Message-ID: <405E66D0.5080300@netdoor.com>
Date: Sun, 21 Mar 2004 22:08:48 -0600
From: Charlie & Tupper England <cengland@netdoor.com>
Reply-To: cengland@netdoor.com
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Data?  Was : Renesis & RD-1C drive testing
References: <list-3111999@logan.com>
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Tracy Crook wrote:

> Hi Ed,
> Wish I had more carefully documented fuel burn vs airspeed on the -B 
> drive & old prop.  But from the few well documented points that I 
> have, it looks about the same at 6.0 GPH (sea level) IAS, 143 - 148 
> depending on OAT, humidity, etc (its amazing how much conditions 
> affect things).  This is the only point I've had a chance to compare 
> so far.  I have not built the prop blade cuffs that I feel will be 
> necessary to get best performance from this combination.  Clark at 
> Performance Props was very honest about the difficulty in getting the 
> proper pitch at the blade root (out to ~ 3" past the 13" dia. spinner) 
> with pitch this high.  This being the case, I'm very happy with the 
> results so far. 
>  
> Other conclusions are that anything less than 74" L prop is a waste on 
> the -C drive.  More would be better but that's as long as the -4 prop 
> clearance would allow. 
>  
> I can't measure static rpm (plane wants to skid on grass and/or nose 
> over) but climb RPM is at 6200 at 120 mph (up from about 5200 with -B 
> drive) and VSI is pegged (hard!).  Only did very brief test of WOT in 
> level flight and engine hit 7050 rpm.  IAS was still climbing at 215 
> mph.  Oil cooling has suffered due to stalled air around prop hub and 
> reversed spiral of airflow due to RH prop.  Erased several years of 
> tweaking inlet shapes.
>  
> Most unexpected finding so far is the radically improved glide at idle 
> setting.  Have no clue why.  Would have expected worse instead of better.
>  
> Tracy

Don't you have radically increased pitch in the prop? That will do it.

Charlie