X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [199.185.220.224] (HELO priv-edtnes40.telusplanet.net) by logan.com (CommuniGate Pro SMTP 5.0.4) with ESMTP id 883117 for flyrotary@lancaironline.net; Thu, 15 Dec 2005 08:18:26 -0500 Received-SPF: pass receiver=logan.com; client-ip=199.185.220.224; envelope-from=haywire@telus.net Received: from Endurance ([154.20.245.217]) by priv-edtnes40.telusplanet.net (InterMail vM.6.01.04.04 201-2131-118-104-20050224) with SMTP id <20051215131737.OJWZ9919.priv-edtnes40.telusplanet.net@Endurance> for ; Thu, 15 Dec 2005 06:17:37 -0700 From: "Todd Bartrim" To: "Rotary motors in aircraft" Subject: RE: [FlyRotary] Re: Radiator Expansion Tank Date: Thu, 15 Dec 2005 05:17:36 -0800 Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0008_01C60136.DCB0BDB0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_0008_01C60136.DCB0BDB0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Ok, thanks Al. I'd fully expected to see compound pressures, but as the pressure sensor has now failed I'll have to replace this before investigating further. Todd Yes; both during pressure test and during operation. During a pressure test, the gauge on my little battery powered air pump read 40 psi when air was escaping from the overflow bottle. Unless something else is happening, the pressures are additive. The cap controls the pressure difference between what is under the cap, and what is downstream at the overflow. The overflow from my filler neck cap connects to the overflow bottle. When there is no pressure in the overflow bottle the system pressure goes up quite rapidly to about 23# as the engine warms. As more coolant is forced into the overflow bottle, and that pressure builds, the system pressure increases. I haven't bothered to observe; but as the coolant temp drops, I expect the pressure drops quite rapidly to about the pressure that is in the overflow bottle. Al ------=_NextPart_000_0008_01C60136.DCB0BDB0 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Ok,=20 thanks Al. I'd fully expected to see compound pressures, but as the = pressure=20 sensor has now failed I'll have to replace this before investigating=20 further.
Todd
 

Yes; both = during=20 pressure test and during operation.  During a pressure test, the = gauge on=20 my little battery powered air pump read 40 psi when air was escaping = from the=20 overflow bottle. Unless something else is happening, the pressures are = additive.  The cap controls the pressure difference between what = is under=20 the cap, and what is downstream at the overflow.  The overflow = from my=20 filler neck cap connects to the overflow bottle.  When there is = no=20 pressure in the overflow bottle the system pressure goes up quite = rapidly to=20 about 23# as the engine warms.  As more coolant is forced into = the=20 overflow bottle, and that pressure builds, the system pressure = increases.=20

 

I = haven’t bothered=20 to observe; but as the coolant temp drops, I expect the pressure drops = quite=20 rapidly to about the pressure that is in the overflow=20 bottle.

 

Al

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