Return-Path: Received: from [65.54.169.143] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 3112923 for flyrotary@lancaironline.net; Mon, 22 Mar 2004 11:38:13 -0500 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Mon, 22 Mar 2004 08:38:13 -0800 Received: from 64.159.105.196 by bay3-dav113.adinternal.hotmail.com with DAV; Mon, 22 Mar 2004 16:38:13 +0000 X-Originating-IP: [64.159.105.196] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: C mounting on a B plate?? Renesis & RD-1Cdrivetesting Date: Mon, 22 Mar 2004 11:38:13 -0500 MIME-Version: 1.0 X-Mailer: MSN Explorer 7.02.0011.2700 Content-Type: multipart/alternative; boundary="----=_NextPart_001_0006_01C41002.28A99D40" Message-ID: X-OriginalArrivalTime: 22 Mar 2004 16:38:13.0362 (UTC) FILETIME=[11A18520:01C4102C] ------=_NextPart_001_0006_01C41002.28A99D40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable OK, OK, rub it in, but before you guys get carried away, consider the fol= lowing: The prop limitation was always my only reservation about using the higher= ratio. I must emphasize that in order for this to work, the prop must n= ot only be long but has to have a good profile as far down toward the roo= t as possible with the MUCH higher pitch. I worked with Clark at Perf. P= rops and emphasized this. It required a thicker than standard hub to get= close to what was needed. If you don't do these things, all you get is significantly higher rpm, l= ess performance, higher fuel burn and higher wear. Look at the numbers f= rom previous users of the 2.85 drive. =20 Did I mention the three spinners, various spinner bulkheads, prop bolts t= hat were now too short and other various things that went wrong during t= he effort to make this work right? Tracy Finn Lassen wrote: > Tracy Crook wrote: > >> The -C drive has very different internals but I will look at the =20 >> feasibility of reworking the -B housing to receive the -C guts. I =20 >> think it can be done. Yes, the -C bolts right up to the same =20 >> adapter plate. I think you are right about the 2.85 becoming the =20 >> preferred ratio, but only if you can handle the longer prop. > > > Sounds like Paul Lamar was right all along... > > I simply couldn't resist throwing that in here :) > > Finn > (cleaning out my inbox to make room for responses) > > That's what I thought too, but didn't have the guts to say it here. It may not help us pusher guys though, we can't handle large diameter =20 props, possible prop strike on rotation. -- =20 Perry Mick http://www.ductedfan.com ------=_NextPart_001_0006_01C41002.28A99D40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

OK, OK, ru= b it in, but before you guys get carried away, consider the following:

The prop limitation was always my only reservation about using the h= igher ratio. I must emphasize that in order for this to work, the p= rop must not only be long but has to have a good profile as far down towa= rd the root as possible with the MUCH higher pitch. I worked with C= lark at Perf. Props and emphasized this. It required a thicker than= standard hub to get close to what was needed.

If you don't do the= se things, all you get is significantly higher rpm, less performanc= e, higher fuel burn and higher wear. Look at the numbers from previ= ous users of the 2.85 drive.

Did I mention the three = spinners, various spinner bulkheads, prop bolts that were now too short a= nd other various things that went wrong during the effort = ;to make this work right?

Tracy

Finn Lassen wrote:

> Tr= acy Crook wrote:
>
>> The -C drive has very different inte= rnals but I will look at the
>> feasibility of reworking the -B= housing to receive the -C guts. I
>> think it can be don= e. Yes, the -C bolts right up to the same
>> adapte= r plate. I think you are right about the 2.85 becoming the
>= > preferred ratio, but only if you can handle the longer prop.
>=
>
> Sounds like Paul Lamar was right all along...
>> I simply couldn't resist throwing that in here :)
>
> F= inn
> (cleaning out my inbox to make room for responses)
>>
That's what I thought too, but didn't have the guts to say it he= re.

It may not help us pusher guys though, we can't handle large d= iameter
props, possible prop strike on rotation.

--
Perry = Mick
http://www.ductedfan.com=

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