Return-Path: Sender: (Marvin Kaye) To: flyrotary@lancaironline.net Date: Mon, 08 Mar 2004 22:07:36 -0500 Message-ID: X-Original-Return-Path: Received: from avocet.mail.pas.earthlink.net ([207.217.120.50] verified) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 3069840 for flyrotary@lancaironline.net; Mon, 08 Mar 2004 21:55:41 -0500 Received: from user-33qt4jd.dialup.mindspring.com ([199.174.146.109] helo=Carol) by avocet.mail.pas.earthlink.net with smtp (Exim 3.33 #1) id 1B0XPA-0004iw-00 for flyrotary@lancaironline.net; Mon, 08 Mar 2004 18:55:40 -0800 X-Original-Message-ID: <00fa01c40581$fb7586c0$0000a398@Carol> From: "sqpilot@earthlink" X-Original-To: "flyrotary" Subject: air pocket in cooling system X-Original-Date: Mon, 8 Mar 2004 20:55:28 -0600 MIME-Version: 1.0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2720.3000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2727.1300 Hi, fellow rotary enthusiasts. I decided to temporarily take the thermostat out of my 13b for initial run-ups, testing and ECU programming. When I removed the thermostat, there was coolant right up to the bottom edge of the thermostat. However, you could look up and see the water temp sensor, and it was in an air pocket. I've been following the many posts that are currently being sent discussing cooling issues. I have installed the "closed" system, with a pressurized expansion tank with the radiator cap on the aluminum expansion tank, and no additional overflow bottle. From what I am reading, it sounds like a few short runs should eliminate this small pocket of air, and only take a small amount of coolant from my expansion tank. I am assuming that since the coolant is all the way up to the bottom of where the thermostat normally would be, that the water pump is fully immersed, and should start pumping coolant as soon as I start the engine. I would assume that this would be turbulent enough to splash coolant up into this small air pocket so that the coolant sensor will be touching coolant? I am rather surprised that Mazda put the sensor in this location, in that it is so high that if there is any air in the system, that's where it's likely to be. Maybe Mazda wants us to know the air temp inside the engine? (Only kidding) If all this sounds correct, my question would be mainly: how long or short of a duration should these runs be to try to purge the air out of the system? Are we talking about something like 60 seconds or more like 5 minutes ? I installed a "real" throttle cable and throttle assembly today. No more coat hanger run-ups. Thanks so much for everyones assistance here. Paul Conner, 13b powered SQ2000 canard