X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from outbound-mail.dca.untd.com ([64.136.47.15] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with SMTP id 2371220 for flyrotary@lancaironline.net; Fri, 05 Oct 2007 16:51:54 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.136.47.15; envelope-from=alwick@juno.com Received: from Penny (71-32-247-85.ptld.qwest.net [71.32.247.85]) by smtpout02.dca.untd.com with SMTP id AABDSPJ6QAVNSPJ2 for (sender ); Fri, 5 Oct 2007 13:50:22 -0700 (PDT) Message-ID: <07AD4AF1EA3D4D22AE8E3D5A62FF177A@Penny> From: "Al Wick" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: Coolant Water Pressure Date: Fri, 5 Oct 2007 13:50:20 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0143_01C80756.ABB3D350" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6000.16480 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16480 X-ContentStamp: 94:47:2387325352 X-MAIL-INFO:3e747471e5f07515bd690c71610c21d590ad800ce4c5559de5e480ade445e4e0603551107405710171a0e5c021b52dc015f0003514d1f994d4dd6dd4143444342de13d796da9951d79e191f591dd6495b0913451102910ad5980ad29746029c0f0e51df4a43444bd84d1cd34d0b9e4656541641955b151fd604d9051c07474ed90e069f0e904ad042540cd8401d9c02dbd1500118181b94904f5454d40f50cd05489f4118954f9f0744d8de1dd1d91509550d5e92439a4b579f9d0d4d4d19934ddc06d1455c9318da5d47d10b96d9db464ad1910b1559005f099509dc0e0e919e9698d75e0e580e9d92121d5bd69e5042d1d1581b1 X-UNTD-OriginStamp: L941HVjjYzDhN3itp//mkHzFQBwZF38JJgA4effAXAB8VrwsAYZfyg== X-UNTD-Peer-Info: 10.171.42.32|smtpout02.dca.untd.com|smtpout02.dca.untd.com|alwick@juno.com This is a multi-part message in MIME format. ------=_NextPart_000_0143_01C80756.ABB3D350 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Occasionally, when experimenting, you encounter a solution that has far = reaching positive effects. This dynamic air bleed is one of those. = Pretend we have 100 planes with dynamic bleed, and 100 without. We would = find greater incidence of overheated engines in the ones without. More = compression seal failures, more pinging, more flights with low coolant = level, etc etc. Your description of effects you experienced makes this = clear....along with all my years of measuring effects, testing concepts. I think it's hard to appreciate just how significant this is, because = it's easy to get by, or just react to the problem by taking it thru = extra cooling cycles. Since we don't measure how effective a solution = is, we never realize a slight change can dramatically improve safety. So = "ok" solutions get transferred from plane to plane, when a "knock your = socks off" solution gets overlooked. On my first engine install, I did a bunch of things that were dumb in = hind sight. I had a custom radiator made with the radiator hose location = 2" below the top of radiator. Hello! That meant I had 2" of air in = radiator. So I had them install fitting on top that allowed me to add = 1/4" hose up to filler neck. Dynamic air bleed. With my new engine = install, I have no extra hoses anywhere. It's guaranteed to work, and I = can prove it all out before ever flying.=20 I replied to your post, but my focus is on the guy that's designing his = cooling system now and in the future. If he just pretends coolant = doesn't flow....and considers how air will exit each component....he'll = have safer system. Ed, you do much better job than I do of combining = theoretical and measurement. I really like your btu calculations leading = to diagnosing cause for high temps. That's good stuff. Valuable. To some = extent my post takes advantage of your open mindedness. Sorry, I don't = intend to pick on you. Just trying to save a crash, or overheat, or = whatever. If you view every failure as a system failure (not operator), you will = find significant solutions. Good systems are insensitive to operator = errors. The dynamic bleed is a good example. I add coolant, it fills = right up. No trying to coerce coolant. No topping it off. Less prone to = operator goof ups. Most aircraft crashes have operator error as major = component. Same is true for manufacturing businesses. If you make most = of the systems insensitive to operator, then he is allowed to focus on = those few items that don't have system solutions. Operator makes fewer = mistakes. That's one of the key items I discovered as QA manager. It's = what I've done on my plane. regards -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 ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Friday, October 05, 2007 10:48 AM Subject: [FlyRotary] Re: Coolant Water Pressure You are absolutely correct, Al. Just did not think, gas/air = compresses, liquids do not (to any appreciable amount).