and learned from others supports this, but I did not make a point of retaining the sources.

Kevin
Reply With Quote