Return-Path: Received: from smtp.acd.net ([207.179.64.154] verified) by logan.com (CommuniGate Pro SMTP 4.3c3) with ESMTP id 851936 for flyrotary@lancaironline.net; Fri, 01 Apr 2005 14:25:08 -0500 Received-SPF: none receiver=logan.com; client-ip=207.179.64.154; envelope-from=rjechtinaw@ia4u.net Received: from [207.179.99.99] ([207.179.99.99]) by smtp.acd.net with Microsoft SMTPSVC(5.0.2195.6713); Fri, 1 Apr 2005 14:21:51 -0500 Mime-Version: 1.0 (Apple Message framework v619.2) In-Reply-To: References: Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: Content-Transfer-Encoding: 7bit From: randy echtinaw Subject: Re: [FlyRotary] Re: Davies-Craig EWP Test Results Date: Fri, 1 Apr 2005 14:23:27 -0500 To: "Rotary motors in aircraft" X-Mailer: Apple Mail (2.619.2) Return-Path: rjechtinaw@ia4u.net X-OriginalArrivalTime: 01 Apr 2005 19:21:51.0810 (UTC) FILETIME=[0ECA0A20:01C536F0] Gentlemen, I will try to phrase this question so as not to reveal my stupidity but - if you are going to test EWP's and EDWP's for pressure, volume and amp draw comparisons why not set them up with an engine block and a couple of radiators and get some real factual data from these comparisons. I am failing to see what the value of the tests are when pumping from a barrel of water to another barrel. The very best test would be to use a running engine installed on an aircraft and keep changing the pumps and recording the data. There must be someone out there with nothing else to do :) Thank you, Randy On Apr 1, 2005, at 1:30 PM, DaveLeonard wrote: > Bob, Jim is right. The best way is a flow vs. pressure. The work to > get > the fluid through the entire system is likely going to be more than > what you > tested. I will bet dollars for doughnuts that the more > expensive/larger > pump will perform better at the higher pressures. > > Think of the difference between a cheap handheld electric drill, and a > drill > press. Under no load, the hand-held drill spins much faster than the > drill > press. But put on a load and the small drill quickly slows down and > stops, > the drill press is unaffected. > > Dave Leonard > > >> >> >> It would be interesting to put a valve downstream from the pump and >> close it just a tad (perhaps measure pressure drop across the valve or >> perhaps across the pump) and see how a restriction affects flow. >> Inquiring minds need to know :o) ... Jim S. >> >> Bob White wrote: >> >>> Hi Dave, >>> >>> The only restriction was the hoses I used for the test and the >> flow meter. Flow >>> was out of the bucket about an inch from the bottom thru the >> test setup and back >>> into the top of the bucket with the hose submerged. The hose >> sizes are similar >>> to what I'm planning on using in the plane. >>> >>> Bob W. >>> >>> >>> On Thu, 31 Mar 2005 05:38:42 -0800 >>> "DaveLeonard" wrote: >>> >>> >>> >>>> MessageBob was there any resistance to flow? The could perform >>>> quite >>>> differently if they are pumping against resistance. >>>> >>>> Dave Leonard >>>> >>>> Th e tiny D-C pump outperforms the WP136. >>>> >>>> Great report Bob! Sounds like the little plastic Davies >> Craig pump is the >>>> hands down winner over the WP136 Meziere. I'm not too >> concerned about the >>>> motor temp, because it's obviously made to run that hot, and >> still give good >>>> service life. The best part about the test is that you did it, >> and my WP136 >>>> is still new in the box. Now I can send it back to Summit for >> a refund :-) >>>> >>>> Cheers, >>>> Rusty (hoping for two successful posts in a row) >>>> >>>> >>>> >>> >>> >>> >>> >> >>>> Homepage: http://www.flyrotary.com/ >>>> Archive: http://lancaironline.net/lists/flyrotary/List.html > > >>> Homepage: http://www.flyrotary.com/ >>> Archive: http://lancaironline.net/lists/flyrotary/List.html >