From: "Marvin Kaye" <marv@lancaironline.net>
Subject: Re: FW: [LML] Compression, boost, and detonation
To: lml
Date: Tue, 25 Apr 2006 09:17:06 -0400
Message-ID: <web-1080219@logan.com>
In-Reply-To: <01d401c66844$57044400$c211140a@fred>
References: <01d401c66844$57044400$c211140a@fred>
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Posted for "Frederick Moreno" <fredmoreno@optusnet.com.au>:

  George:
  
  
  
  I believe you.  We were definitely detonation challenged!
  
  
  
  I can only report what we recorded and I subsequently committed to
  memory, my note book being long gone.  There may be a brain fade
  problem, not unlikely given my advancing age.  :-(
  
  
  
  It was clear that about 30 gph (or whatever we were working toward) was
  not enough.  The engine was a Lycoming, not a Continental, but I'm not
  sure that makes a hill of beans difference.  I leave it to others to
  comment.
  
  
  
  I would ask Brent to chime in if he remembers differently, particularly
  details of temperature, manifold pressure, and compression ratio.
  
  
  
Forgetful Fred?
  
  
  
  -----Original Message-----
From: George Braly [mailto:gwbraly@gami.com]
  Sent: Tuesday, 25 April 2006 7:49 AM
  Subject: RE: [LML] Compression, boost, and detonation
  
  
  
Fred,
  
  
  
  That is a fascinating description of that flight.
  
  
  
  Based on having run a similar engine with 8.5:1  (TSIO-550) on a test
  stand with internal cylinder pressure transducers,  I would predict that
  it would be difficult to avoid detonation under your flight conditions
  and at 320 Hp at any fuel flow less than about 0.66 to 0.68 BSFC.  That
  is about  35 to 37 gph.
  
  
  
...snip...