Return-Path: Received: from [128.83.126.208] (HELO mail.utexas.edu) by logan.com (CommuniGate Pro SMTP 4.2b3) with ESMTP-TLS id 3221681 for flyrotary@lancaironline.net; Sat, 08 May 2004 11:08:37 -0400 Received: (qmail 95883 invoked by uid 80); 8 May 2004 15:08:36 -0000 Received: from dial-76-4.ots.utexas.edu (dial-76-4.ots.utexas.edu [128.83.254.116]) by webmailapp5.cc.utexas.edu (IMP) with HTTP for ; Sat, 8 May 2004 10:08:36 -0500 Message-ID: <1084028916.409cf7f451b86@webmailapp5.cc.utexas.edu> Date: Sat, 8 May 2004 10:08:36 -0500 From: msteitle@mail.utexas.edu To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: E-shaft pulley diameters References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit User-Agent: Internet Messaging Program (IMP) 3.2.2 X-Originating-IP: 128.83.254.116 Quoting Al Gietzen : > Subject: [FlyRotary] Re: E-shaft pulley diameters > > > > Al, > That's probably good advice. Do you know what other 20B guys are doing? I > only know of Tom Parkes that has actually flown. I think I have his e-mail > address and can ask him about his pulley arrangement. > > Thanks, > Mark > > > > > I don't know what others are doing. I got a 3" double sheave pulley for the > alternator from Racing Beat. Having decided to dis the smog pump (vacuum > pump) in favor of all electric, It made sense to go to double belt on the > alternator. Water pump is also 3" and e-shaft is 4-1/2" > > > > Al > > Al, Measured my e-shaft pulley at 5-1/4", and the wp pulley at 3-7/8". The alternator pulleys are 2-1/4 and 2". I tried mixing and matching some single and double-V pulleys I had from a junker 13B with some interesting discoveries. First, the water pump pulley wouldn't fit all the way down onto the 20b pump. I could prbably make it fit by grinding down some of the webs on the wp housing, but I don't want to do that for obvious reasons. One solution would be to change to the 13B pump and housing, but that would require a number of other changes in the cooling system, so I don't want to do that either. Due to mis-alignment of the pulleys, in order to use the double-v crank pulley, it would require repositioning of both alternators. That would be very difficult to do. So I think the best approach is to locate some oversized alternator pulleys for the dual ND alternators (multi-v style). And if I can't locate a source (at a reasonable price), then I'll make them myself. And for now, I'll leave the wp pulley and crank pulley as is. Mark S.