X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from elasmtp-spurfowl.atl.sa.earthlink.net ([209.86.89.66] verified) by logan.com (CommuniGate Pro SMTP 5.1.11) with ESMTP id 2240955 for flyrotary@lancaironline.net; Fri, 03 Aug 2007 18:55:10 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.66; envelope-from=Dastaten@earthlink.net Received: from [64.91.205.149] (helo=[192.168.1.100]) by elasmtp-spurfowl.atl.sa.earthlink.net with asmtp (Exim 4.34) id 1IH62T-0000H9-8f for flyrotary@lancaironline.net; Fri, 03 Aug 2007 18:54:33 -0400 Message-ID: <46B3B206.3040403@earthlink.net> Date: Fri, 03 Aug 2007 17:53:58 -0500 From: David Staten User-Agent: Mozilla Thunderbird 1.0.7 (Windows/20050923) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Tips on tuning References: In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit X-ELNK-Trace: 9a30bff84e6cb88f95c85d38d22416599ef193a6bfc3dd484fba6c5b7785bb7edb7a718b1521495ea2d4e88014a4647c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 64.91.205.149 Lugging? Was this full fine? or at a coarser setting? I'm all for 3 or more blades because there is more surface area to impart thrust from. Since we have a prop disc limit of 66 inches on our airframe, adding blades is the way to go to improve thrust. There is a limit to the amount of HP a given blade can absorb and transmit. I wouldnt necessarily be opposed to trying a 6 blade variant either, provided we are making full power with our engine, or later with the turbo. Dave Bulent Aliev wrote: > I used to have the same prop as Chris IVO Magnum 68" Diameter > inflight adjustable. I felt the 3 blade configuration used to lug the > engine down. Changed it to two blade (did not want to cut the > blades). My takeoff RPM was 6,500-7000. > Buly > > On Aug 3, 2007, at 4:15 PM, Mark Steitle wrote: > >> >> >> On 8/3/07, Al Gietzen wrote: >> >> Al, >> I think Chris B. brought this up earlier today. I didn't respond, >> but you mentioned it, so then couldn't resist the urge to comment. >> To refresh everyone's memory, I have a 20B with a 76" 3-blade >> constant-speed M/T prop. So, I can dial in the prop speed desired >> and the prop controller does the rest. With it set to 2500 rpm, I'm >> seeing 7000 engine rpm on takeoff rolls. (What a sweet sound! It >> makes those Lycosaurus' sound like farm tractors.) It will turn >> about 6700 - 6800 during static runups. But this is a c/s prop, so >> your mileage may vary. >> >> Mark S. >> >> >> >> I have found that with my 66" dia – 80" pitch prop my Velocity >> doesn't move until engine rpm is somewhere upward of 1500 rpm. >> >> >> I get about 5500 static with my 20B, and about 5600 on takeoff. >> With adjustable pitch you will want to get some higher numbers. >> >> >> Hope you find this helpful, >> >> >> Al >> >> >> > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html >