Received-SPF: none
 receiver=logan.com; client-ip=68.142.229.103; envelope-from=sladerj@sbcglobal.net
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws;
  s=s1024; d=sbcglobal.net;
  h=Received:X-YMail-OSG:Message-ID:Date:From:Reply-To:User-Agent:MIME-Version:To:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding;
  b=tjZXJTgy3M1GVi6VTdGnn0K8JuvU+Jr8a98+Y7Tk5SGlAD6MrLLm1Nzj/9tPw5PqO6nr7yElPa1KRg3vRLqwmi04Sty2PuH1ZQaqceK+lAQwdjp49PDdd3KOaQwxSh4Ad5XxJOTS7uBUfgYasiGfJhoWrXsLxSbevjikG0SQkv0=  ;
Message-ID: <4650947D.8060609@sbcglobal.net>
Date: Sun, 20 May 2007 14:33:33 -0400
From: John Slade <sladerj@sbcglobal.net>
Reply-To:  sladerj@sbcglobal.net
User-Agent: Thunderbird 1.5.0.10 (Windows/20070221)
MIME-Version: 1.0
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Marginal Cooling contributes to Crash.
References: <list-2055261@logan.com>
In-Reply-To: <list-2055261@logan.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: quoted-printable

>You guys could improve the test. Just throwing out the concept.
I don't doubt your sincerity, Al, and the objective is admirable, but I t=
hink it would be VERY hard to achieve any real science comparing differen=
t installations, even on the same aircraft type at the same place on the =
same day. There are just too many variables. Inlet duct size & shape, out=
let size, airflow through the cowl, position of the heat exchangers, augm=
entation system design, overall drag, engine model, accurate measurement =
of actual results... the list is endless. There would always be enough no=
ise in the data to render it meaningless, especially with plans built air=
planes like the Cozy.=20

I believe that the ONLY way for each individual to approach the optimum i=
s first to establish what it is and then for them, then approach it scien=
tifically by changing things one at a time measuring airflow, cooling and=
 drag effects accurately as they go. This will be a very tedious exercise=
 involving lots time consuming redesign and rework, and its what many her=
e have done over the years to get us newbies to the point we're at today.=
 The reality of putting one of these installations together from scratch =
is an exercise is that you read and learn, look carefully at what other f=
lyers have done, decide what you think is best of all you have seen and l=
earned, then assemble your own approximation of a solution to meet your o=
wn particular goals. There's enough information around these days that, w=
ith a bit of luck, your first shot will work well enough to fly without o=
verheating. Once you reach this point you can begin the exercise of impro=
ving the cooling / cooling drag equation by experiment. The holy grail is=
 getting something that works (ie meets your own design criteria) first t=
ime. It's EZ to err to the side of cooling drag and get something that co=
ols but wont go fast. Its a lot harder to hit the target of something tha=
t goes fast and still cools enough. Its all about experimentation and com=
promise, with a little luck thrown in.

John Slade