X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 30 [X] Return-Path: Received: from smtp104.sbc.mail.mud.yahoo.com ([68.142.198.203] verified) by logan.com (CommuniGate Pro SMTP 5.1.7) with SMTP id 1931177 for flyrotary@lancaironline.net; Mon, 19 Mar 2007 18:20:19 -0400 Received-SPF: none receiver=logan.com; client-ip=68.142.198.203; envelope-from=dcarter11@sbcglobal.net Received: (qmail 6041 invoked from network); 19 Mar 2007 22:19:33 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=sbcglobal.net; h=Received:X-YMail-OSG:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=wU4M7CqibUaggmR6pC6O1xgI7BFEXXOSx+VG5nhNbvLQKUMgc0/x7Nb6vqJQYfM50IC9IhqrpbvachtxRw23mEQ0LdSAjwucaRpePJkdoPoLCKiRphdqFFjcgpBWZDPMGf8kazI45Jwkf1UWFrHx2Z019d+VldhZt2Bf9Cv/Q90= ; Received: from unknown (HELO davidsdell8200) (dcarter11@sbcglobal.net@70.136.27.61 with login) by smtp104.sbc.mail.mud.yahoo.com with SMTP; 19 Mar 2007 22:19:32 -0000 X-YMail-OSG: 7ntaN18VM1kTSFTilFWpmMuaxN6uqB.6QkTyRga4Mpp1YS4cGKMTINZ0j.fqMj6vnnLG3gXgc5FjuYFPsPFAN.KSzGZxMEN0shw5Smj3lIqPYUjSxcRaalc7mf9LcTlVypTNwM26DGmqip2HLVAjI2ZsNw-- Message-ID: <008001c76a74$aa4e7e90$6501a8c0@davidsdell8200> From: "David Carter" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: water boiling point Date: Mon, 19 Mar 2007 17:19:29 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_007D_01C76A4A.C0C5A150" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 This is a multi-part message in MIME format. ------=_NextPart_000_007D_01C76A4A.C0C5A150 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: [FlyRotary] water boiling pointAl has hit the nail on the head - in = my opinion. I don't even have my RX-8 mounted yet, much less have any personal = experience with the cooling system. But, I've been monitoring this list = for about 10 years and learning a LOT. . . .I have previously posted that I plan to use the Ford Contour (about = year model 2000) architecture - pressure coolant tank (fill system = through this tanks opening, which is then sealed with the only pressure = cap in the system), mounted so its coolant level (which allows air space = above the coolant, exactly as Al describes) about level with or slightly = higher than the highest point in the system (top of engine). At this = highest point, there is an "air" bleen (very small line) back directly = to the coolant tank (can't figure if it makes any difference if its = entrance into the tank is below or above the coolant level - think it = makes no difference). This purges steam and air, when/if any exists in = the system, so we have only liquid surrounding the engine. This cooling system is filled by pouring coolant into the tank - the = main line from tank into cooling system is a straight-down a large pipe = to a T at the bottom of the car's radiator, the lowest spot in the = system, so, as system fills with liquid, it forces air out the top, = eventually with fluid coming out the "air bleed" fitting mentioned above = and concurrently filling the "tank". No burping required. And there is = still an appropriate amount of air on top of the coolant in the tank. No one has ever found fault with this system as far as I've seen by = watcing this list - but also, no one has ever resonded to my posts = either saying , "Yeah, that's right" or "That is less than optimum = because . . . ". I'm not whining about not getting reinforcement or = validation. But I'm pointing out that it appears most folks flying so = far already have a non-optimum system installed and must not be ready to = comment about a system they don't use. I'd have thought someone would = have at least commented one way or the other. . . . But to the contrary, the "other" systems continue to seem to = proliferate and all kinds of different expansion tank locations and = construction get shared here. Nevertheless, I think Al has described the perfect system. David Carter RV-6 (still on canopy frame) ----- Original Message -----=20 From: al p wick=20 To: Rotary motors in aircraft=20 Sent: Monday, March 19, 2007 2:10 PM Subject: [FlyRotary] Re: water boiling point There's one coolant design that's substantially better than the = others. I discovered it when doing severe ground testing...deliberately = overheating my engine.=20 Three basic requirements: 1) Place your radiator cap and reservoir above engine. The higher the = better. This allows trapped air in system to rise out of the flow and = stay there.=20 2) Put a 24 psi cap on the system. You can throw away your overflow = stuff. Not needed. 3) Always keep around 2 cups of air under the cap. This is the key = item. It brings a big safety advantage. It allows you to use coolant = pressure to predict well in advance how good your system is doing. It = minimizes pressure. Mine never exceeds 7 psi. But if something goes = wrong, then my pressure rises and I gain boilover protection due to the = increase in system pressure.=20 If you have compression leak into the cooling system, it shows = immediately as spike in pressure that reaches 24psi. But when all is = normal, you never see pressure above 7 psi. If you have any cooling = problem, the pressure gage will respond quicker than any other sensor.=20 Sounds like many of you don't have that 2 cups of air. As result, your = coolant pressure regularly reaches 24 psi. Stressing components = (radiator welds actually). It masks compression leaks. Makes it = difficult to predict your safety margin. =20 Tough to explain this stuff in text, but it's a big improvement in = safety margin. No downside. To qualify the system, I omit the two cups of air. This causes = pressure to rise to 24 psi. Thus proving all of my welds and connections = have safety margin. Then I add the 2 cups of air and the system never = rises above 7 psi unless something goes wrong....whereupon I have extra = margin preventing boilover. Your biggest cooling risk as it cascades and = is nearly irreversible. =20 -al wick Cozy IV powered by Turbo Subaru 3.0R with variable valve lift and cam = timing.=20 Artificial intelligence in cockpit, N9032U 240+ hours from Portland, = Oregon Glass panel design, Subaru install, Prop construct, Risk assessment = info: http://www.maddyhome.com/canardpages/pages/alwick/index.html = =20 On Sun, 18 Mar 2007 11:41:33 -0400 "Tracy Crook" = writes: Higher coolant pressure will naturally increase the risk of a leak = due to blown hose, loose clamp, radiator tank failure, etc. As in many = of these matters, it is the builders choice as to which potential = problem is most important. =20 BTW, I do recommend doing a system pressure test at annual = inspection time or after making any changes. I intentionally = over-pressure the system by 50% by hooking a regulated air pressure = source to the overflow port on the cap fitting. I could be wrong but the likelihood of a blown rotor housing coolant = seal from coolant pressure is very low. If coolant pressure causes them = to leak there was a problem that needed to be addressed long before the = leak happened. Most coolant seal leaks happen at the inner seal which = normally have to seal combustion chamber pressure. Even 30 psi coolant = pressure is a very tiny fraction of that. Tracy (still waiting on Bluemountain) ------=_NextPart_000_007D_01C76A4A.C0C5A150 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: [FlyRotary] water boiling point
Al has hit the nail on the head - in my=20 opinion.
 
