----- Original Message -----
From: "Marvin Kaye" <marv@lancaironline.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Saturday, April 24, 2004 10:52 PM
Subject: [FlyRotary] Re: 2.85 redrive


> 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>
>
>

Marv, I don't think there is any question that there will be more wear at
6500 rpm than 5500 rpm.  However, I am convinced that even 6500 rpm is not
unduly stressing or wearing the engine.  The trouble is the engines are so
good that no one has worn one out in aircraft use.  For me if I get similar
performance that I observed during Tracy's take off at Shady Bend, the
increased comfort factor of quickly getting up and high on a high altitude
density day with a heavily loaded aircraft off a grass strip is well worth
it.

I don't foresee any catastrophic type failures from such rpms.  I think any
wear will manifest it self as a slowly lowering of compression and power or
perhaps smoke from worn oil rings giving you plenty of time to correct it
before it becomes serious.  Even it reduces the useful life of the engine to
1000 hours, that buys me plenty of flying time.

We will see

Ed
Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC