Return-Path: Received: from fed1rmmtao04.cox.net ([68.230.241.35] verified) by logan.com (CommuniGate Pro SMTP 4.2b8) with ESMTP id 335407 for flyrotary@lancaironline.net; Tue, 27 Jul 2004 01:50:56 -0400 Received-SPF: error receiver=logan.com; client-ip=68.230.241.35; envelope-from=daveleonard@cox.net Received: from davidandanne ([68.111.224.107]) by fed1rmmtao04.cox.net (InterMail vM.6.01.03.02.01 201-2131-111-104-103-20040709) with SMTP id <20040727055025.XFTQ21079.fed1rmmtao04.cox.net@davidandanne> for ; Tue, 27 Jul 2004 01:50:25 -0400 From: "DaveLeonard" To: "Rotary motors in aircraft" Subject: Prop Speeds Date: Mon, 26 Jul 2004 22:50:30 -0700 Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0072_01C47362.F36183E0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1441 Importance: Normal In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_0072_01C47362.F36183E0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit MessageWow, that is 2935 RPM at the prop with a prop tip speed of just under 900 FPS. I am still too shy to run mine that fast, although I could easily get there. Interestingly, the calculations say the max corkscrew speed of that prop at that RPM is only 197mph. He could pick up a little for being really clean, and maybe some more depending on how they calculate prop pitch. That makes sense because according to the program I have your max speed should be 180 mph at 5800 RPM. So you and Tracy seem to be easily exceeding what my program predicts while it seems to be right on for me. (194 mph at 6000 rpm with my 68x74 prop). That would give me 205mph at 6350rpm... still not fast enough to beat you c-drive guys. Perhaps the fact that I have an RV6 is slowing me down, or maybe my prop is not really 74" (or even 71"). Regardless, its time to get a bigger prop. :-) Dave Leonard BTW, does anyone know how fast Tracy let his old prop turn? What size is it? Rusty? Hi Dave, According to Performance Props, Tracy's first prop was finalized at 68" D x 71" P. According to Tracy, the max he turned was 6350 at 215 MPH. I haven't made any full speed runs, but have turned it 5800 rpm at 8000 ft, and 196 mph TAS. Rusty ------=_NextPart_000_0072_01C47362.F36183E0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
Wow, = that is 2935=20 RPM at the prop with a prop tip speed of just under 900 FPS.  I am = still=20 too shy to run mine that fast, although I could easily get there. =20 Interestingly, the calculations say the max corkscrew speed of that prop = at that=20 RPM is only 197mph.  He could pick up a little for being really = clean, and=20 maybe some more depending on how they calculate prop = pitch.
 
That = makes sense=20 because according to the program I have your max speed should be 180 mph = at 5800=20 RPM.  So you and Tracy seem to be easily exceeding what my program = predicts=20 while it seems to be right on for me.  (194 mph at 6000 rpm with my = 68x74=20 prop).  That would give me 205mph at 6350rpm... still not fast = enough=20 to beat you c-drive guys.  Perhaps the fact that I have an RV6 is = slowing=20 me down, or maybe my prop is not really 74" (or even 71"). =20
 
Regardless, its=20 time to get a bigger prop.  :-)
 
Dave=20 Leonard
BTW, = does anyone=20 know how fast Tracy let his old prop turn?  What size is = it? =20 Rusty?
 
Hi Dave,
 
According to=20 Performance Props, Tracy's first prop was finalized at 68" D x = 71"=20 P.  According to Tracy, the max he turned was 6350 at 215 = MPH.  I=20 haven't made any full speed runs, but have turned it 5800 rpm at 8000 = ft, and=20 196 mph TAS.  
 
Rusty
 
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