=20 If by failure, you mean my system would not have supported flight in = that condition (air in coolant) , then you are quite correct, on the = other hand, one of the reasons to test (as you have often pointed out) = is to discover problems before flight inorder to preclude failures in = the air. In this case, I discovered my configuration requires a bit = more effort to remove the air. Once that is done, the system is = operating within its intended parameters. So does that make the = overheating a system failure or a failure to configure the system to = the proper operating parameters.=20 Even in the automobile, the rotary is known for trapping air and = requiring burping although many can get away without it because most = autos don't operate anywhere near WOT for more than a few seconds, so = the effects of trapped air (depending on amount) may not be noticed.=20 I think there is a difference, for instance you could design the = perfect coolant system but fail to put sufficient coolant into the = system resulting in overheating - is that a system failure or a = operational failure? or perhaps more accurately - operator failure? =20 I am always impressed by your meticulous attention to detail and = systematic approach. I could certainly have benefit from your = knowledge/approach back 10 years ago in my initial design{:>). But at = that time, there appear to be bigger issues - such as trying to = understand how a rotary engine really worked - sorted out. Air flow = and cooling were just vague notions back then and I just assume they = would naturally fall into place {:>) I still have a photo of my first oil cooler installation to remind me = of how ignorant of those matters, I was back then . It had a "Plenum" = that conformed to the area of the core - and its wall stood 2" way from = the core face at every point. Then I had a 2 1/2" dia hose piping air = to one corner. Is there small wonder that my first flight was limited = to once around the pattern due to oil temps{:>). Here is a photo - the = oil cooler plenum and inlet are the brown colored box on the left side = of the engine (facing the engine) close to the firewall with the large = back hose (that one is 5" in dia as one of my several early attempts to = address the oil temp problems). The radiator plenums were only slightly = better. =20 No question, knowing what I now know, I would have done some things = different. As you know, Al, I may sometimes take issue with your = characterization, but not your approach and insight. A valuable = contribution to say the least. Best Regards Ed ----- Original Message -----=20 From: Al Wick=20 To: Rotary motors in aircraft=20 Sent: Friday, October 05, 2007 12:49 PM Subject: [FlyRotary] Re: Coolant Water Pressure >at 22 psi the air would likely occupy even more space The opposite is true. Air space reduces substantially when you = increase pressure. Think of coolant as a solid, and air as a giant = spring. When you add btu's to coolant, it immediately responds by = expanding. This causes the air molecules to compress...a lot. There are some fun exhibits at the science museum I volunteer at we = use to demonstrate air/ water compression. An eye dropper inside a pop = bottle. When you squeeze the pop bottle, the eye dropper plummets to the = bottom. When you let go, dropper rises to surface. The pressure increase = when you squeeze bottle causes air in dropper to compress(less air = volume). This allows water to displace that air....dropper is now = heavier and falls to bottom.=20 It's really ironic. You can design a system that seems to work fine. = You fly with that for years with no failures( well I guess you could = call the pinging and high temps a failure). But a small change can = greatly reduce your risk. There's a lot of value to changing your air = bleed design to one that dynamically removes air. No shrader valve, no = repeated cooling cycles to remove air. By "dynamic" I mean that it = automatically removes air from the system. No muss no fuss.=20 As you design system, just pretend their is air at the top of each = component. Then find simple way to allow that air to move to higher = component in system. So, my radiator is lowest point in system. If I = place my radiator tube near the top of radiator, then all air naturally = leaves rad and flows to engine. Next I look at highest coolant passage = in engine. In my case I had to drill and tap a little 1/4 npt into the = coolant manifold, then run tube from there up to highest point in = system. Suddenly I've got a system that automatically removes all air = immediately. Try as I can, I can no longer trap air anywhere. If I = develop compression leak that pumps air into system, it has much less = effect, because it rises out of the coolant flow. When I drain and = refill, it all immediately and rapidly fills, I can get every drop back = into the system. Dynamic air bleed is a safety advantage, easy to accomplish. Each of = these safety advantages adds up mathematically.=20 Likewise, contrary to popular theory, leaving two cups of air under = cap increases safety. You can prove that to yourself with simple = experiment I described earlier.