Return-Path: Received: from [24.25.9.100] (HELO ms-smtp-01-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 2945468 for flyrotary@lancaironline.net; Fri, 23 Jan 2004 08:40:41 -0500 Received: from edward (clt78-020.carolina.rr.com [24.93.78.20]) by ms-smtp-01-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id i0NDecKZ028763 for ; Fri, 23 Jan 2004 08:40:39 -0500 (EST) Message-ID: <009c01c3e1b6$7d093a00$2402a8c0@edward> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] FW: [VAF Mailing List] Engine Choice Date: Fri, 23 Jan 2004 08:40:38 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0099_01C3E18C.93EBC8C0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1158 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0099_01C3E18C.93EBC8C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ed Anderson RV-6A N494BW Rotary Powered Matthews, NC ----- Original Message -----=20 From: Greg Fuess=20 To: Rotary motors in aircraft=20 Sent: Thursday, January 22, 2004 10:23 PM Subject: [FlyRotary] FW: [VAF Mailing List] Engine Choice Guys, =20 Forgive me for beating a dead horse about torsionals. I have been = reading another list for (VAF and RV-7) ~2 years, and have anxiously = anticipated installing a 13B, and now instead a Renesis engine, in my = soon-to-start RV-7. Now, I am hearing things that cause me to question = my ability to make a sound decision in this regard, as this is the first = discussion of torsionals is the first I have heard. I am beginning to = question my ability to follow through on what I had taken to be the best = alternative engine choice. =20 I am therefore forwarding the most seemingly competent post (I am not = enough of an engineer to evaluate this) regarding this issue. My first = impressions were that rotaries were much less susceptible to torisionals = that regular engines, but recently that view has come into apparently = serious question, based on the statements below. =20 Appreciate your thoughts and comments. =20 Regards, =20 Greg Fuess =20 Greg, I believe the best evidence that Bill's viewpoint is somewhat = misleading is that there are very few powersport PSRUs flying - while = between the old Ross RSRU and Tracy's series of Redrives there has to be = at least 30 airfames flying. Tracy has over 1400 hours, many others are = in the hundreds of hours and one gyrocopter (Using a Ross Planetary PSRU = reported had accumulated over 2500 hours) with not a single reported = case (to my knowledge) of PSRU failure caused by torsional problems. My = point is that if there were a problem with torsionals and the planetary = gear box approach to PSRUs for the rotary it would have surfaced long = before now. I think someone pointed out that there is a difference in the load = profile between a dyno and a propeller - perhaps that could be the = reason these "Failures" only seem to happen on Dynos. =20 However, having said that - YOU are the one that has to make the = decision. You are doing the right thing in getting different viewpoints = - but, viewpoints and opinions are cheap. Evidence of what is working = in aircraft, I believe is what you should look for. The PowerSport PSRU = will apparently work, even if a big heavy and pricey, and we know that = Tracy's redives work with numerous flying examples. But, you need to = consider your comfort level with each. =20 Good luck Ed Anderson ------=_NextPart_000_0099_01C3E18C.93EBC8C0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
----- Original Message -----
From:=20 Greg=20 Fuess
Sent: Thursday, January 22, = 2004 10:23=20 PM
Subject: [FlyRotary] FW: [VAF = Mailing=20 List] Engine Choice

Guys,

 

Forgive me = for=20 beating a dead horse about torsionals.  I have been reading = another list=20 for (VAF and RV-7) ~2 years, and have anxiously anticipated installing = a 13B,=20 and now instead a Renesis engine, in my soon-to-start RV-7.  Now, = I am=20 hearing things that cause me to question my ability to make a sound = decision=20 in this regard, as this is the first discussion of torsionals is the = first I=20 have heard.  I am beginning to question my ability to follow = through on=20 what I had taken to be the best alternative engine=20 choice.

 

I am = therefore=20 forwarding the most seemingly competent post (I am not enough of an = engineer=20 to evaluate this) regarding this issue.  My first impressions = were that=20 rotaries were much less susceptible to torisionals that regular = engines, but=20 recently that view has come into apparently serious question, based on = the=20 statements below.

 

Appreciate = your=20 thoughts and comments.

 

Regards,

 

Greg=20 Fuess

 

 

Greg, I believe the = best evidence=20 that Bill's viewpoint is somewhat misleading is that there are = very few=20 powersport PSRUs flying - while between the old Ross RSRU and = Tracy's=20 series of Redrives there has to be at least 30 airfames flying.  = Tracy=20 has over 1400 hours, many others are in the hundreds of hours and one=20 gyrocopter (Using a Ross Planetary PSRU reported had accumulated over = 2500=20 hours) with not a single reported case (to my knowledge) of PSRU = failure=20 caused by torsional problems.  My point is that if there were a = problem=20 with torsionals and the planetary gear box approach to PSRUs for the=20 rotary it would have surfaced long = before now.

 

I think someone = pointed out that=20 there is a difference in the load profile between a dyno and a = propeller -=20 perhaps that could be the reason these "Failures" only seem to happen = on=20 Dynos. 

 

However, having said = that - YOU are=20 the one that has to make the decision.  You are doing the right = thing in=20 getting different viewpoints - but, viewpoints and opinions are = cheap. =20 Evidence of what is working in aircraft, I believe is what you should = look=20 for.  The PowerSport PSRU will apparently work, even if a big = heavy and=20 pricey, and we know that Tracy's redives work with numerous flying=20 examples.  But, you need to consider your comfort level with=20 each.  

 

Good luck

 

Ed=20 Anderson

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