Return-Path: Received: from wb1-a.mail.utexas.edu ([128.83.126.134] verified) by logan.com (CommuniGate Pro SMTP 4.2b3) with ESMTP-TLS id 3220435 for flyrotary@lancaironline.net; Fri, 07 May 2004 14:38:10 -0400 Received: (qmail 28033 invoked from network); 7 May 2004 18:38:08 -0000 Received: from dhcp-191-101.per.utexas.edu (HELO benefits3.mail.utexas.edu) (146.6.191.101) by wb1.mail.utexas.edu with RC4-SHA encrypted SMTP; 7 May 2004 18:38:08 -0000 Message-Id: <5.1.1.5.2.20040507132612.022955a0@localhost> X-Sender: msteitle@mail.utexas.edu@localhost X-Mailer: QUALCOMM Windows Eudora Version 5.1.1 Date: Fri, 07 May 2004 13:37:10 -0500 To: "Rotary motors in aircraft" From: Mark Steitle Subject: Re: [FlyRotary] Re: Coolant Pressure Gauge In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Tony, Yes, I am looking for some larger pulleys for the ND alternators (anybody know a source for these). The water pump pulley only clears the e-shaft pulley by about 1/8", so in order to go with a larger wp plulley I would have to reduce the size of the e-shaft pulley too. I think the wp pulley will be ok as is, provided the high rpm doesn't cause cavitation. I really don't think that cavitation will be a problem, although I do have a 13B pump housing that was destroyed by cavitation. I suspect that may have been caused by air in the system. I'll have to inspect for that at regular intervals. Mark S. At 06:54 PM 5/7/2004 +0100, you wrote: >From: "Mark Steitle" > > > > Well, that's interesting. This reminds me of a nagging question I have > > had, but haven't asked. > > > > I was curious about the need to go to a smaller crank pulley to slow down > > the water pump and alternators. > > From memory, the crank pulley is about 5-1/2", the alternator pulleys are > > about 2-1/2", and the water pump > > pulley is about 4" diameter. > > >Hi Mark, >Just my two pennerth, > >Surely in Ed's marginal slip situation most, or all, of the slip would take >place on >the smaller pulleys and the much greater load on the alternator would make >this >slip first i.e. before the WP. Also, just an idea, is there any merit in >using slightly >larger pulleys, not huge, same ratio but more bite and more forgiving of >wear/slack? > >Just returned from hols, only 301 emails left to read, love it!! > >Cheers, > >Tony, Hebrides. > > > >> Homepage: http://www.flyrotary.com/ > >> Archive: http://lancaironline.net/lists/flyrotary/List.html