Return-Path: Received: from mail.viclink.com ([66.129.220.6] verified) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 3064239 for flyrotary@lancaironline.net; Fri, 05 Mar 2004 00:34:52 -0500 Received: from mail.viclink.com (p004.AS1.viclink.com [66.129.192.4]) by mail.viclink.com (8.11.7/8.11.7) with ESMTP id i255Yb153912 for ; Thu, 4 Mar 2004 21:34:37 -0800 (PST) Message-ID: <40481128.3040707@mail.viclink.com> Date: Thu, 04 Mar 2004 21:33:28 -0800 From: Perry Mick User-Agent: Mozilla/5.0 (Windows; U; Win95; en-US; rv:1.0.1) Gecko/20020823 Netscape/7.0 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Ideal Cooling System Plumbing (was Re: [FlyRotary] Re: overflow connections References: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-RAVMilter-Version: 8.4.3(snapshot 20030217) (mail.viclink.com) Finn Lassen wrote: > David Carter wrote: > >> 3. However, with ref to my last input, "coolant level", as sensed >> inside a >> "pressurized" coolant expansion tank - IF mounted with coolant level >> up near >> top of engine , will be the ABSOLUTE first AND BEST indicator of a leak: >> Coolant leaks out - anywhere, that coolant is replaced by coolant in >> "expansion/reservoir/pump header" tank until tank empties/turns on "Low" >> light. Up to this point, the engine is FULL of liquid - no air, no >> nucleate >> boilng, no temp jiggles. Then subsequent leakage will be out of >> engine, as >> "expansion/reservoir" tank is now empty - THEN, the PRESSURE jiggles >> will >> start. >> >> David >> > However, there is one failure mode (with which I'm intimately > familiar) where sensing the coolant level in the overflow bottle (and > possibly in pressurized expansion/header tank) will not help: Blowby > from compression and/or combustion gasses forcing air into the coolant > system (and the coolant out). Actually a nice big header tank might > be able to handle or hide it and then a increasing pressure trend > would be the clue that it's getting worse and worse. > > Finn > Finn, I have personal experience with that failure mode as well. I have a relatively small overflow bottle, with the Mazda snap-on cap from the car. It has a vent outlet on it, I have this vent hooked up to a short hose and a small aluminum tube that protrudes out of the cowl near the right wing root. I can look over my shoulder while flying and see this vent. If the overflow bottle fills up and coolant starts coming out of this vent, I know things are not normal. -- Perry Mick http://www.ductedfan.com