Return-Path: Sender: (Marvin Kaye) To: flyrotary Date: Fri, 29 Nov 2002 22:13:05 -0500 Message-ID: X-Original-Return-Path: Received: from [64.4.38.195] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.0.2) with ESMTP id 1890621 for flyrotary@lancaironline.net; Thu, 28 Nov 2002 11:27:17 -0500 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Thu, 28 Nov 2002 08:27:16 -0800 X-Originating-IP: [65.137.51.64] Reply-To: "Tracy Crook" From: "Tracy Crook" X-Original-To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Coolant loss : More cooling system test stuff. X-Original-Date: Thu, 28 Nov 2002 11:35:52 -0500 Organization: Real World Solutions Inc. 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 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-Original-Message-ID: X-OriginalArrivalTime: 28 Nov 2002 16:27:16.0391 (UTC) FILETIME=[03C3B370:01C296FB] ----- Original Message ----- From: "Peter Cowan" > .Tracy and others, what is the theory behind so much liquid in the external > expansion tank? Thermal expansion of the initial coolant volume doesn't > account for such a large overflow. So is vapor building up inside? If it is > there is no longer a liquid filled system. I don't get it. > Peter I'm not 100% sure what is going on but I think you would be surprised how much the 50-50 coolant expands with heat. I flight tested the new bottle yesterday and verified that on cooldown the system was completely topped off with coolant (no air at top of fill port.) This was never the case before. This also accounts for another anomaly I've noticed over the years. It seemed like the water cooling was slightly better on the first flight after topping off the system. I was never sure because the next flight was usually on a different day, different temperature, humidity, etc. Now that I've been paying close attention I have verified that only a few ounces worth of air in the system makes a noticible degredation in cooling performance (about 5 degrees worth). Not sure why this is happening either but I'm happy with the results. With more experimentation the answer will probably come out. Tracy Crook tcrook@rotaryaviation.com www.rotaryaviation.com