X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imo-m27.mx.aol.com ([64.12.137.8] verified) by logan.com (CommuniGate Pro SMTP 5.2.0) with ESMTP id 2756756 for flyrotary@lancaironline.net; Mon, 25 Feb 2008 12:03:14 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.8; envelope-from=BMears9413@aol.com Received: from BMears9413@aol.com by imo-m27.mx.aol.com (mail_out_v38_r9.3.) id q.d3a.1e4bdce7 (37033) for ; Mon, 25 Feb 2008 12:02:31 -0500 (EST) Received: from webmail-md07 (webmail-md07.webmail.aol.com [64.12.170.145]) by cia-db02.mx.aol.com (v121.4) with ESMTP id MAILCIADB023-90a947c2f4a7228; Mon, 25 Feb 2008 12:02:31 -0500 References: To: flyrotary@lancaironline.net Subject: Re: [FlyRotary] Re: Water pressure Date: Mon, 25 Feb 2008 12:02:31 -0500 X-AOL-IP: 65.182.71.8 In-Reply-To: X-MB-Message-Source: WebUI MIME-Version: 1.0 From: bmears9413@aol.com X-MB-Message-Type: User Content-Type: multipart/alternative; boundary="--------MB_8CA45E75806057A_D3C_512C_webmail-md07.sysops.aol.com" X-Mailer: AOL Webmail 34032-STANDARD Received: from 65.182.71.8 by webmail-md07.sysops.aol.com (64.12.170.145) with HTTP (WebMailUI); Mon, 25 Feb 2008 12:02:31 -0500 Message-Id: <8CA45E75806057A-D3C-2828@webmail-md07.sysops.aol.com> X-Spam-Flag: NO ----------MB_8CA45E75806057A_D3C_512C_webmail-md07.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" I have the pressure cap right on the engine...no airspace. then if it overfl= ows it goes to a catch can, then sucks it back in when the engine cools. thi= s zero air is the reason for the pressure I'm sure.=20 Bob Mears -----Original Message----- From: Bill Bradburry To: Rotary motors in aircraft Sent: Mon, 25 Feb 2008 10:21 am Subject: [FlyRotary] Re: Water pressure Bob, how is your cooling system set up?=C2=A0 I was getting high water press= ures and blowing out of the overflow when I had a pressure cap on the radiat= or. I changed that to a radiator cap that has no pressure containment valve on t= he radiator, took the overflow hose from the radiator to the bottom of an ov= erflow bottle (a modified fire extinguisher)=C2=A0which has a 23# cap on it.= The overflow from this bottle vents to the outside, but so far, has never v= ented.=C2=A0 The bottle is about =C2=BE full of coolant.=C2=A0 This eliminat= ed my high pressures and stopped all the blowing out of the overflow.=C2=A0=20= I think that this is similar to the way most of the cooling systems are set=20= up on the list. =C2=A0 The air in the top of the overflow bottle prevents the hydraulic lock that E= d is talking about below, but ensures that there is no air in the circulatin= g coolant.=C2=A0 This didn=E2=80=99t solve all my cooling problems, but it e= liminated one of them.=C2=A0 :>) =C2=A0 Bill B =C2=A0 From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Beha= lf Of bmears9413@aol.com Sent: Monday, February 25, 2008 10:11 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Water pressure Cool deal...thanks guys. I have a 30lb. cap and havent let it get there yet=20= to see if it blows out to the overflow tank. I keep thinking that if I had a= regular automotive 15lb. cap it would already be pushing by that and its js= ut idleing. -----Original Message----- From: Ed Anderson To: Rotary motors in aircraft Sent: Mon, 25 Feb 2008 6:59 am Subject: [FlyRotary] Re: Water pressure Bob, if there is no air in your coolant system, you may be observing an hydr= aulic lock type phenomena.=C2=A0 My water pressure will immediately zoom to=20= 21 psi on engine start up.=C2=A0 As the engine warms up the pressure drops b= ack down.=C2=A0 My understanding is that with no air and the incompressible=20= nature of a liquid - that even small perturbations anywhere in the system ca= n cause the sensor to signal pressure.=C2=A0 As the engine warms and a very=20= small amount of expansion in block, rad cores, lines etc. happens that is en= ough increase in volume of the=C2=A0"containment" =C2=A0for the pressure to=20= lower. =C2=A0 This is why some folks recommend leaving a small amount of air under the cap= .=C2=A0 If you are not seeing oil in your coolant or bubbles then its unlike= ly you have a busted O ring. =C2=A0 Ed ----- Original Message -----=20 From: BMears9413@aol.com=20 To: Rotary motors in aircraft=20 Sent: Sunday, February 24, 2008 11:52 PM Subject: [FlyRotary] Water pressure =C2=A0 I ran my 20B at idle, till about 160 degrees. My water pressure rose up to 2= 3 lbs. That seems excessive to me, but I've never watched water pressure bef= ore. I've bled the block a couple of times and I dont feel like I have an ai= r lock. Heat is even throughout the radiator. I was a bit worried about comp= ression leaking into the cooling chamber, but I'm not loosing any water, the= plugs aren't wet, and it starts flawlessly each time. Hot or cold. Recon I'= m all worried about nothing? =C2=A0 Bob Mears=20 Supermarine Spitfire Delicious ideas to please the pickiest eaters. Watch the video on AOL Living= . size=3D2 width=3D"100%" align=3Dcenter>=20 More new features than ever. Check out the new AOL Mail! ________________________________________________________________________ More new features than ever. Check out the new AOL Mail ! - http://webmail.= aol.com ----------MB_8CA45E75806057A_D3C_512C_webmail-md07.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="utf-8" I have the pressure cap right on the engine...no airspace. then if it overfl= ows it goes to a catch can, then sucks it back in when the engine cools. thi= s zero air is the reason for the pressure I'm sure.
Bob Mears