=20 -al wick ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Friday, October 05, 2007 9:07 AM Subject: [FlyRotary] Re: Coolant Water Pressure Yes, at 22 psi the air would likely occupy even more space, but = since I do my runup with the cap off or loose, there is no pressure = during the process. So while I have never measured it and it probably = varies from one time to the next, there appears to be approx 1/3 of the = top part of each core which has air on the initial fire up of the engine = - after a complete drain and refill of the coolant system. =20 I must admit that the first several times of draining and = refilling coolant, not being as knowledgeable as I am now, I almost = cooked the engine, because I assumed that when the header tank was full = - the engine had all the coolant it could take. Rapidly climbing = coolant temps and pinging of hot engine cooling off soon make it clear = that just because the header tank was full didn't mean a whole lot. Of = course, I noticed after each run up that the coolant level in the header = tank would decrease permitting me to put more coolant in. That finally = made me realize what the problem was - would have been very nice to have = this list around back then {:>) After burping the system there is still small amount of air left, = but the overflow tank set gradually removes the remaining air over a = couple of flights. Then the hydraulic "lock" phenomena starts with = initial pressure of 21-22 psi immediately on engine start, dropping off = quickly to zero and then gradually climbing back to 5 - 7 psi as the = coolant heats up. But, other than having to "clear" the air out with a couple/three = run ups to 5000 rpm, it works just fine and has since 97. I = occasionally toy with the idea of putting in simple small air bleed on = the top of each - but, like I said, it works fine and other things to do = {:>) Sounds like your approach will avoid my burping problem. However, = Lynn has mentioned that even in the car installation it often takes = burping the engine to get the air out. Ed ----- Original Message -----=20 From: Thomas Jakits=20 To: Rotary motors in aircraft=20 Sent: Friday, October 05, 2007 11:12 AM Subject: [FlyRotary] Re: Problem? [FlyRotary] Re: Coolant Water = Pressure Hi Ed, for sure I saw your installation before (numerous times...), but = I do not recall your exact pluming. Your description below sounds like inlet and outlet are facing = down. At 22psi it should even be more like 1/2 the radiator with air = :) Anyway, I assume waterflow is radical enough to strip the air = out in 3 trials. My system will have a bottom inlet and a top outlet. If it = doesn't fit the outlet may exit the bottom of the tank but will have an = internal standpipe - this way there is next to no space where air can = get trapped, just a small bubble atop the standpipe, won't be big enough = to cause any cooling detriment.=20 I still see BMW motorcycle oil-coolers mounted this way. Don't = know the exact make-up today, but the earliest ones where simple single = pass bottom feed bottom exit (cheapest solution and esthetically least = disturbing), a big problem to purge. 1/4 was useless because of trapped = air...=20 Furthermore, if the pump had a little leak or just a long time = between runs would drain the oil fro mthe cooler and at start-up you had = a fresh load of cold air inthe cooler! As it heats up the air-bubble = expands and reduces cooler volume even more...=20 Best Regards, TJ snipped.. In my case, if I do a complete drain and refill of the = system, on the first run up the core's tanks will be hot approx 2/3 of = the way up and then they are much cooler - indicating that the remaining = 1/3 of my core is filled with air. It generally takes me 3 runups = reaching 5000 rpm before I can touch the core tanks and find them hot = all the way from top to bottom. So depending on your radiator set up = that might be something you can quickly check.=20 snipped.... -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 -------------------------------------------------------------------------= ----- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html -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 ------=_NextPart_000_0143_01C80756.ABB3D350 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Occasionally, when experimenting, you = encounter a=20 solution that has far reaching positive effects. This dynamic air bleed = is one=20 of those. Pretend we have 100 planes with dynamic bleed, and 100 = without.=20 We would find greater incidence of overheated engines in the ones = without. More=20 compression seal failures, more pinging, more flights with low coolant = level,=20 etc etc. Your description of effects you experienced makes this = clear....along=20 with all my years of measuring effects, testing concepts.
 
