Return-Path: Received: from [65.54.169.128] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.2b1) with ESMTP id 3150879 for flyrotary@lancaironline.net; Wed, 07 Apr 2004 11:51:22 -0400 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Wed, 7 Apr 2004 08:51:22 -0700 Received: from 4.174.7.19 by bay3-dav98.adinternal.hotmail.com with DAV; Wed, 07 Apr 2004 15:51:21 +0000 X-Originating-IP: [4.174.7.19] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: : Percent Power, Throttle position, & RD-1Cperformance Date: Wed, 7 Apr 2004 11:51:19 -0400 MIME-Version: 1.0 X-Mailer: MSN Explorer 7.02.0011.2700 Content-Type: multipart/alternative; boundary="----=_NextPart_001_0006_01C41C96.A3DA4780" Message-ID: X-OriginalArrivalTime: 07 Apr 2004 15:51:22.0210 (UTC) FILETIME=[2CA9C420:01C41CB8] ------=_NextPart_001_0006_01C41C96.A3DA4780 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Altitude! Altitude! Must know altitude. =20 I can go 190 mph at SL or at 15,000. Fuel burn is about double at SL com= pared to 15K. Tracy =20 ----- Original Message ----- From: Charlie & Tupper England Sent: Tuesday, April 06, 2004 9:03 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: : Percent Power, Throttle position, & RD-1Cperfo= rmance OK, how about a 'real world' cruise power fuel burn? My 160hp fixed =20 pitch Lyc powered -4 burned ~9.2-9.5 gph of avgas at ~190-195 statute =20 mph. What are you burning down around 190 mph (allowing a little wiggle =20 room for 'work in progress' aerodynamics of your plane)? Tracy Crook wrote: > Took closer note of throttle position on todays flight. At 2000 ft the =20 > throttle was only about 1/3 open (position of throttle quadrant, but =20 > it closely mirrors butterfly position) at economy cruise setting which =20 > was 6.0 GPH. This is about 42% power, 82 HP according to the EM2 which =20 > is fairly close but not perfectly calibrated yet. The same power =20 > setting with the -B drive would bave been a bit further open. > I did a quick check of MAP at 1000 ft at full throttle and found I was =20 > not getting any drop at 150 MPH and had .5" boost at 220 MPH (ram air =20 > recovery I assume). I did not get around to checking it in slow climb =20 > which would more accurately compare to what you would see on a dyno. > Finally got some reasonably calm air to do performance comparisons of =20 > -C drive vs -B drive. Without the prop blade cuffs it looks like the =20 > break even point is at 203 MPH. Above that -C burned more fuel than =20 > the -B. After installation of the cuffs, the break even point was off =20 > the scale! i.e., above top speed with -B drive. I had a good data =20 > point on the -B drive while burning 17 GPH (209 mph during SUN 100 =20 > race). At the same speed, the C drive was burning 15.8 gph. This was =20 > better than I had hoped for. > Tracy > > Thanks, Tracy. I was hoping there would be someone out there > flying with the same TB diameters. > > Like most things, TB diameter is a tradeoff. My conclusion from > the dyno data is that 44mm per rotor (1 =C2=BE) is a bit small as t= he > MAP is dropping off over 5000 RPM. But if you want to idle at > 1500, and have a decent transition from there to 3000; 1 =C2=BE is > good. For a 2.85 to redrive, I=E2=80=99d want to increase that flow= area > by 30% or so =E2=80=93 to about 2=E2=80=9D dia for each rotor. > > My data may not be representative because of restricted flow to > the TB. The =E2=80=98airbox=E2=80=99 size is restricted by the cowl= , and may have > restricted the flow a bit. In hindsight, it would have been smart > (and easy) to make a run with the airbox off and see what > difference it made. > > Al > >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_001_0006_01C41C96.A3DA4780 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable
Altitude! = ; Altitude!  Must know altitude. 
 
I can go 190 mph at SL or at 15,000.  Fuel burn is about double at = SL compared to 15K.
 
Tracy
&= nbsp;
----- Original Message -----
From: Cha= rlie & Tupper England
Sent:<= /B> Tuesday, April 06, 2004 9:03 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: : Percent Power, Throttle position, &a= mp; RD-1Cperformance
 
OK, how about a 'real world' = cruise power fuel burn? My 160hp fixed
pitch Lyc powered -4 burned ~9= 2-9.5 gph of avgas at ~190-195 statute
mph. What are you burning dow= n around 190 mph (allowing a little wiggle
room for 'work in progress= ' aerodynamics of your plane)?

Tracy Crook wrote:

> Took= closer note of throttle position on todays flight. At 2000 ft the
&g= t; throttle was only about 1/3 open (position of throttle quadrant, but <= BR>> it closely mirrors butterfly position) at economy cruise setting = which
> was 6.0 GPH. This is about 42% power, 82 HP according to t= he EM2 which
> is fairly close but not perfectly calibrated yet. T= he same power
> setting with the -B drive would bave been a bit fu= rther open.
> I did a quick check of MAP at 1000 ft at full throttl= e and found I was
> not getting any drop at 150 MPH and had .5" bo= ost at 220 MPH (ram air
> recovery I assume). I did not get around= to checking it in slow climb
> which would more accurately compar= e to what you would see on a dyno.
> Finally got some reasonably ca= lm air to do performance comparisons of
> -C drive vs -B drive. Wi= thout the prop blade cuffs it looks like the
> break even point is= at 203 MPH. Above that -C burned more fuel than
> the -B. After i= nstallation of the cuffs, the break even point was off
> the scale= ! i.e., above top speed with -B drive. I had a good data
> point o= n the -B drive while burning 17 GPH (209 mph during SUN 100
> race= ). At the same speed, the C drive was burning 15.8 gph. This was
>= better than I had hoped for.
> Tracy
>
>  &n= bsp;  Thanks, Tracy. I was hoping there would be someone out there>     flying with the same TB diameters.
>=
>     Like most things, TB diameter is a trade= off. My conclusion from
>     the dyno data is = that 44mm per rotor (1 =C2=BE) is a bit small as the
>  &= nbsp;  MAP is dropping off over 5000 RPM. But if you want to idle at=
>     1500, and have a decent transition from = there to 3000; 1 =C2=BE is
>     good. For a 2.= 85 to redrive, I=E2=80=99d want to increase that flow area
> &= nbsp;   by 30% or so =E2=80=93 to about 2=E2=80=9D dia for each= rotor.
>
>     My data may not be repres= entative because of restricted flow to
>     th= e TB. The =E2=80=98airbox=E2=80=99 size is restricted by the cowl, and ma= y have
>     restricted the flow a bit. In hind= sight, it would have been smart
>     (and easy= ) to make a run with the airbox off and see what
>   = ;  difference it made.
>
>     Al>



>>  Homepage:  http://www.flyrotary.= com/
>>  Archive:   http://lancaironline.net/list= s/flyrotary/List.html
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