X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost03.isp.att.net ([204.127.217.103] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3844708 for flyrotary@lancaironline.net; Thu, 10 Sep 2009 14:43:20 -0400 Received-SPF: none receiver=logan.com; client-ip=204.127.217.103; envelope-from=keltro@att.net DKIM-Signature: v=1; q=dns/txt; d=att.net; s=dkim01; i=keltro@att.net; a=rsa-sha256; c=relaxed/relaxed; t=1252608202; h=Content-Type: MIME-Version:In-Reply-To:Message-Id:Date:Subject:To:From; bh=CbXg1D Ik+l9iMWAReK8Of42n6uJxFAtRAAy8ctji7Yc=; b=B3ulG37m58Tw85nHFvGxmvaI5 CTmtgMvrMm76Hz690hi2PRmI0RAUkl9INgbT1dYwnWJjzUgrbPZ8vmKIICOQw== Received: from fwebmail06.isp.att.net ([207.115.11.156]) by isp.att.net (frfwmhc03) with SMTP id <20090910184246H0300pphqae>; Thu, 10 Sep 2009 18:42:46 +0000 X-Originating-IP: [207.115.11.156] Received: from [208.114.32.156] by fwebmail06.isp.att.net; Thu, 10 Sep 2009 18:42:46 +0000 From: "Kelly Troyer" To: "Rotary motors in aircraft" Subject: cooling plumbing design [ right?, right? :-) ] Date: Thu, 10 Sep 2009 18:42:46 +0000 Message-Id: <091020091842.8053.4AA948A5000BB0DC00001F7522230682329B0A02D29B9B0EBF019D9B040A05@att.net> In-Reply-To: X-Mailer: AT&T Message Center Version 1 (Mar 2 2009) X-Authenticated-Sender: a2VsdHJvQGF0dC5uZXQ= MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="NextPart_Webmail_9m3u9jl4l_8053_1252608166_0" --NextPart_Webmail_9m3u9jl4l_8053_1252608166_0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Guys, We have two schools of thought going in this discussion and have had for= some time..........One=20 opinion has the bottom of the expansion tank plumbed to the "Outlet" of the= pump (as Tracy does & others)..........The other has the bottom of the expansion tank plumbed to = the "Inlet" of the pump (as Al G., Mark S. & others do)..........I believe the inlet position came = from the "Stewart Racing Pump" site...........The rational being that this was the lowest pressure s= ite of the cooling system and would not subject the system pressure "Cap" (on the expansion tank) to bot= h system and pumping pressure..............Take your choice as both methods work and are flying = successfully..........I just wanted to point out this difference and remove confusion...........=20 -- Kelly Troyer=20 "Dyke Delta"_13B ROTARY Engine=20 "RWS"_RD1C/EC2/EM2=20 "Mistral"_Backplate/Oil Manifold=20 -------------- Original message from Tracy Crook = : --------------=20 Re-reading Kevin's post I'm not sure I understood it the first time. In fa= ct, the more I read it the more confused I get : ) Maybe this will fill in the blanks. The pressure at the port in question i= s dynamic pressure due to the water pump, not expansion. It might suck som= e air on cool down when the engine is shut off but will immediately flush i= t out on startup. The other point is the bottom port of expansion tank sho= uld go to the top (outlet) of the pump housing, not the inlet. Therefore t= here is no bypassing of the radiator. Tracy On Thu, Sep 10, 2009 at 9:31 AM, Tracy Crook wro= te: As Ayn Rand said, "There are no contradictions. If you see one, examine = your premise." Why would you want a large flow through the expansion tank? Tracy=20 On Thu, Sep 10, 2009 at 2:02 AM, kevin lane wrote: I was embarrassed to ask about this originally, but it seems I am not alone= with questions. having viewed several flying cooling system flow designs = at the rotary round-up, perhaps it isn't that critical. one aspect I trying to understand is the expansion tank. there shouldn't= a big flow thru there, right? if the pressure is greatest at this far rot= or housing top port, then it must be lower in the expansion tank, and a slo= w flow will take place towards the expansion tank, right? the small diamet= er line will tend to push bubbles thru and they will separate in the expans= ion tank. so, if they enter the tank above water level, this line will suck= air from the expansion tank as the cooling fluid cools and has a lesser vo= lume, right? not good. if the expansion tank feeds the cooling circulatio= n system by T'ing into the water pump output, then it is all on the higher = pressure side of the system, and the air in the expansion tank won't have a= tendency to be sucked into the circulation? is the design intention to ke= ep the expansion tank under pressure, rather than have it part of the flow = [circulation]? if the expansion tank was plumbed into the water pump inl= et port, then a second circulation route is created, which doesn't involved= the radiator [rear rotor port to tank to water pump, thru engine block to = rear port....], right? as far as the bubble line for the radiator it seems that it would work by a= llowing trapped bubbles in the higher end of the radiator to travel uphill = to the expansion tank. is the pressure at the radiator also higher, as wit= h the rear port? enough questions. clear as mud, right? kevin --NextPart_Webmail_9m3u9jl4l_8053_1252608166_0 Content-Type: multipart/related; boundary="NextPart_Webmail_9m3u9jl4l_8053_1252608166_1" --NextPart_Webmail_9m3u9jl4l_8053_1252608166_1 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable
Guys,
   We have two schools of thought going in this discussion a= nd have had for some time..........One
opinion has the bottom of the expansion tank plumbed to the "Outlet" o= f the pump (as Tracy does &
others)..........The other has the bottom of the expansion tank plumbe= d to the "Inlet" of the pump
(as Al G., Mark S. & others do)..........I believe the inlet posit= ion came from the "Stewart Racing
Pump" site...........The rational being that this was the lowest press= ure site of the cooling system and
would not subject the system pressure "Cap"  (on the expansion ta= nk) to both system and pumping
pressure..............Take your choice as both methods work and are fl= ying successfully..........I just
wanted to point out this difference and remove confusion...........&nb= sp;
--
Kelly Troyer
"Dyke Delta"_1= 3B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifol= d



