Return-Path: Sender: (Marvin Kaye) To: lml Date: Sat, 01 Jun 2002 00:08:46 -0400 Message-ID: X-Original-Return-Path: Received: from imo-m10.mx.aol.com ([64.12.136.165] verified) by logan.com (CommuniGate Pro SMTP 4.0b1) with ESMTP id 1253295 for lml@lancaironline.net; Fri, 31 May 2002 21:27:57 -0400 Received: from RicArgente@cs.com by imo-m10.mx.aol.com (mail_out_v32.5.) id q.17b.913b9e8 (30950) for ; Fri, 31 May 2002 21:27:55 -0400 (EDT) From: RicArgente@cs.com X-Original-Message-ID: <17b.913b9e8.2a297d1a@cs.com> X-Original-Date: Fri, 31 May 2002 21:27:54 EDT Subject: Re: [LML] Propeller Size X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_17b.913b9e8.2a297d1a_boundary" X-Mailer: CompuServe 2000 6.0 for Windows US sub 10511 --part1_17b.913b9e8.2a297d1a_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit My question is, Is it possible to go to a larger prop? I am going to use a constant speed prop but would prefer a larger diameter if possible (72 in.?) Has anyone explored this possibility? Mark, I have a 72-inch Hartzel prop on my Lancair 360. That was the recommended prop back then. If I can trade my prop for a 68-inch, I would do it in a second. Mainly due to the added prop-to-ground clearance. Lancair also conducted performance tests between the two prop sizes. The 68-inch prop was faster in cruise while the 72-inch prop climbed faster...(see chart below) 72-inch 68-inch Cruice@7,500 Ft (mph) (knots) (mph) (knots) 2500rpm/23.9" Hg 233 203 237 206 2500rpm/21.8" Hg 221 192 228 198 2500rpm/19.5" Hg 210 183 211 183 Cruise@12,500 Ft 2500rpm/19.5" Hg 227 197 233 203 2400rpm/19.5" Hg 223 194 227 197 2300rpm/19.5" Hg 221 192 228 198 2200rpm/19.5" Hg - 224 195 Climb: (1,000' climb from 4000 MSL) IAS 72-Inch 68-Inch (mph) (Knots) (fpm) 80 70 1670 1430 95 83 1760 1460 120 104 1880 1670 140 122 1765 1670 Rick Argente 360ZR --part1_17b.913b9e8.2a297d1a_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: 7bit My question is, Is it possible to go to a larger prop? I am going to use a constant speed prop but would prefer a larger diameter if possible (72 in.?) Has anyone explored this possibility?

Mark,

I have a 72-inch Hartzel prop on my Lancair 360.  That was the recommended prop back then.  If I can trade my prop for a 68-inch, I would do it in a second.  Mainly due to the added prop-to-ground clearance.  Lancair also conducted performance tests between the two prop sizes.  The 68-inch prop was faster in cruise while the 72-inch prop climbed faster...(see chart below)

                           72-inch             68-inch
Cruice@7,500 Ft (mph) (knots) (mph) (knots)
 2500rpm/23.9" Hg  233 203       237 206
 2500rpm/21.8" Hg  221 192       228 198
 2500rpm/19.5" Hg  210 183       211 183

Cruise@12,500 Ft
 2500rpm/19.5" Hg  227 197       233 203
 2400rpm/19.5" Hg  223 194       227 197
 2300rpm/19.5" Hg  221 192       228 198
 2200rpm/19.5" Hg -             224 195

Climb: (1,000' climb from 4000 MSL)
                  IAS    72-Inch 68-Inch
               (mph)    (Knots)       (fpm)
                 80       70     1670 1430
                 95       83     1760 1460
                120     104     1880 1670
                140     122     1765 1670



Rick Argente
360ZR --part1_17b.913b9e8.2a297d1a_boundary--