Return-Path: Sender: (Marvin Kaye) To: flyrotary Date: Thu, 28 Nov 2002 01:11:23 -0500 Message-ID: X-Original-Return-Path: Received: from [64.4.38.125] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.0.1) with ESMTP id 1887835 for flyrotary@lancaironline.net; Tue, 26 Nov 2002 21:12:12 -0500 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Tue, 26 Nov 2002 18:12:11 -0800 X-Originating-IP: [65.137.51.203] Reply-To: "Tracy Crook" From: "Tracy Crook" X-Original-To: "Rotary motors in aircraft" References: Subject: Re: More cooling system test stuff. X-Original-Date: Tue, 26 Nov 2002 21:20:18 -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: 27 Nov 2002 02:12:11.0633 (UTC) FILETIME=[65552610:01C295BA] While I've been playing with the cooling system measurements, I decided to look into a nagging symptom that I've had since building the airplane. The cooling system has never remained completely topped off and seemed to loose a small amount of coolant (~ 2 oz) on every flight. This didn't seem to be a problem because the cooling system works OK until its about two quarts low and I check and top off the system long before that happens. I have a one quart overflow bottle which is about the only size the aftermarket brands offer (I used Moroso) so I assumed this was adequate for any installation. To test this, I ran the hose from the overflow port on the overflow bottle to the cockpit and connected it to a second bottle. Sure enough, when the engine got up to full operating temperature, the hose puked a couple of ounces into the second bottle. When the engine cooled to room temperature, it recovered all the coolant in the first bottle then sucked in a bit of air. Moral of the story: Use a coolant recovery bottle larger than 1 quart. I just installed a 1.5 liter bottle. Will flight test this setup tomorrow. I also noticed that cooling was noticibly better when the system was completely full of liquid with absolutely no air in it. Even a few ounces worth of air in the system caused the coolant temp to go up about 5 - 7 degrees. The amount of air did not seem to affect it much. Anything from 3 oz to 60 oz of missing coolant has the same effect on temperature. I don't know the exact cause of this temp increase. More than 60 oz missing causes the temps to rise rapidly (I think the pump starts sucking air at this level). Tracy Crook tcrook@rotaryaviation.com www.rotaryaviation.com