 
-------------- Original message from Tracy Crook <tracy@r= otaryaviation.com>: --------------

Re-reading Kevin's post I'm n= ot sure I understood it the first time.  In fact, the more I read it t= he more confused I get : )

Maybe this will fill in the blanks. = The pressure at the port in question is dynamic pressure due to the water = pump, not expansion.  It might suck some air on cool down when the eng= ine is shut off but will immediately flush it out on startup.  The oth= er point is the bottom port of expansion tank should go to the top (outlet)= of the pump housing, not the inlet.  Therefore there is no bypassing = of the radiator.

Tracy

On Thu, Sep 10, 2009 at 9:31 AM, Tracy Crook <tracy@rotaryavia= tion.com> wrote:
As Ayn Rand said, &nbs= p; "There are no contradictions.  If you see one, examine your premise= ."

Why would you want a large flow through the expansion tank?
Tracy

On Thu, Sep 10, 2009 at 2:02 AM, kevin lane <n3773@co= mcast.net> wrote:
I was embarrassed to ask about this origi= nally, but it seems I am not alone with questions.  having viewed seve= ral flying cooling system flow designs at the rotary round-up, perhaps it i= sn't that critical.
  one aspect I trying to understand = is the expansion tank.  there shouldn't a big flow thru there, right?&= nbsp; if the pressure is greatest at this far rotor housing top port, then = it must be lower in the expansion tank, and a slow flow will take place tow= ards the expansion tank, right?  the small diameter line will ten= d to push bubbles thru and they will separate in the expansion tank. s= o, if they enter the tank above water level, this line will suck air f= rom the expansion tank as the cooling fluid cools and has a lesser volume, = right? not good.   if the expansion tank feeds the cooling circul= ation system by T'ing into the water pump output, then it is all on the hig= her pressure side of the system, and the air in the expansion tank won't ha= ve a tendency to be sucked into the circulation?  is the design intent= ion to keep the expansion tank under pressure, rather than have it part of = the flow [circulation]?    if the expansion tank was plumbed= into the water pump inlet port, then a second circulation route is created= , which doesn't involved the radiator [rear rotor port to tank to water pum= p, thru engine block to rear port....], right?
as far as the bubble line for the radiato= r it seems that it would work by allowing trapped bubbles in the higher end= of the radiator to travel uphill to the expansion tank.  is the press= ure at the radiator also higher, as with the rear port?
enough questions.  clear as mud, rig= ht?   kevin


--NextPart_Webmail_9m3u9jl4l_8053_1252608166_1-- --NextPart_Webmail_9m3u9jl4l_8053_1252608166_0--