I think it's hard to appreciate just = how=20 significant this is, because it's easy to get by, or just react to the = problem=20 by taking it thru extra cooling cycles. Since we don't measure how = effective a=20 solution is, we never realize a slight change can dramatically improve = safety.=20 So "ok" solutions get transferred from plane to plane, when a "knock = your socks=20 off" solution gets overlooked.
 
On my first engine install, I did a = bunch of things=20 that were dumb in hind sight. I had a custom radiator made with the = radiator=20 hose location 2" below the top of radiator. Hello! That meant I had 2" = of air in=20 radiator. So I had them install fitting on top that allowed me to add = 1/4" hose=20 up to filler neck. Dynamic air bleed. With my new engine install, I have = no=20 extra hoses anywhere. It's guaranteed to work, and I can prove it all = out before=20 ever flying.
 
I replied to your post, but my focus is = on the guy=20 that's designing his cooling system now and in the future. If he just = pretends=20 coolant doesn't flow....and considers how air will exit each = component....he'll=20 have safer system. Ed, you do much better job than I do of combining = theoretical=20 and measurement. I really like your btu calculations leading to = diagnosing cause=20 for high temps. That's good stuff. Valuable. To some extent my = post takes=20 advantage of your open mindedness. Sorry, I don't intend to pick on = you.=20 Just trying to save a crash, or overheat, or whatever.
 
If you view every failure as a system = failure (not=20 operator), you will find significant solutions. Good systems are = insensitive to=20 operator errors. The dynamic bleed is a good example. I add coolant, it = fills=20 right up. No trying to coerce coolant. No topping it off. Less prone to = operator=20 goof ups. Most aircraft crashes have operator error as major component. = Same is=20 true for manufacturing businesses. If you make most of the systems = insensitive=20 to operator, then he is allowed to focus on those few items that don't = have=20 system solutions. Operator makes fewer mistakes. That's one of the key = items I=20 discovered as QA manager. It's what I've done on my plane.
 
regards
 
-Al Wick
Cozy IV powered by Turbo = Subaru 3.0R=20 with variable valve lift and cam timing.
Artificial intelligence in = cockpit,=20 N9032U 240+ hours from Portland, Oregon
Glass panel design, Subaru = install,=20 Prop construct, Risk assessment info:
htt= p://www.maddyhome.com/canardpages/pages/alwick/index.html
 
 
 
----- Original Message -----
From:=20 Ed=20 Anderson
Sent: Friday, October 05, 2007 = 10:48=20 AM
Subject: [FlyRotary] Re: = Coolant Water=20 Pressure

You are absolutely correct, Al.  Just did = not=20 think, gas/air compresses, liquids do not (to any appreciable=20 amount). 
 
  If by failure, you mean my system would = not have=20 supported flight in that condition (air in coolant) , then you are = quite=20 correct, on the other hand, one of the reasons to test (as you have = often=20 pointed out) is to discover problems before flight inorder to preclude = failures in the air.  In this case, I discovered my configuration = requires a bit more effort to remove the air.  Once that is done, = the=20 system is operating within its intended parameters.  So does that = make=20 the overheating  a system failure or a failure to configure the = system to=20 the proper operating parameters. 
 
Even in the automobile, the rotary is known = for trapping=20 air and requiring burping although many can get away without it = because most=20 autos don't operate anywhere near WOT for more than a few seconds, so = the=20 effects of trapped air (depending on amount) may  not be=20 noticed. 
 
   I think there is a difference, = for instance=20 you could design the perfect coolant system but fail to put sufficient = coolant=20 into the system resulting in overheating - is that a system failure or = a=20 operational failure? or perhaps more accurately - operator = failure? =20
 
I am always  impressed by your meticulous = attention=20 to detail and systematic approach.  I  could certainly have = benefit=20 from your knowledge/approach  back 10 years ago in my initial=20 design{:>).  But at that time, there appear to be bigger = issues - such=20 as trying to understand how  a rotary engine really = worked=20 - sorted out.  Air flow and cooling were just vague = notions=20 back then and I just assume they would naturally fall into place=20 {:>)
 
