X-Virus-Scanned: clean according to Sophos on Logan.com From: "Steven W. Boese" Received: from [65.55.169.139] (HELO na01-bl2-obe.outbound.protection.outlook.com) by logan.com (CommuniGate Pro SMTP 6.1c3) with ESMTPS id 7450229 for flyrotary@lancaironline.net; Thu, 29 Jan 2015 20:09:31 -0500 Received-SPF: none receiver=logan.com; client-ip=65.55.169.139; envelope-from=SBoese@uwyo.edu Received: from BN3PR0501MB1139.namprd05.prod.outlook.com (25.160.113.149) by BN3PR0501MB1490.namprd05.prod.outlook.com (25.160.117.22) with Microsoft SMTP Server (TLS) id 15.1.65.19; Fri, 30 Jan 2015 01:08:57 +0000 Received: from BN3PR0501MB1138.namprd05.prod.outlook.com (25.160.113.148) by BN3PR0501MB1139.namprd05.prod.outlook.com (25.160.113.149) with Microsoft SMTP Server (TLS) id 15.1.65.19; Fri, 30 Jan 2015 01:08:56 +0000 Received: from BN3PR0501MB1138.namprd05.prod.outlook.com ([25.160.113.148]) by BN3PR0501MB1138.namprd05.prod.outlook.com ([25.160.113.148]) with mapi id 15.01.0065.013; Fri, 30 Jan 2015 01:08:56 +0000 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: swirl / expansion tank configuration Thread-Topic: [FlyRotary] Re: swirl / expansion tank configuration Thread-Index: AQHQPAvugLluX8OEeEqr8PA/LkK7kZzXzM9G Date: Fri, 30 Jan 2015 01:08:56 +0000 Message-ID: <1422580138249.77460@uwyo.edu> References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [69.146.103.188] authentication-results: lancaironline.net; dkim=none (message not signed) header.d=none;lancaironline.net; dmarc=none action=none header.from=uwyo.edu; x-dmarcaction-test: None x-microsoft-antispam: BCL:0;PCL:0;RULEID:(3005004);SRVR:BN3PR0501MB1139;UriScan:; x-exchange-antispam-report-test: UriScan:; x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:;SRVR:BN3PR0501MB1139; x-forefront-prvs: 04724A515E x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(6009001)(377454003)(92566002)(54356999)(77156002)(450100001)(90282001)(40100003)(102836002)(117636001)(76176999)(99286002)(2900100001)(88552001)(16236675004)(2950100001)(36756003)(50986999)(19625215002)(19580405001)(2656002)(87936001)(86362001)(110136001)(19627405001)(46102003)(75432002)(107886001)(122556002)(19580395003)(106116001)(89122001)(66066001)(62966003)(80792004)(19607625011);DIR:OUT;SFP:1102;SCL:1;SRVR:BN3PR0501MB1139;H:BN3PR0501MB1138.namprd05.prod.outlook.com;FPR:;SPF:None;MLV:sfv;LANG:en; Content-Type: multipart/alternative; boundary="_000_142258013824977460uwyoedu_" MIME-Version: 1.0 X-MS-Exchange-CrossTenant-originalarrivaltime: 30 Jan 2015 01:08:56.0341 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: f9cdd7ad-825d-4601-8e9c-a325e02d52da X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN3PR0501MB1139 Return-Path: SBoese@uwyo.edu X-Microsoft-Antispam: BCL:0;PCL:0;RULEID:;SRVR:BN3PR0501MB1490; X-OriginatorOrg: uwyo.edu --_000_142258013824977460uwyoedu_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable ?Jeff, Your sketch of my system is correct. When the engine is not running, the p= ressure in the two lines to the expansion tank are both referenced to the l= evel of the coolant in the expansion tank. This means there will be no flo= w. If the expansion tank were to fill up, where would the coolant come fro= m? It can't come from the block since it is sealed. I have not observed a= ny change in the coolant level in the expansion tank when the filler cap ha= s been left off for several days. I don't think weeks or months would make= any difference. Even when the filler cap is attached, the pressure in the= expansion tank is slightly less than atmospheric due to the coolant recove= ry action of the relief valve acting like a check valve. There is no press= ure in the expansion tank to stop backfilling when the system is cold and I= have never seen backfilling occur. You are correct that the level in the expansion tank will rise when the Sch= rader valve is opened and air is allowed to enter the block allowing coolan= t to flow out and downhill. Filling the system from bone dry has not been an issue. I just fill as mu= ch as I can into the expansion tank with the Schrader valve open (it's easi= est to just take the valve core out for this). The coolant fills the block= to the level of the coolant in the expansion tank. Coolant flows into the= block through the line connected to the expansion tank bottom. Then the S= chrader valve is sealed and the expansion tank pressurized. Air is then bl= ed out of the Schrader valve. The volume of air that is bled out is usuall= y less than the capacity of the expansion tank so the tank normally does no= t have to be refilled and repressurized, although that can be done if neces= sary. There normally is some air in the hoses to the radiators that is not= purged by this method. Running the engine up to a temperature such that t= he thermostat opens results in this air being transferred to the expansion = tank. This transfer hasn't caused the expansion tank to go dry, for me at = least. Running the engine up to temperature once has been enough to purge = the air from the system. I have also flown the plane with the filler cap loose. This caused no ill = effect such as coolant loss or overheating. The pressure reading of the ex= pansion tank just stayed at zero. I wish I could claim that this was inten= tionally done as a data gathering experiment. That was not the case, howev= er. Steve ________________________________ From: Rotary motors in aircraft on behalf of = Jeff Whaley Sent: Thursday, January 29, 2015 2:37 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: swirl / expansion tank configuration Hi Steve, I've attached a sketch of our two systems as I understand them. = Your system is equivalent to a gas can turned upside down with a very small= outlet hose and the air cap sealed tight - no, or at least very little flo= w out the bottom. I'm pretty sure if you de-pressurize your system, remove= the expansion tank cap and come back 2-3 weeks later, the level in the exp= ansion tank will have increased. You won't see any change during a quick t= op-off in a couple minutes. If you open your Schrader valve it will overf= low in a few seconds. I understand your systems' equilibrium once it is to= pped-up and you are in maintenance-mode - but how do you fill your engine w= hen bone-dry? I assume you close/pinch the lower hose and fill the block fr= om the top as complete as possible; at this point you can seal the Schrader= valve, add coolant to expansion tank, open lower hose, pressurize it and f= orce it into bottom of engine while slowly opening Schrader valve. Jeff --_000_142258013824977460uwyoedu_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

