Jack uses 29" and 16.5 because it gives him about 245 Hp and good range
with good speed and cool CHTs in cruise.  Nice compromise.

Could he use 32 or 33" x 2500 and 17.5 or maybe 18 gph?  Possibly.

It would depend on what happens to the CHTs.  

The "add back" is probably not necessary at 29",  but is probably
worthwhile when trying to use more than 30".

Regards,  


-----Original Message-----
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of
Marvin Kaye
Sent: Tuesday, June 20, 2006 10:07 PM
To: Lancair Mailing List
Subject: [LML] Re: TSIO 550 break-in

Posted for "cblitzer" <cblitzer@triad.rr.com>:

  George,
  I had the L-IV-P that had the GAMI Injectors installed at your shop in
mid-March of this year.
  1 - I have the 8:5:1 pistons;
  2 - WOT, full rich, 2700 TIT's right at or below 1300
  3 - Redline MP is set at 36.5"
  4 - timing 22d TDC
  82 hours on engine, and yes your right, Jack McAllister is a great
source on
this engine and has helped me tremendously as has John Deakin.
  Here are the numbers I  fly at, Jack gave them to me but I must admit,
I am
still confused why a higher MP setting is not used for cruise
  Take-off - 36.5 @ 2700 (full power)
  climb - 33" @ 2600 rpm
  cruise 29" 2500 RPM @ 16.5 GPH - It should be noted that while I do
not want
to speak for Jack, he actually reduces the MP setting for cruise to 27",
goes
50 degree LOP and then increases the MP back to 29"  John Deakin
described
this to me as the "add back" feature, told me not to worry about it.
  What I cannot answer, (hopefully you can George), is why not a higher
MP
setting for cruise?  Is it because the max MP setting for this engine is
36.5"
so 29" MP cruise is to 36.5  as 32" is to 38.5", Continental's max MP?
  Thanks
  Craig
  
  

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