View Single Post
  #10  
Unread 01-18-12, 08:46 PM
Walter Atkinson Walter Atkinson is offline
Registered User
 
Join Date: Mar 2005
Location: Vail, Colorado
Posts: 95
Walter Atkinson is an unknown quantity at this point
Quote:
Originally Posted by Ernie Martin View Post
I go to 25/25 at about 500 ft and leave the throttle there until the descent, so at cruise MF may be as low as 19; I normally lower RPM to 23 or 24 when I get to cruise altitude.
Ernie:

After TESTING various methods in both an advanced engine test facility and on a very well-instrumented airplane (read pressure transducers, etc) you may be surprised to discover that the easiest one can be on the NA engine is to leave the throttle wide open and the prop full forward until reaching cruise altitude and then setting whatever cruise setting you choose.

1) The internal cylinder pressures at WOT/max RPM are lower than at 25/2500. CHTs will be better controlled.

2) Lean to the Target EGT as you climb.

That gets one to altitude quicker, saves fuel and is much easier on the engine. Based on the hard data, the notion that reduced throttle settings during a climb are "babying" an engine are misplaced.
__________________
Walter Atkinson
Advanced Pilot Seminars
Reply With Quote