X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 19 Jun 2013 14:14:36 -0400 Message-ID: X-Original-Return-Path: Received: from qmta02.westchester.pa.mail.comcast.net ([76.96.62.24] verified) by logan.com (CommuniGate Pro SMTP 6.0.5) with ESMTP id 6332833 for lml@lancaironline.net; Wed, 19 Jun 2013 10:48:04 -0400 Received-SPF: pass receiver=logan.com; client-ip=76.96.62.24; envelope-from=mjrav@comcast.net Received: from omta02.westchester.pa.mail.comcast.net ([76.96.62.19]) by qmta02.westchester.pa.mail.comcast.net with comcast id qBor1l0010QuhwU51EnVTl; Wed, 19 Jun 2013 14:47:29 +0000 Received: from MarkRavinskiPC ([66.30.31.1]) by omta02.westchester.pa.mail.comcast.net with comcast id qEnU1l01E01T6pe3NEnVff; Wed, 19 Jun 2013 14:47:29 +0000 X-Original-Message-ID: <4B5624A2E33642E581EAA1CBDE73D9DB@MarkRavinskiPC> From: "Mark Ravinski" X-Original-To: "Lancair Mailing List" References: In-Reply-To: Subject: Re: [LML] Re: Propeller choice for Lancair 320 and Back Plate failures X-Original-Date: Wed, 19 Jun 2013 10:48:27 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0025_01CE6CDA.87607900" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8089.726 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8089.726 This is a multi-part message in MIME format. ------=_NextPart_000_0025_01CE6CDA.87607900 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Nick, I've been in 14 races over the years behind Hartzel. Airventure Cup and = Sun 100 mostly. The Hartzel props do consistently beat the MT props by a hair. However, = most of us agree the 3 blades look better. Lately, I've gone to a Cato fixed pitch composite prop 68". You loose takeoff and some landing performance but more than make up for = it in cruise speed , fuel economy, light weight, lower vibration and low = cost. Mark Ravinski 360 1539 hrs From: Nick Long=20 Sent: Tuesday, June 18, 2013 4:59 PM To: lml@lancaironline.net=20 Subject: [LML] Re: Propeller choice for Lancair 320 and Back Plate = failures Thanks Dan, That=E2=80=99s all useful info. At first, one would be tempted to say = that 3-4 knots is not significant, but if it is repeatable.... I remember years ago some of us wondering why one aircraft was faster = than another and swapping supposedly identical props between supposedly = identical aircraft, then flying in formation and finding one prop was = always 3 or 4 knots better. Nick From: Dan & Kari Olsen=20 Sent: Tuesday, June 18, 2013 6:47 PM To: lml@lancaironline.net=20 Subject: [LML] Re: Propeller choice for Lancair 320 and Back Plate = failures Nick, =20 I=E2=80=99ve got a Lancair 320 with the IO-320-D1B 160hp engine and the = Hartzell 70=E2=80=9D prop that Lancair and Hartzell approved for this = airframe and engine. I=E2=80=99m very pleased with the performance. A = friend of mine has the same airframe and engine as I do but has the MT = 3-blade prop. When we fly formation at exactly the same power settings, = I am pulling away from him at about 3-4kts. We haven=E2=80=99t tried a = side-by-side climb comparison but the 2-blade Hartzell is definitely a = bit faster in cruise than the 3-blade Hartzell, just as prop theory = would suggest. =20 When I built the plane I was concerned about spinner wobble and = stresses, so I created a little donut inside the spinner that fits = snugly around the prop hub. You can see a photo of it here: = http://lancair.net/pix/olsen/olsen-construction. After 720hrs on the = airplane I have had no problems with spinner or cracking. =20 Cheers! =20 Dan Olsen Fort Collins, CO N320DK, 320 MKII, 720hrs N630DK, IV-P, 20% complete =20 =20 =20 ------=_NextPart_000_0025_01CE6CDA.87607900 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Nick,
I've been in 14 races over the years behind=20 Hartzel.  Airventure Cup and Sun 100 mostly.
The Hartzel props do consistently beat the MT = props by a=20 hair.  However, most of us agree the 3 blades look = better.
Lately, I've gone to a Cato fixed pitch = composite prop=20 68".
You loose takeoff and some landing performance = but more=20 than make up for it in cruise speed , fuel economy, light weight, lower=20 vibration and low cost.
 
Mark Ravinski
360  1539 hrs

From: Nick Long
Sent: Tuesday, June 18, 2013 4:59 PM
To: lml@lancaironline.net
Subject: [LML] Re: Propeller choice for Lancair 320 and Back = Plate=20 failures

Thanks Dan,
 
That=E2=80=99s all useful info. At first, one would be tempted to = say that 3-4=20 knots is not significant, but if it is repeatable....
I remember years ago some of us wondering why one aircraft was = faster than=20 another and swapping supposedly identical props between supposedly = identical=20 aircraft, then flying in formation and finding one prop was always 3 or = 4 knots=20 better.
 
Nick
 
 
Sent: Tuesday, June 18, 2013 6:47 PM
Subject: [LML] Re: Propeller choice for Lancair 320 and Back = Plate=20 failures
 

Nick,

 

I=E2=80=99ve got a Lancair 320 with the IO-320-D1B = 160hp engine and=20 the Hartzell 70=E2=80=9D prop that Lancair and Hartzell approved for = this airframe and=20 engine.  I=E2=80=99m very pleased with the performance.  A = friend of mine has=20 the same airframe and engine as I do but has the MT 3-blade prop.  = When we=20 fly formation at exactly the same power settings, I am pulling away from = him at=20 about 3-4kts.  We haven=E2=80=99t tried a side-by-side climb = comparison but the=20 2-blade Hartzell is definitely a bit faster in cruise than the 3-blade = Hartzell,=20 just as prop theory would suggest.

 

When I built the plane I was concerned about = spinner wobble=20 and stresses, so I created a little donut inside the spinner that fits = snugly=20 around the prop hub.  You can see a photo of it here: http://lancair.n= et/pix/olsen/olsen-construction. =20 After 720hrs on the airplane I have had no problems with spinner or=20 cracking.

 

Cheers!

 

Dan Olsen

Fort Collins, CO

N320DK, 320 MKII, 720hrs

N630DK, IV-P, 20% complete

 

 

 

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