X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [66.37.197.101] (HELO o1.xlccorp.com) by logan.com (CommuniGate Pro SMTP 5.0.9) with SMTP id 1137624 for flyrotary@lancaironline.net; Fri, 02 Jun 2006 09:11:03 -0400 Received-SPF: none receiver=logan.com; client-ip=66.37.197.101; envelope-from=bbradburry@allvantage.com Received: (qmail 15096 invoked from network); 2 Jun 2006 13:10:13 -0000 Received: from dialup-4.235.24.10.dial1.orlando1.level3.net (HELO h2m6k0) (4.235.24.10) by o1.xlccorp.com with SMTP; 2 Jun 2006 13:10:12 -0000 Message-ID: <006601c68646$3ce04040$0a18eb04@h2m6k0> Reply-To: "Bill Bradburry" From: "Bill Bradburry" To: "Rotary motors in aircraft" References: Subject: Prop design speed Date: Fri, 2 Jun 2006 09:12:44 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1409 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 Joe Hull says: Snip... "Thanx Ed. I have a 64"Dia. x 76" pitch prop. It's supposed to be cruise prop that is designed for 190HP and 220MPH. But you're right, it's too early to be cutting on the prop." OK, here is where I demonstrate my ignorance... My rough calculations, with an estimated 20% slip, says this prop with a 76" pitch, is good for 121 MPH with a 2.85 drive and 160 MPH with a 2.17 drive assuming a 6000 RPM cruise??? Where am I going wrong? Bill Bradburry