I don't even have my RX-8 mounted yet, much less = have any=20 personal experience with the cooling system.  But, I've been = monitoring=20 this list for about 10 years and learning a LOT.
. . .I have previously posted that I plan to use = the Ford=20 Contour (about year model 2000) architecture - pressure coolant tank = (fill=20 system through this tanks opening, which is then sealed with the only = pressure=20 cap in the system), mounted so its coolant level (which allows air space = above=20 the coolant, exactly as Al describes) about level with or slightly = higher than=20 the highest point in the system (top of engine).  At this highest = point,=20 there is an "air" bleen (very small line) back directly to the coolant = tank=20 (can't figure if it makes any difference if its entrance into the tank = is below=20 or above the coolant level - think it makes no difference).  This = purges=20 steam and air, when/if any exists in the system, so we have only liquid=20 surrounding the engine.
 
This cooling system is filled by pouring = coolant into=20 the tank - the main line from tank into cooling system is a = straight-down a=20 large pipe to a T at the bottom of the car's radiator, the lowest spot = in the=20 system, so, as system fills with liquid, it forces air out the top, = eventually=20 with fluid coming out the "air bleed" fitting mentioned above and = concurrently=20 filling the "tank".  No burping required.  And there is still = an=20 appropriate amount of air on top of the coolant in the = tank.
 
