Message-ID: <408B34E1.5060201@nc.rr.com>
Date: Sat, 24 Apr 2004 23:47:45 -0400
From: Ernest Christley <echristley@nc.rr.com>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: 2.85 redrive
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Marvin Kaye wrote:
> All this talk about 2.85 gear boxes, getting higher into the power 
> curve, improving cliumb performance, etc, is really interesting.  Since 
> 3 of my 6 initial reasons for going rotary were reliability, I'm 
> wondering what running at these higher power levels is going to do in 
> that regard.  I'm pretty convinced that running at 5300-5500 rpms at 
> cruise is a good formula for having an engine that isn't overtaxed and 
> Tracy's experience has borne this out.  Isn't there any concern out 
> there about increased wear to the rotor housings, greater potential for 
> catastrophic failure and so on, at these considerably higher constant 
> power levels?  I hate to be a wet blanket, but what are the real 
> longterm tradeoffs in operating routinely at 15-20% higher power levels?
> 
>    <Marv>
>  
> 
>>>  Homepage:  http://www.flyrotary.com/
>>>  Archive:   http://lancaironline.net/lists/flyrotary/List.html
> 
> 

The racing guys have told us that the rotary holds up well at the higher 
RPMs, but it is true that a rotor housing only has so many revolutions 
in it, so it does wear out faster.  Run it at higher RPM, it doesn't 
last as long.  The way I rationalize it is that I'll probably put in 
about 100hrs a year.  Rebuilding at 1000hrs will give me a decade of 
flight.  In a decade the 200 pound RX-12 engine will give me 400hp in a 
package that I can carry in a briefcase. I'll worry about designing a 
new engine mount then.

Some things bother me less than others 8*)

-- 
http://www.ernest.isa-geek.org/
"Ignorance is mankinds normal state,
   alleviated by information and experience."
                                   Veeduber