Return-Path: Received: from [65.54.169.71] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.2b3) with ESMTP id 84534 for flyrotary@lancaironline.net; Sat, 22 May 2004 14:29:45 -0400 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Sat, 22 May 2004 11:29:39 -0700 Received: from 4.174.0.236 by bay3-dav41.bay3.hotmail.com with DAV; Sat, 22 May 2004 18:29:39 +0000 X-Originating-IP: [4.174.0.236] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: engine mount geometry Date: Sat, 22 May 2004 14:29:42 -0400 MIME-Version: 1.0 X-Mailer: MSN Explorer 7.02.0011.2700 Content-Type: multipart/alternative; boundary="----=_NextPart_001_0002_01C44009.38C00C50" Message-ID: X-OriginalArrivalTime: 22 May 2004 18:29:39.0913 (UTC) FILETIME=[BE52FB90:01C4402A] ------=_NextPart_001_0002_01C44009.38C00C50 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Mike points out the bottom line correctly. This is the only realistic ch= oice. Tracy ----- Original Message ----- From: Michael McGee Sent: Saturday, May 22, 2004 12:57 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: engine mount geometry I've got some old RV-4 plans that have the motor mount off set =20 dimensions. The prop flange stays on the centerline of the fuse/cowl and= =20 the back of the engine is off set as required for the thrust angle. Mike At 19:10 2004-05-21, you wrote: >I am fabricating the bed mount plate for my 20B in an rv-8. my >understanding, from Tracy's advice, is to offset the engine about 1 1/2 >degrees to the right if I use his 2.85 drive. as I see it there is a >centerline of the fuselage and a centerline of the engine/redrive. if I >mount them such that they are 1 1/2 degrees out of parallel, then those >centerlines will intersect. my question is where? do I offset the prop >flange 5/8" to 1", then draw an offset centerline back from there? do I >draw an offset line forward from the firewall, or from the center of gra= vity >of the engine? do I attempt to keep the engine "balanced" left and righ= t >along the centerline of the fuselage? I don't think I have ever seen th= is >topic discussed more than "offset the engine". my prop flange will be a= bout >40" forward of the firewall. >in attempting to see what had been done with the current left offset mou= nt, >it appears that the intersection of centerlines is close to the forward = end >of the engine. >I originally bought the mount thinking a 2.15, left turning, redrive wou= ld >be used. Fred Breese is being, well, a dick about it, and tells me it i= s >way too complicated for me to understand and I need to simply buy a new >mount. no surprise, this isn't the first time he has treated me poorly.= no >wonder I'm building my own plate rather than buy his $500 one. I'd like= to >hear why I need a new mount. true the ears will be of different lengths= , >but it is hard to believe the 5/8ths plate I am using will ever break. = has >anyone ideas? >Kevin Lane Portland, OR >e-mail-> n3773@comcast.net >web-> http://home.comcast.net/~n3773 >(browse w/ internet explorer) > > > >> Homepage: http://www.flyrotary.com/ > >> Archive: http://lancaironline.net/lists/flyrotary/List.html >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_001_0002_01C44009.38C00C50 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Mike points ou= t the bottom line correctly. This is the only realistic choice.

Tracy

-= ---- Original Message -----

From: Michael McGee

Sent: Saturday, May 22, 2004 12:57 AM
To: Rotary motors in aircraft

<= DIV style=3D"FONT: 10pt Arial">Subject: [FlyRotary] Re: engine mou= nt geometry

I've got some old RV-4 plans that have= the motor mount off set
dimensions. The prop flange stays on t= he centerline of the fuse/cowl and
the back of the engine is off set = as required for the thrust angle.

Mike

At 19:10 2004-05-21,= you wrote:
>I am fabricating the bed mount plate for my 20B in an = rv-8. my
>understanding, from Tracy's advice, is to offset th= e engine about 1 1/2
>degrees to the right if I use his 2.85 drive.= as I see it there is a
>centerline of the fuselage and a cen= terline of the engine/redrive. if I
>mount them such that the= y are 1 1/2 degrees out of parallel, then those
>centerlines will i= ntersect. my question is where? do I offset the prop
>f= lange 5/8" to 1", then draw an offset centerline back from there? d= o I
>draw an offset line forward from the firewall, or from the cen= ter of gravity
>of the engine? do I attempt to keep the engin= e "balanced" left and right
>along the centerline of the fuselage?&= nbsp; I don't think I have ever seen this
>topic discussed more tha= n "offset the engine". my prop flange will be about
>40" forw= ard of the firewall.
>in attempting to see what had been done with = the current left offset mount,
>it appears that the intersection of= centerlines is close to the forward end
>of the engine.
>I o= riginally bought the mount thinking a 2.15, left turning, redrive would>be used. Fred Breese is being, well, a dick about it, and tel= ls me it is
>way too complicated for me to understand and I need to= simply buy a new
>mount. no surprise, this isn't the first t= ime he has treated me poorly. no
>wonder I'm building my own = plate rather than buy his $500 one. I'd like to
>hear why I n= eed a new mount. true the ears will be of different lengths,
>= ;but it is hard to believe the 5/8ths plate I am using will ever break.&n= bsp; has
>anyone ideas?
>Kevin Lane Portland, OR
>= ;e-mail-> n3773@comcast.net
>web-> http://home.comcast.net/~n= 3773
>(browse w/ internet explorer)
>
>
> >>= ; Homepage: http://www.flyrotary.com/
> >> = Archive: http://lancaironline.net/lists/flyrotary/List.html

>> Homepage: http://www.flyrotary.com/>> Archive: http://lancaironline.net/lists/flyro= tary/List.html
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