Return-Path: <13brv3@bellsouth.net> Received: from imf20aec.mail.bellsouth.net ([205.152.59.68] verified) by logan.com (CommuniGate Pro SMTP 4.2b1) with ESMTP id 3149863 for flyrotary@lancaironline.net; Tue, 06 Apr 2004 23:09:54 -0400 Received: from rad ([68.221.179.221]) by imf20aec.mail.bellsouth.net (InterMail vM.5.01.06.08 201-253-122-130-108-20031117) with ESMTP id <20040407030953.TTQS1709.imf20aec.mail.bellsouth.net@rad> for ; Tue, 6 Apr 2004 23:09:53 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "Flyrotary List" Subject: Help Rusty pick a prop Date: Tue, 6 Apr 2004 22:09:58 -0500 Message-ID: <032f01c41c4d$cefc0960$6001a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0330_01C41C23.E6260160" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_0330_01C41C23.E6260160 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable OK, since Tracy keeps whining about my prop, let's talk about this. =20 =20 First, for those who don't know, I have a 68", 3 blade Warp Drive prop. It's currently not tapered, but Warp can taper the blades to get better = top end, without sacrificing climb. They requested that I wait until I = could give them pitch, rpm, and speed numbers before they tapered the tips, = since they needed to make sure they didn't take off too much blade area. I = have not done this yet, since I have only started flying the non-turbo = (final) configuration. =20 Here are the facts: =20 - The plane is an RV-3. The "standard" prop length is 68", which gives = 7 inches of clearance in two point attitude. =20 - I have a 2.17 RD-1B drive, and I can't go to the 2.85 because of the = left thrust built into my mount (at my request). =20 - The 13B engine was build by Bruce T, with 9.7 rotors, and street = porting. It is capable of running strong to 7500, and I would like that to be my = top rpm at WOT at sea level. I am not afraid to run 7000 rpm continuous. =20 =20 - The plane is a toy, and performance is more important than economy. I would like to be able to run up to the 210 VNE easily, while maintaining spectacular climb performance. =20 - I prefer adjustable pitch props, even if only ground adjustable. =20 =20 - I'm not afraid to run an IVO prop. =20 The way I look at this, to get the power I want from this engine, I have = to run high rpms. The only way I can do that is to stay with the 68" prop length. Warp required me to run a 3 blade for the power I expected, so = a 2 blade was not an option. I didn't ask IVO about this, but they may = require a 3 blade also. I came so very close to getting an IVO, just so I could = use the in-flight adjustable prop. That may be the key to getting the best climb and cruise performance. Even now, I'm seriously thinking of = ordering one, and trying to do the "cuff" thing that Tracy is doing if top speed = is an issue. Funny thing is that some folks seem to have a problem with = this, and some don't. =20 =20 OK, there you go. You'll notice that I really don't want to use a fixed pitch wood prop, unless that's clearly the best choice. Any = recommendations will be very welcome. =20 =20 Cheers, Rusty (this is going to cost me) =20 =20 =20 ------=_NextPart_000_0330_01C41C23.E6260160 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
OK, since Tracy = keeps=20 whining about my prop, let's talk about = this.  
 
First, for = those who don't=20 know, I have a 68", 3 blade Warp Drive prop.  It's currently not = tapered,=20 but Warp can taper the blades to get better top end, without sacrificing = climb.  They requested that I wait until I could give them pitch, = rpm, and=20 speed numbers before they tapered the tips, since they needed to make = sure they=20 didn't take off too much blade area.  I have not done this yet, = since I=20 have only started flying the non-turbo (final)=20 configuration.
 
Here are the=20 facts:
 
- The plane is = an=20 RV-3.  The "standard" prop length is 68", which gives 7 inches of = clearance=20 in two point attitude.
 
- I have a 2.17 = RD-1B=20 drive, and I can't go to the 2.85 because of the left thrust built into = my mount=20 (at my request).
 
- The 13B = engine was build=20 by Bruce T, with 9.7 rotors, and street porting.  It is capable of = running=20 strong to 7500, and I would like that to be my top rpm at WOT at sea=20 level.  I am not afraid to run 7000 rpm continuous. =20
 
- The plane is = a toy, and=20 performance is more important than economy.  I would like to be = able to run=20 up to the 210 VNE easily, while maintaining spectacular climb=20 performance.
 
- I prefer = adjustable pitch=20 props, even if only ground adjustable. 
 
- I'm not = afraid to run an=20 IVO prop.
 
The way I look = at this, to=20 get the power I want from this engine, I have to run high rpms.  = The only=20 way I can do that is to stay with the 68" prop length.  Warp = required me to=20 run a 3 blade for the power I expected, so a 2 blade was not an = option.  I=20 didn't ask IVO about this, but they may require a 3 blade = also.  I=20 came so very close to getting an IVO, just so I could use the in-flight=20 adjustable prop.  That may be the key to getting the best climb and = cruise=20 performance.  Even now, I'm seriously thinking of ordering one, and = trying=20 to do the "cuff" thing that Tracy is doing if top speed is an = issue.  Funny=20 thing is that some folks seem to have a problem with this, and some=20 don't.  
 
OK, there you = go. =20 You'll notice that I really don't want to use a fixed pitch wood prop, = unless=20 that's clearly the best choice.  Any recommendations will be = very=20 welcome.  
 
Cheers,
Rusty (this is = going to=20 cost me) 
 
 
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