From: "Marvin Kaye" <marv@lancaironline.net>
Subject: Re: [LML] On Boosting Engines, Stressing Crankshaft and TBO
To: lml
Date: Mon, 27 Jun 2005 15:24:30 -0400
Message-ID: <web-1023548@logan.com>
In-Reply-To: <5692da0826a7a7650106b5a9e1a0da21@advancedpilot.com>
References: <list-1023193@logan.com>
 <5692da0826a7a7650106b5a9e1a0da21@advancedpilot.com>
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Posted for Walter Atkinson <walter@advancedpilot.com>:

  Alain:
  
  I think you're on the right track.
  
  1)  FYI, the jury in the Lycoming case had two engineers and one pilot
serving.  It appears to have been an educated and thoughtful jury.
  
  2) If you have ever seen crankshaft torsionals on a running engine, you 
would
be very concerned about boosting the power without doing a run on a test stand
to MEASURE these effects.  They can be huge and they can be significantly
affected by things like RPM and peak power pulse.  A normal crankshaft
torsional value could easily be in the +/- 3000 pound range.  This large
plus-minus force reversal is realized as many as 7 or 8 thousand times per
minute.  Crankshafts live a difficult life.
  
  3)  There has been compelling evidence shown that the Lycoming crankshaft
problem is one of design, not manufacture.
  
  Walter