X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao101.cox.net ([68.230.241.45] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2362482 for flyrotary@lancaironline.net; Mon, 01 Oct 2007 13:58:03 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.45; envelope-from=alventures@cox.net Received: from fed1rmimpo01.cox.net ([70.169.32.71]) by fed1rmmtao101.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20071001175724.DMUJ13309.fed1rmmtao101.cox.net@fed1rmimpo01.cox.net> for ; Mon, 1 Oct 2007 13:57:24 -0400 Received: from BigAl ([72.192.143.193]) by fed1rmimpo01.cox.net with bizsmtp id v5xQ1X0094AaN600000000; Mon, 01 Oct 2007 13:57:24 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] motor decisions! Date: Mon, 1 Oct 2007 10:58:11 -0800 Message-ID: <000001c8045d$036995a0$6401a8c0@BigAl> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 Andrew; It may make a difference on what the plane is; and on how high you = intend to fly. I have a 20B on a Velocity SE RG, which also has the IO360 as the recommended engine. I think the choice is not just 20B vs 13B; but = rather vs turbocharged 13B. A NA 13B is probably not in the running, especially = for high altitude cruise. If you are going to have O2, and like to fly = those x-country trips above about 12,500, go with the turbo 13B (with intercooler), because it will give more power up there as the NA 20B = with a less weight. I'd also suggest that a renesis with a 2.81 (or higher) redrive ratio = may be an excellent choice. New engines available for less than you could = get for your 20B, and NA should give you 20-30 more HP than the IO360 at = less weight. The all-up NA 20B will weigh about 50 lbs more than the IO360. Al -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Andrew Martin Sent: Monday, October 01, 2007 9:21 AM To: Rotary motors in aircraft Subject: [FlyRotary] motor decisions! Hi=20 I have a 20b and about to start building a plane that is designed for a IO 360. It has been suggested to me that I should change to a 2 rotor to save weight. I=92ve gone through the archives but didn=92t really find = any pro=92 and con=92s of 3 or 2 rotors other than the max power available. The plane will be used almost exclusively for long X-country cruising once the bugs are worked out and hours flown off. =20 If my estimated max power required due to VNE is around 200hp, is the Renesis always the engine of choice or are there advantages to keeping the 20b, accepting the weight penalty and letting the engine loaf along. I originally presumed the 20b would be better for me especially when at my gross weight of 2420 lbs. but now I am unsure, so to change now rather than later would be easier. Any help from anyone flying either engine, and points that governed your engine of choice would be greatly appreciated. =20 Regards Andrew Martin Western Australia =A0 =A0 -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html