​Jeff,


Your sketch of my system is correct.  When the engine is not runnin= g, the pressure in the two lines to the expansion tank are both referenced = to the level of the coolant in the expansion tank.  This means there w= ill be no flow.  If the expansion tank were to fill up, where would the coolant come from?  It can't come from th= e block since it is sealed.  I have not observed any change in the coo= lant level in the expansion tank when the filler cap has been left off= for several days.  I don't think weeks or months would make any difference.  Even when the filler cap is attached, the= pressure in the expansion tank is slightly less than atmospheric due = to the coolant recovery action of the relief valve acting like a check valv= e.  There is no pressure in the expansion tank to stop backfilling when the system is cold and I have never see= n backfilling occur.   


You are correct that the level in the expansion tank will rise when the&= nbsp;Schrader valve is opened and air is allowed to enter the block al= lowing coolant to flow out and downhill.


Filling the system from bone dry has not been an issue.  I just&nbs= p; fill as much as I can into the expansion tank with the Schrader valve op= en (it's easiest to just take the valve core out for this).  The coola= nt fills the block to the level of the coolant in the expansion tank.  Coolant flows into the block through the= line connected to the expansion tank bottom.  Then the Schrader = valve is sealed and the expansion tank pressurized.  Air is then = bled out of the Schrader valve.  The volume of air that is bled out is usually less than the capacity of the expansion tank so the tank no= rmally does not have to be refilled and repressurized, although that can be= done if necessary.  There normally is some air in the hoses to t= he radiators that is not purged by this method.  Running the engine up to a temperature such that the thermostat opens= results in this air being transferred to the expansion tank.  This tr= ansfer hasn't caused the expansion tank to go dry, for me at least.&nb= sp; Running the engine up to temperature once has been enough to purge the air from the system.


I have also flown the plane with the filler cap loose.  This caused= no ill effect such as coolant loss or overheating.  The pressure read= ing of the expansion tank just stayed at zero.  I wish I could cl= aim that this was intentionally done as a data gathering experiment.  That was not the case, however.


Steve     

From: Rotary motors in ai= rcraft <flyrotary@lancaironline.net> on behalf of Jeff Whaley <fly= rotary@lancaironline.net>
Sent: Thursday, January 29, 2015 2:37 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: swirl / expansion tank configuration
 

Hi Steve, I’ve attached a sketch of our two sy= stems as I understand them.  Your system is equivalent to a gas can tu= rned upside down with a very small outlet hose and the air cap sealed tight= – no, or at least very little flow out the bottom.  I’m pretty sure if you de-pressurize your system, remove the expansi= on tank cap and come back 2-3 weeks later, the level in the expansion tank = will have increased.  You won’t see any change during a quick to= p-off in a couple minutes.   If you open your Schrader valve it will overflow in a few seconds.  I understand your systems&#= 8217; equilibrium once it is topped-up and you are in maintenance-mode R= 11; but how do you fill your engine when bone-dry? I assume you close/pinch= the lower hose and fill the block from the top as complete as possible; at this point you can seal the Schrader valve, add c= oolant to expansion tank, open lower hose, pressurize it and force it into = bottom of engine while slowly opening Schrader valve.

Jeff

 


--_000_142258013824977460uwyoedu_--