 I still have a photo of my first oil = cooler=20 installation to remind me of how ignorant of those matters,  I = was back=20 then .  It had a "Plenum" that conformed to the area of the core = - and=20 its wall stood 2" way from the core face at every point.  Then I = had a 2=20 1/2" dia hose piping air to one corner.  Is there small wonder = that my=20 first flight was limited to once around the pattern due to oil=20 temps{:>).  Here is a photo - the oil cooler plenum and inlet = are the=20 brown colored box on the left side of the engine (facing the engine) = close to=20 the firewall with the large back hose (that one is 5" in dia as one of = my=20 several  early attempts to address the oil temp problems).  = The=20 radiator plenums were only slightly better.  
 
No question, knowing what I now know, I = would=20 have done some things different.   As you know, Al, =  I may=20 sometimes take issue with your characterization, but not your approach = and=20 insight.  A valuable contribution to say the least.
 
Best Regards
 
Ed
----- Original Message -----
From:=20 Al = Wick
To: Rotary motors in = aircraft=20
Sent: Friday, October 05, = 2007 12:49=20 PM
Subject: [FlyRotary] Re: = Coolant Water=20 Pressure

>at 22 psi the air would likely occupy = even more=20 space
 
The opposite is true. Air space reduces = substantially=20 when you increase pressure. Think of coolant as a solid, and = air as a=20 giant spring. When you add btu's to coolant, it immediately responds = by=20 expanding. This causes the air molecules to compress...a = lot.
 
There are some fun exhibits at the science = museum I=20 volunteer at we use to demonstrate air/ water compression. An eye = dropper=20 inside a pop bottle. When you squeeze the pop bottle, the eye = dropper=20 plummets to the bottom. When you let go, dropper rises to surface. = The=20 pressure increase when you squeeze bottle causes air in dropper to=20 compress(less air volume). This allows water to displace that = air....dropper=20 is now heavier and falls to bottom.
 
It's really ironic. You can design a system = that seems=20 to work fine. You fly with that for years with no failures( well I = guess you=20 could call the pinging and high temps a failure). But a small change = can=20 greatly reduce your risk. There's a lot of value to changing your = air bleed=20 design to one that dynamically removes air. No shrader valve, no = repeated=20 cooling cycles to remove air. By "dynamic" I mean that it = automatically=20 removes air from the system. No muss no fuss.
 
As you design system, just pretend their is = air at the=20 top of each component. Then find simple way to allow that air to = move to=20 higher component in system. So, my radiator is lowest point in = system. If I=20 place my radiator tube near the top of radiator, then all air = naturally=20 leaves rad and flows to engine. Next I look at highest coolant = passage in=20 engine. In my case I had to drill and tap a little 1/4 npt into the = coolant=20 manifold, then run tube from there up to highest point in system. = Suddenly=20 I've got a system that automatically removes all air immediately. = Try as I=20 can, I can no longer trap air anywhere. If I develop compression = leak that=20 pumps air into system, it has much less effect, because it rises out = of the=20 coolant flow. When I drain and refill, it all immediately and = rapidly fills,=20 I can get every drop back into the system.
 
Dynamic air bleed is a safety = advantage, easy to=20 accomplish. Each of these safety advantages adds up mathematically.=20
Likewise, contrary to popular theory, = leaving two cups=20 of air under cap increases safety. You can prove that to yourself = with=20 simple experiment I described earlier.
 
-al wick
 
----- Original Message ----- =
From:=20 Ed Anderson
To: Rotary motors in = aircraft=20
Sent: Friday, October 05, = 2007 9:07=20 AM
Subject: [FlyRotary] Re: = Coolant=20 Water Pressure

 
Yes, at 22 psi the air would likely occupy = even more=20 space, but since I do my runup with the cap off or loose, there is = no=20 pressure during the process.  So while I have never measured = it and=20 it probably varies from one time to the next, there appears to be = approx=20 1/3 of the top part of each core which has air on the initial fire = up of=20 the engine - after a complete drain and refill of the coolant=20 system. 
 
