From: "Marvin Kaye" <marv@lancaironline.net>
Subject: Re: [LML] Re: Engine Cooling
To: lml
Date: Tue, 31 Aug 2004 11:52:05 -0400
Message-ID: <web-386716@logan.com>
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Posted for Walter Atkinson <walter@advancedpilot.com>:

  Gary:
  
  You are right.  It is important to remember that the majority  of the air
  going INTO most cowls goes right back out of the FRONT of the cowl, toward
  the prop!  Kinda puts "leaks" in perspective, doesn't it ! ? ! <g>
  
  Cooling effectiveness is enhanced by WHERE the air goes.  Cooling drag is
  affected, among other things, by how much of the air moves freely through
  the system and out along the path we want it to take going out!
  
  In a perfect cowl, I'd like no more air coming in than I need for cooling
  and have it all go exactly where I want it to go and OUT where I want it to
  go out.
  
  That sure is easy to say but difficult to accomplish.
  
  Walter
  

> I believe being able to maintain maximum
> pressure above the engine will allow a higher pressure below the engine and
> hence more velocity recovery.  The balance between the two is all about
> compromise.  I agree that if other things are done well a significant leak
> won't effect cooling effectiveness, but it must have an effect on cooling
> drag as "wasted" air is going through the engine compartment instead of
> around it.  Again, excellent comments.