X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.123] verified) by logan.com (CommuniGate Pro SMTP 5.3.9) with ESMTP id 4493079 for flyrotary@lancaironline.net; Mon, 04 Oct 2010 19:20:31 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.123; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=1.1 cv=R3xZCyK5Rzzq4RgmEA8QIQ3hFZTdsD3z+kRPUs1QTwQ= c=1 sm=0 a=nAj-9e3w_JcA:10 a=rPkcCx1H5rrOSfN0dPC7kw==:17 a=Ia-xEzejAAAA:8 a=arxwEM4EAAAA:8 a=r1ClD_H3AAAA:8 a=ONuiK7t0NnaOlxdSoxIA:9 a=TYSdh0lEKKa9y6Zbrv4A:7 a=sFsZPtf8Np26edd_MFA3mAxb5icA:4 a=wPNLvfGTeEIA:10 a=EzXvWhQp4_cA:10 a=Ayl-FlaE7YIpN17o:21 a=sLym5WMjgewJEBwT:21 a=yMhMjlubAAAA:8 a=1oqGTYSLAAAA:8 a=9-7Ynzz6E8Sj8t4NGckA:9 a=RtGWy2begKXB4WjQv_wA:7 a=ObjB4X_8Wzg91u4bx37jC2cwx6YA:4 a=cvn8laQl214A:10 a=rPkcCx1H5rrOSfN0dPC7kw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.167.5 Received: from [174.110.167.5] ([174.110.167.5:49597] helo=EdPC) by cdptpa-oedge01.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id 8D/0F-06710-9116AAC4; Mon, 04 Oct 2010 23:19:54 +0000 Message-ID: <4987E1EEC959487D9E1250F0B64DAACE@EdPC> From: "Ed Anderson" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: Sam Hodges Prop area Comparison Date: Mon, 4 Oct 2010 19:19:53 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0011_01CB63F9.1F942480" 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_0011_01CB63F9.1F942480 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Based on my own experience and many others, its not usually to have the = starting HP be a bit lower than what you end up with after sorting = things out. Always best to wait a bit before trimming the prop - I know = folks who have trimmed theirs and later wish they had not. But, if you have anywhere close to 8" of cord, then I'll bet a beer or = two you'll be sending it back - even with a turbo that prop would have = been hard to push past 6000 rpm static. Ed From: Chris and Terria=20 Sent: Monday, October 04, 2010 5:58 PM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: Sam Hodges Prop area Comparison Ed, =20 I will measure next time I am at the airport. But I know I will be = closer to Sam's numbers. My prop looks exactly like his. =20 This makes me feel a little better, as I was wondering why my static was = so low compared to other's numbers. =20 I still think I will get airborne again, and actually check out what my = dynamic max RPM is before I make any changes. =20 Chris =20 From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On = Behalf Of Ed Anderson Sent: Monday, October 04, 2010 6:58 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Sam Hodges Prop area Comparison =20 Hi Chris, =20 With Sam's original prop, he got around 5000 rpm max static. May have = been as high as 5100 but ranged around 4800-5000 rpm. When He put my = 74x88 Performance Prop on he got as high as 6100 rpm one time but each = time got at least 6000 rpm. =20 Measure your chord at its widest point - mine is 5 1/2", Sam's was = around 8" - not the whole story on a prop, but can be an indication of = whether your prop is close to one end of the spectrum or the other =20 Ed =20 From: Chris and Terria=20 Sent: Sunday, October 03, 2010 9:37 PM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: Sam Hodges Prop area Comparison =20 Ed, =20 I have the same Catto prop and mine is marked 76x88. I didn't get more = than 5000 RPM max static either. To be honest, I didn't look at the max = RPM while airborne, I was too busy looking at the temp, and I pulled the = power back as soon as I could. I hope to fly again with the new = radiator in a few weeks, and should be able to get new data. What were = Sam's numbers Max static with the CATTO and with your prop? =20 Thanks, =20 Chris =20 From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On = Behalf Of Ed Anderson Sent: Sunday, October 03, 2010 10:46 AM To: Rotary motors in aircraft Subject: [FlyRotary] Sam Hodges Prop area Comparison =20 Just doing a rough back of the envelope calculation comparing Sam = Hodges prop (8" cord) to my prop (5 1/2" cord) and assuming the two = props blade profiles were similar, Sam's prop would have approx 45% more = prop area trying to push the air back than my prop. Small wonder his = engine was groaning trying to spin it up to 6000 rpm. =20 Ed =20 Edward L. Anderson Anderson Electronic Enterprises LLC 305 Reefton Road Weddington, NC 28104 http://www.andersonee.com http://www.eicommander.com ------=_NextPart_000_0011_01CB63F9.1F942480 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Based on my own experience and many others, its = not=20 usually to have the starting HP be a bit lower than what you end up with = after=20 sorting things out.  Always best to wait a bit before trimming the = prop - I=20 know folks who have trimmed theirs and later wish they had = not.
 