I must admit that the first several times = of=20 draining and refilling coolant, not being as knowledgeable as I am = now, I=20 almost cooked the engine, because I assumed that when the header = tank was=20 full - the engine had all the coolant it could take.  Rapidly = climbing coolant temps and pinging of hot engine cooling off soon = make it=20 clear that just because the header tank was full didn't mean a = whole=20 lot.  Of course, I noticed after each run up that the coolant = level=20 in the header tank would decrease permitting me to put more = coolant=20 in.  That finally made me realize what the problem was - = would have=20 been very nice to have this list around back then = {:>)
 
 
 
After burping the system there is still = small amount=20 of air left, but the overflow tank set gradually removes the = remaining air=20 over a couple of flights.  Then the hydraulic "lock" = phenomena starts=20 with initial pressure of 21-22 psi immediately on engine start, = dropping=20 off  quickly to zero and then gradually climbing  back = to 5 - 7=20 psi as the coolant heats  up.
 
 
But, other than having to "clear" the air = out with a=20 couple/three run ups to 5000 rpm, it works just fine and has since = 97.  I occasionally toy with the idea of putting in simple = small air=20 bleed on the top of each - but, like I said, it works fine and = other=20 things to do {:>)
 
Sounds like your approach will avoid my = burping=20 problem.  However, Lynn has mentioned that even in the car=20 installation it often takes burping the engine to get the air=20 out.
 
Ed
----- Original Message ----- =
From:=20 Thomas Jakits =
To: Rotary motors in = aircraft=20
Sent: Friday, October 05, = 2007=20 11:12 AM
Subject: [FlyRotary] Re: = Problem?=20 [FlyRotary] Re: Coolant Water Pressure

Hi Ed,
 
for sure I saw your installation before (numerous = times...), but I=20 do not recall your exact pluming.
Your description below sounds like inlet and outlet are = facing=20 down.
At 22psi it should even be more like 1/2 the radiator with = air=20 :)
Anyway, I assume waterflow is radical enough to strip the = air out=20 in 3 trials.
My system will have a bottom inlet and a top outlet. If it = doesn't=20 fit the outlet may exit the bottom of the tank but will have an = internal=20 standpipe - this way there is next to no space where air can get = trapped, just a small bubble atop the standpipe, won't be big = enough to=20 cause any cooling detriment.
I still see BMW motorcycle oil-coolers mounted this way. = Don't know=20 the exact make-up today, but the earliest ones where simple = single pass=20 bottom feed bottom exit (cheapest solution and esthetically = least=20 disturbing), a big problem to purge. 1/4 was useless because of = trapped=20 air...
Furthermore, if the pump had a little leak or just a long = time=20 between runs would drain the oil fro mthe cooler and at start-up = you had=20 a fresh load of cold air inthe cooler! As it heats up the = air-bubble=20 expands and reduces cooler volume even more...
 
Best Regards,
 
TJ

snipped..
 In my case, if I do a = complete drain=20 and refill of the system, on the first run up the core's tanks =  will be hot approx 2/3 of the way up and then they are = much=20 cooler - indicating that the remaining 1/3 of my core is = filled with=20 air.  It generally takes me 3 runups reaching 5000 = rpm=20 before I can touch  the core tanks and find them hot = all the=20 way from top to bottom.  So depending on your radiator = set up=20 that might be something you can quickly check.=20
 
 
snipped....

=
 
-Al Wick
Cozy IV powered by Turbo Subaru 3.0R with variable = valve=20 lift and cam timing.
Artificial intelligence in cockpit, N9032U = 240+=20 hours from Portland, Oregon
Glass panel design, Subaru install, = Prop=20 construct, Risk assessment info:
htt= p://www.maddyhome.com/canardpages/pages/alwick/index.html

--
Homepage:  http://www.flyrotary.com/
Archive and=20 UnSub:  =20 = http://mail.lancaironline.net:81/lists/flyrotary/List.html
-Al Wick
Cozy IV powered by Turbo Subaru 3.0R with variable = valve lift=20 and cam timing.
Artificial intelligence in cockpit, N9032U 240+ = hours from=20 Portland, Oregon
Glass panel design, Subaru install, Prop construct, = Risk=20 assessment info:
htt= p://www.maddyhome.com/canardpages/pages/alwick/index.html
------=_NextPart_000_0143_01C80756.ABB3D350--