X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.122] verified) by logan.com (CommuniGate Pro SMTP 5.4.1) with ESMTP id 5113512 for flyrotary@lancaironline.net; Sun, 04 Sep 2011 11:40:21 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.122; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=1.1 cv=4MSDN839FDsgJpwQlr+eLEnlTy8eaQTddc4+Fk+GTfI= c=1 sm=0 a=lAx3a_lreMQA:10 a=SC71y0a/4S6V9vjVxUojGA==:17 a=pedpZTtsAAAA:8 a=HZJGGiqLAAAA:8 a=pGLkceISAAAA:8 a=Ia-xEzejAAAA:8 a=UKPAHat8AAAA:8 a=3oc9M9_CAAAA:8 a=K97f1LLK5bCMTyQPNaYA:9 a=YCvNKTR6XBQ4Tl-hsDcA:7 a=wPNLvfGTeEIA:10 a=eJojReuL3h0A:10 a=HeoGohOdMD0A:10 a=MSl-tDqOz04A:10 a=EzXvWhQp4_cA:10 a=7god_763jbgA:10 a=U8Ie8EnqySEA:10 a=GWYyUk5kCCGivuvlFp4A:9 a=_BGVLLQKpm8xD62CxqMA:7 a=tXsnliwV7b4A:10 a=SC71y0a/4S6V9vjVxUojGA==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.175.135 Received: from [174.110.175.135] ([174.110.175.135:49871] helo=EdPC) by cdptpa-oedge03.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id A9/23-28959-2CB936E4; Sun, 04 Sep 2011 15:39:46 +0000 Message-ID: From: "Ed Anderson" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Tip speed was : [FlyRotary] Re: 20B Tuning Date: Sun, 4 Sep 2011 11:39:33 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0007_01CC6AF7.50F2D660" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 This is a multi-part message in MIME format. ------=_NextPart_000_0007_01CC6AF7.50F2D660 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable According to an on-line prop tip speed calculator at 70F, you can spin = the 76 " dia prop at 2550 rpm and have a tip speed of around mach 0.75 = which still keeps it a bit on the low side of the desirable range for = tip speed (0.88 - 0.92Mach). However, there could be other reasons for = the restriction as has been mentionded such as structure limits, tip = flutter, prop track disc, etc. Ed From: coastiefamily4=20 Sent: Sunday, September 04, 2011 11:24 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: 20B Tuning I think there must be a typo in the manual, I rechecked it this morning = and is reads 2150RPM. Instead of 2150 RPMs on the prop I am thinking it = should be 2550RPMs for a 76inch prop for a tip speed limit of 850fps = equating to 7250 engine RPMs. I will call the manufacture on Tuesday to = verify my calculations. =20 I appreciate everyone's comments. On Sun, Sep 4, 2011 at 8:07 AM, Charlie England = wrote: Wow. How big is it?=20 On 09/03/2011 10:50 PM, coastiefamily4 wrote:=20 Tip speed On Sat, Sep 3, 2011 at 9:18 PM, Kelly Troyer wrote: Is the rpm limit because of diameter (tip speed) or a structural = blade limitation ?.............. Kelly Troyer "DYKE DELTA JD2" (Eventually) "13B ROTARY"_ Engine "RWS"_RD1C/EC2/EM2 "MISTRAL"_Backplate/Oil Manifold "TURBONETICS"_TO4E50 Turbo From: coastiefamily4 To: Rotary motors in aircraft Sent: Saturday, September 3, 2011 6:06 PM Subject: [FlyRotary] Re: 20B Tuning The prop is adjustable, it is hydraulically controlled. I current = have it set to the fine pitch setting. On Sat, Sep 3, 2011 at 4:51 PM, Bobby J. Hughes = wrote: If it's adjustable you may need more pitch. A 2150 rpm limit = seem very low. Bobby Sent from my iPad On Sep 3, 2011, at 5:57 PM, "coastiefamily4" = wrote: This is not full throttle, I have to stop at 6000 RPMs do to = the 2150 RPM limit on my prop. I am using a VARI PROP, it is great so = far. I have plenty of throttle, just prop limited.=20 On Sat, Sep 3, 2011 at 3:44 PM, William Wilson = wrote: 23.3 is just about exactly what would be expected. Perhaps the throttle is not opening all the way? You would = have to have a pretty convoluted intake to lose 3" of pressure in it.=20 On Sat, Sep 3, 2011 at 3:40 PM, wrote: At what density altitude was that measured? Maybe your MAP = needs to be calibrated. Brian Trubee -----Original Message----- From: coastiefamily4 To: Rotary motors in aircraft = Sent: Sat, Sep 3, 2011 1:50 pm Subject: [FlyRotary] 20B Tuning My static MAP before starting the engine was 23.3=20 ------=_NextPart_000_0007_01CC6AF7.50F2D660 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
According to an on-line prop tip speed = calculator at 70F,=20 you can spin the 76 " dia prop at 2550 rpm and have a tip speed of = around mach=20 0.75 which still keeps it a bit on the low side of the desirable range = for tip=20 speed (0.88 - 0.92Mach).  However, there could be other reasons for = the=20 restriction as has been mentionded such as structure limits, tip = flutter, prop=20 track disc, etc.
 
