Mailing List flyrotary@lancaironline.net Message #37287
From: Jarrett & Heidi Johnson <hjjohnson@sasktel.net>
Subject: Re: [FlyRotary] Re: Marginal Cooling
Date: Tue, 22 May 2007 19:58:10 -0600
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
I have no horse in this race at this time, however something that Thomas wrote struck me funny.  If this is the standard to which we should be building our a/c then the Certified C414A that I fly in [one of my day job's] wouldn't fit it in two area's.
A) I had a 1hr 47min  idle on the ground in KLAS [waiting to be #1 for dept] here a few weeks ago, I finally had to ask the tower to let me turn into the wind as my oil temp's were getting too high.
C) If I was to climb out at just over Vmca I KNOW that the cylinders would hit over redline in under the five minutes. I don't know why someone would do this as Vx and Vy are both up around 100-120knts [Vmca=79knt] but you did say ANY speed... Anyway, just another data point to hold up to the light and compare w/ what you guys see as a need and a want..
 
Jarrett

Personally I believe that a cooling system should be able to:
 
a) Run indefinite on the ground - like long waiting cues on taxi ways, any wind direction
b) Support a min 1 min full power run-up
c) Support a min 5 min Max Power climbout at any possible speed (slower being the worst....)
 
I'd rather play with movable cowl-flaps, etc. than accepting that I might not be able to pull full power at any point.
 
What if you are already maxed out, because OAT is high, you are heavy, in a nasty turbulence and have to do an "emergency" climb out.
You have an engine, that could do it easily, ....if you had a system that would cool it.
 
Plan starts with rereading all cooling posts, get the calculator, get familiar with heat transfer tables, plan on spending some serious money for custom coolers....
 
Plan is to built for the worst case. I always can reduce cooling....
 
Thomas
 
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