Return-Path: <13brv3@bellsouth.net> Received: from imf23aec.mail.bellsouth.net ([205.152.59.71] verified) by logan.com (CommuniGate Pro SMTP 4.2b8) with ESMTP id 329226 for flyrotary@lancaironline.net; Wed, 21 Jul 2004 14:19:36 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.71; envelope-from=13brv3@bellsouth.net Received: from rd ([65.6.194.9]) by imf23aec.mail.bellsouth.net (InterMail vM.5.01.06.08 201-253-122-130-108-20031117) with ESMTP id <20040721181906.FCMC1779.imf23aec.mail.bellsouth.net@rd> for ; Wed, 21 Jul 2004 14:19:06 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Tracy Report Date: Wed, 21 Jul 2004 13:19:18 -0500 Message-ID: <000001c46f4f$3cc88410$6101a8c0@rd> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C46F25.53F27C10" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C46F25.53F27C10 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Since Tracy and I had the same static rpm with the previous props (which were the same made by Performance Prop), I expect I would have the same static he is getting if I had the 74" which I believe he indicated was around 6200 rpm or about 1000 rpm higher than with the old 2.14 and 68x72" prop. That 1000 rpm increase will translate into approx 30HP more for take off and move the torque from 345 lb-ft to 455 lb-ft or a gain of approx 110 lb-ft torque for take off. According to my spreadsheet that would move the take off HP from around 155 up to 185 for a standard day - in the cooler weather of all, it will be even more impressive. Talking to Tracy about the difference between his B and C setups got me all excited again. Sounds like he was REALLY happy with the performance difference. There's a fairly simple formula I saw once that converts excess HP to climb rate, given the weight of the plane. Do you have that? It would be interesting to see what 30 extra HP would do. Cheers, Rusty (I need a runway) ------=_NextPart_000_0001_01C46F25.53F27C10 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
 Since Tracy and I had the same = static rpm=20 with the previous props (which were the same made by Performance Prop), = I expect=20 I would have the same static he is getting if I had the 74" which I = believe he=20 indicated was around 6200 rpm or about 1000 rpm higher than with the old = 2.14=20 and 68x72" prop.  That 1000 rpm increase will translate into approx = 30HP=20 more for take off and move the torque from 345 lb-ft to 455 lb-ft or a = gain of=20 approx 110 lb-ft torque for take off.  According to my spreadsheet = that=20 would move the take off HP from around 155 up to 185 for a standard day = - in the=20 cooler weather of all, it will be even more impressive.
 
 
Talking to=20 Tracy about the difference between his B and C setups got me all excited = again.  Sounds like he was REALLY happy with the performance=20 difference. 
 
There's a=20 fairly simple formula I saw once that converts excess HP to climb rate, = given=20 the weight of the plane.  Do you have that?  It would be = interesting=20 to see what 30 extra HP would do. 
 
Cheers,
Rusty (I need=20 a runway)
------=_NextPart_000_0001_01C46F25.53F27C10--