Return-Path: <13brv3@bellsouth.net> Received: from imf22aec.mail.bellsouth.net ([205.152.59.70] verified) by logan.com (CommuniGate Pro SMTP 4.2b3) with ESMTP id 85749 for flyrotary@lancaironline.net; Sun, 23 May 2004 10:38:36 -0400 Received: from rad ([65.6.194.9]) by imf22aec.mail.bellsouth.net (InterMail vM.5.01.06.08 201-253-122-130-108-20031117) with ESMTP id <20040523143832.COEO1774.imf22aec.mail.bellsouth.net@rad> for ; Sun, 23 May 2004 10:38:32 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: engine mount geometry Date: Sun, 23 May 2004 09:36:30 -0500 Message-ID: <014601c440d3$568a5540$6001a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0147_01C440A9.6DB44D40" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 This is a multi-part message in MIME format. ------=_NextPart_000_0147_01C440A9.6DB44D40 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable mike McGee and I were just talking about my setup, I.e. going from a = left turning mount to a right. he pointed out that this is exactly what = Tracy just did with his -4. we guessed that he didn't change the engine mount geometry, but perhaps offset the vert stab instead. =20 =20 Actually, Tracy has no offset in his RV-4 mount, or his vert stab. He originally had a small wedge type trim tab on his rudder which worked = fine until he changed drives. Now he's moved that wedge to the other side of = the rudder, and it isn't quite big enough for the new drive and prop. No surprise there I guess. Now, I believe he's in the same boat we are = for his RV-8 mount, as I think it has left offset built in. =20 =20 I would like to hear what you guys say about this geometry. does the = vert stab offset create drag? is one way better than another? will higher cruise speeds affect the alignment, I know it affects rudder trim? Kevin Lane Portland, OR=20 =20 I'd like to know this as well. As far as I can tell, offsetting the = vert stab is no different than applying some rudder trim, which I can = certainly do. The real question for me is whether the engine offset is any better than rudder trim, in terms of drag at cruise speed. =20 =20 Cheers, Rusty (making the TB flange, and fitting the tubes later this afternoon) = =20 ------=_NextPart_000_0147_01C440A9.6DB44D40 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
mike McGee and I were just = talking about=20 my setup, I.e. going from a left turning mount to a right.  he = pointed out=20 that this is exactly what Tracy just did with his -4.  we guessed = that he=20 didn't change the engine mount geometry, but perhaps offset the vert = stab=20 instead.   
 
Actually, Tracy has no offset in his RV-4 = mount, or his=20 vert stab.  He originally had a small wedge type trim tab = on his=20 rudder which worked fine until he changed drives.  Now he's moved = that=20 wedge to the other side of the rudder, and it isn't quite big enough for = the new=20 drive and prop.  No surprise there I guess.   Now, I = believe he's=20 in the same boat we are for his RV-8 mount, as I think it has left = offset built=20 in. 
 
 I=20 would like to hear what you guys say about this geometry.  does the = vert=20 stab offset create drag?  is one way better than another?  = will higher=20 cruise speeds affect the alignment, I know it affects rudder = trim?
Kevin Lane  Portland, OR 
 
I'd like=20 to know this as well.  As far as I can tell, offsetting the = vert stab=20 is no different than applying some rudder trim, which I can = certainly=20 do.  The real question for me is whether the engine offset is = any=20 better than rudder trim, in terms of drag at cruise=20 speed.  
 
Cheers,
Rusty (making=20 the TB flange, and fitting the tubes later this=20 afternoon)   
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