Ed

Sent: Sunday, September 04, 2011 11:24 AM
Subject: [FlyRotary] Re: 20B Tuning

I think there must be a typo in the manual, I rechecked = it this=20 morning and is reads 2150RPM.  Instead of 2150 RPMs on the prop I = am=20 thinking it should be 2550RPMs for a 76inch prop for a tip speed limit = of 850fps=20 equating to 7250 engine RPMs.  I will call the manufacture on = Tuesday to=20 verify my calculations. 

I appreciate everyone's = comments.

On Sun, Sep 4, 2011 at 8:07 AM, Charlie England = <ceengland@bellsouth.net>=20 wrote:
Wow. How big is it?=20


On 09/03/2011 10:50 PM, coastiefamily4 wrote:=20
Tip speed

On Sat, Sep 3, 2011 at 9:18 PM, Kelly = Troyer <keltro@att.net> wrote:
Is the rpm limit because of diameter (tip speed) or a=20 structural blade limitation = ?..............
 
Kelly Troyer
"DYKE DELTA JD2" = (Eventually)
"13B ROTARY"_ = Engine
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil=20 Manifold
"TURBONETICS"_TO4E50 Turbo

From:=20 coastiefamily4 <coastiefamily4@gmail.com>
To: Rotary motors in = aircraft <flyrotary@lancaironline.net>
Sent: Saturday, September = 3, 2011=20 6:06 PM
Subject:=20 [FlyRotary] Re: 20B Tuning

The prop is adjustable, it is hydraulically controlled.  = I=20 current have it set to the fine pitch setting.

On Sat, Sep 3, 2011 at 4:51 PM, Bobby J. Hughes <bhughes@qnsi.net> wrote:
If it's adjustable you may need more pitch. A 2150 rpm = limit seem=20 very low.    Bobby


Sent from my iPad

On Sep 3, 2011, at 5:57 PM, "coastiefamily4" <coastiefamily4@gmail.com> = wrote:

This is not full throttle, I have to stop at 6000 RPMs do = to the=20 2150 RPM limit on my prop. I am using a VARI PROP, it is great = so=20 far.   I have plenty of throttle, just prop limited. =

On Sat, Sep 3, 2011 at 3:44 PM, William Wilson <fluffysheap@gmail.com> = wrote:
23.3=20 is just about exactly what would be expected.

Perhaps = the=20 throttle is not opening all the way?  You would have to = have a=20 pretty convoluted intake to lose 3" of pressure in it.=20


On Sat, Sep 3, 2011 at 3:40 PM, <bktrub@aol.com> wrote:
At what density altitude was that measured? Maybe = your MAP=20 needs to be calibrated.
 
Brian Trubee



-----Original=20 Message-----
From: coastiefamily4 <coastiefamily4@gmail.com>
To: = Rotary=20 motors in aircraft <flyrotary@lancaironline.net>
Sent: Sat,=20 Sep 3, 2011 1:50 pm
Subject: [FlyRotary] 20B = Tuning

My static MAP before starting the engine was 23.3=20 =








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