But, if you have anywhere close to 8" of cord, = then I'll=20 bet a beer or two you'll be sending it back - even with a turbo that = prop would=20 have been hard to push past 6000 rpm static.
 
Ed

Sent: Monday, October 04, 2010 5:58 PM
Subject: [FlyRotary] Re: Sam Hodges Prop area=20 Comparison

Ed,

 

I=20 will measure next time I am at the airport.  But I know I will be = closer to=20 Sam=92s numbers.  My prop looks exactly like = his.

 

This=20 makes me feel a little better, as I was wondering why my static was so = low=20 compared to other=92s numbers.

 

I=20 still think I will get airborne again, and actually check out what my = dynamic=20 max RPM is before I make any changes.

 

Chris

 

From: Rotary = motors in=20 aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Ed=20 Anderson
Sent: Monday, October 04, 2010 6:58 AM
To: = Rotary=20 motors in aircraft
Subject: [FlyRotary] Re: Sam Hodges Prop = area=20 Comparison

 

Hi=20 Chris,

 

With Sam's=20 original prop, he got around 5000 rpm max static.  May have been as = high as=20 5100 but ranged around 4800-5000 rpm.  When He put my 74x88 = Performance=20 Prop on he got as high as 6100 rpm one time but each time got at least = 6000=20 rpm.

 

Measure your=20 chord at its widest point - mine is 5 1/2", Sam's was around 8" - not = the whole=20 story on a prop, but can be an indication of whether your prop is close = to one=20 end of the spectrum or the other

 

Ed

 

From: Chris and Terria=20

Sent: Sunday, = October 03,=20 2010 9:37 PM

To: Rotary motors in = aircraft=20

Subject: = [FlyRotary] Re: Sam=20 Hodges Prop area Comparison

 

Ed,

 

I=20 have the same Catto prop and mine is marked 76x88.  I didn=92t get = more than=20 5000 RPM max static either.  To be honest, I didn=92t look at the = max RPM=20 while airborne, I was too busy looking at the temp, and I pulled the = power back=20 as soon as I could.  I hope to fly again with the new radiator in a = few=20 weeks, and should be able to get new data.  What were Sam=92s = numbers Max=20 static with the CATTO and with your prop?

 

Thanks,

 

Chris

 

From: Rotary = motors in=20 aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Ed=20 Anderson
Sent: Sunday, October 03, 2010 10:46 AM
To: = Rotary=20 motors in aircraft
Subject: [FlyRotary] Sam Hodges Prop area=20 Comparison

 

Just doing a=20 rough back of the envelope calculation comparing  Sam Hodges prop = (8" cord)=20 to my prop (5 1/2" cord) and assuming the two props blade profiles were = similar,=20 Sam's prop would have approx 45% more prop area trying to push the air = back than=20 my prop.  Small wonder his engine was groaning trying to spin it up = to 6000=20 rpm.

 

Ed

 

Edward L.=20 Anderson
Anderson Electronic Enterprises LLC
305 Reefton=20 Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com=

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