Return-Path: Received: from pop3.olsusa.com ([63.150.212.2] verified) by logan.com (CommuniGate Pro SMTP 3.5.2) with ESMTP id 1031020 for rob@logan.com; Fri, 25 Jan 2002 19:11:23 -0500 Received: from smtp.olsusa.com ([63.150.212.3]) by pop3.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-71866U8000L800S0V35) with ESMTP id com for ; Fri, 25 Jan 2002 18:22:00 -0500 Received: from WS_01.olsusa.com ([207.30.195.52]) by smtp.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-71866U8000L800S0V35) with ESMTP id com for ; Fri, 25 Jan 2002 18:20:18 -0500 Message-Id: <5.0.0.25.2.20020125182552.00a58b90@127.0.0.1> Date: Fri, 25 Jan 2002 18:32:32 -0500 To: lancair.list@olsusa.com From: Paul Kapcin Subject: Constant Speed Prop Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed X-Mailing-List: lancair.list@olsusa.com Reply-To: lancair.list@olsusa.com <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> Reposted for , CavittP@aol.com Fixed pitch prop just as good as a constant speed? In the case of my Lancair-235/320 (150HP), with a Demuth 62x76 fixed pitch prop, at all field elevations, I get 2250 RPM static. At SL, this translates to about 108 HP initially and gradually increases during acceleration -- takeoff run is about 1000,' but at 105 KIAS (VY) I get about 2500 RPM and 1500 FPM up through about 3000' at gross weight. If I accelerate to about 140 KIAS I am able to sustain 1000 FPM up through 10,000' ending up with 105 KIAS at top of climb. In cruise at all altitudes up to 10,000' with about 2700 RPM, I get a TAS of 180 - 185 KTAS with about 1/3 throttle travel remaining. My main destinations are Tucson (2500 MSL) where it takes a ground run of about 2000' in winter and 2500 in summer. Flagstaff (7000 )where take off run is about 3000' in winter (haven't tried in summer yet). Imagine getting only 2250 RPM static at 7000 MSL. What HP would that translate to? Not much, so if I could get 2700 RPM for takeoff, there is no doubt that I would significantly improve takeoff and climb performance. At 7000 MSL as it is, I get very slow acceleration and initial climb is less than 500 FPM until I get over 105 KIAS at which time it slowly increases to just under 700 FPM. Once accelerated to about 120 KIAS the climb rate stabilizes to about 1000 FPM and RPM is about 2500 RPM. In cruise, if I could advance that 1/3 remaining throttle travel, imagine how much more speed I would realize... Hmmm... Pete Cavitt - N320PL >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML website: http://members.olsusa.com/mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please remember that purchases from the Builders' Bookstore assist with the management of the LML. Please send your photos and drawings to marvkaye@olsusa.com. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>