No one has ever found fault with this system as = far as=20 I've seen by watcing this list - but also, no one has ever resonded = to my=20 posts either saying , "Yeah, that's right" or "That is less than optimum = because=20 . . . ".  I'm not whining about not getting reinforcement or=20 validation.  But I'm pointing out that it appears most folks flying = so far=20 already have a non-optimum system installed and must not be ready to = comment=20 about a system they don't use.  I'd have thought someone would have = at=20 least commented one way or the other.
. . . But to the contrary, the "other" systems = continue to=20 seem to proliferate and all kinds of different expansion tank locations = and=20 construction get shared here.
 
Nevertheless, I think Al has described the = perfect=20 system.
 
David Carter
RV-6 (still on canopy frame)
----- Original Message -----
From:=20 al p = wick
Sent: Monday, March 19, 2007 = 2:10=20 PM
Subject: [FlyRotary] Re: water = boiling=20 point

There's one coolant design that's substantially better than the = others. I=20 discovered it when doing severe ground testing...deliberately = overheating my=20 engine.
 
Three basic requirements:
 
1) Place your radiator cap and reservoir above engine. The higher = the=20 better. This allows trapped air in system to rise out of the flow and = stay=20 there.
2) Put a 24 psi cap on the system. You can throw away your = overflow=20 stuff. Not needed.
3) Always keep around 2 cups of air under the cap. This is the = key item.=20 It brings a big safety advantage. It allows you to use coolant = pressure to=20 predict well in advance how good your system is doing. It minimizes = pressure.=20 Mine never exceeds 7 psi. But if something goes wrong, then my = pressure rises=20 and I gain boilover protection due to the increase in system pressure. =
 
If you have compression leak into the cooling system, it shows=20 immediately as spike in pressure that reaches 24psi. But when all is = normal,=20 you never see pressure above 7 psi. If you have any cooling problem, = the=20 pressure gage will respond quicker than any other sensor.
 
Sounds like many of you don't have that 2 cups of air. As = result,=20 your coolant pressure regularly reaches 24 psi. Stressing components = (radiator=20 welds actually). It masks compression leaks. Makes it difficult = to=20 predict your safety margin.  
 
Tough to explain this stuff in text, but it's a big = improvement in=20 safety margin. No downside.
 
To qualify the system, I omit the two cups of air. This causes = pressure=20 to rise to 24 psi. Thus proving all of my welds and connections have = safety=20 margin. Then I add the 2 cups of air and the system never rises = above 7=20 psi unless something goes wrong....whereupon I have extra margin = preventing=20 boilover. Your biggest cooling risk as it cascades and is = nearly=20 irreversible.  
 

-al wick
Cozy IV powered by Turbo Subaru 3.0R with = variable valve=20 lift and cam timing.
Artificial intelligence in cockpit, N9032U = 240+ hours=20 from Portland, Oregon
Glass panel design, Subaru install, Prop = construct,=20 Risk assessment info:
htt= p://www.maddyhome.com/canardpages/pages/alwick/index.html
 &n= bsp;           &nb= sp;           &nbs= p;            = ;            =             &= nbsp;           &n= bsp;           &nb= sp;           &nbs= p;            = ;      
 
On Sun, 18 Mar 2007 11:41:33 -0400 "Tracy Crook" <lors01@msn.com> writes:
Higher coolant pressure will naturally increase the risk of a = leak due=20 to blown hose, loose clamp, radiator tank failure, etc.  As in = many of=20 these matters, it is the builders choice as to which potential = problem is=20 most important.  
 
BTW, I do recommend doing a system pressure test at=20 annual inspection time or after making any changes.  I=20 intentionally over-pressure the system by 50% by hooking a regulated = air=20 pressure source to the overflow port on the cap fitting.
 
I could be wrong but the likelihood of a blown rotor housing = coolant=20 seal from coolant pressure is very low.  If coolant = pressure=20 causes them to leak there was a problem that needed to be addressed = long=20 before the leak happened.  Most coolant seal leaks happen at = the inner=20 seal which normally have to seal combustion chamber pressure.  = Even 30=20 psi coolant pressure is a very tiny fraction of that.
 
Tracy  (still waiting on=20 Bluemountain)
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