-----Original Message-----
From: Bill Bradburry <bbradburry@bellsouth.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Mon, 25 Feb 2008 10:21 am
Subject: [FlyRotary] Re: Water pressure

Bob, how is your cooling system set up?  I was get= ting high water pressures and blowing out of the overflow when I had a press= ure cap on the radiator.
I changed that to a radiator cap that has no pressure c= ontainment valve on the radiator, took the overflow hose from the radiator t= o the bottom of an overflow bottle (a modified fire extinguisher) which= has a 23# cap on it. The overflow from this bottle vents to the outside, bu= t so far, has never vented.  The bottle is about =C2=BE full of coolant= .  This eliminated my high pressures and stopped all the blowing out of= the overflow.  I think that this is similar to the way most of the coo= ling systems are set up on the list.
 
The air in the top of the overflow bottle prevents the=20= hydraulic lock that Ed is talking about below, but ensures that there is no=20= air in the circulating coolant.  This didn=E2=80=99t solve all my cooli= ng problems, but it eliminated one of them.  :>)
 
Bill B
 
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of bmears9413@aol.com
Sent: Monday, February 25, 2= 008 10:11 AM
To: Rotary motors in aircraf= t
Subject: [FlyRotary] Re: Wat= er pressure
Cool deal...thanks guys. I=20= have a 30lb. cap and havent let it get there yet to see if it blows out to t= he overflow tank. I keep thinking that if I had a regular automotive 15lb. c= ap it would already be pushing by that and its jsut idleing.


-----Original Message-----
From: Ed Anderson <eanderson= @carolina.rr.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Mon, 25 Feb 2008 6:59 am
Subject: [FlyRotary] Re: Water pressure
Bob, if there is no air in your coolant system, you may= be observing an hydraulic lock type phenomena.  My water pressure will= immediately zoom to 21 psi on engine start up.  As the engine warms up= the pressure drops back down.  My understanding is that with no air an= d the incompressible nature of a liquid - that even small perturbations anyw= here in the system can cause the sensor to signal pressure.  As the eng= ine warms and a very small amount of expansion in block, rad cores, lines et= c. happens that is enough increase in volume of the "containment"  = ;for the pressure to lower.
 
This is why some folks recommend leaving a small amount= of air under the cap.  If you are not seeing oil in your coolant or bu= bbles then its unlikely you have a busted O ring.
 
Ed
----- Original Message -----
To: <= A title=3Dflyrotary@lancaironline.net href=3D"mailto:flyrotary@lancaironline= .net">Rotary motors in aircraft
Sent:= Sunday, February 24, 2008 11:52 PM
Subject:<= FONT face=3DArial size=3D2> [FlyRotary] Water pressure
 
I=20= ran my 20B at idle, till about 160 degrees. My water pressure rose up to 23=20= lbs. That seems excessive to me, but I've never watched water pressure befor= e. I've bled the block a couple of times and I dont feel like I have an air=20= lock. Heat is even throughout the radiator. I was a bit worried about compre= ssion leaking into the cooling chamber, but I'm not loosing any water, the p= lugs aren't wet, and it starts flawlessly each time. Hot or cold. Recon I'm=20= all worried about nothing?
 <= /div>
Bob Mears
Supermarine Spitfire<= /SPAN>


Delicious ideas to please the pickiest eaters. Watch the video on AOL Living.
size=3D2 width=3D"100%" align=3Dcenter>
More new features than ever.=20= Check out the new AOL Mail!
More new features than ever. Check out the new AOL Mail!
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