X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.121] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2371278 for flyrotary@lancaironline.net; Fri, 05 Oct 2007 17:32:24 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.121; envelope-from=eanderson@carolina.rr.com Received: from edward2 ([24.74.103.61]) by cdptpa-omta06.mail.rr.com with SMTP id <20071005213147.JZPC3972.cdptpa-omta06.mail.rr.com@edward2> for ; Fri, 5 Oct 2007 21:31:47 +0000 Message-ID: <000d01c80797$2aa10170$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Coolant Water Pressure Date: Fri, 5 Oct 2007 17:32:01 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000A_01C80775.A353DF10" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 This is a multi-part message in MIME format. ------=_NextPart_000_000A_01C80775.A353DF10 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable You make some excellent points, Al, even though I don't agree with = viewing every failure as a system failure. An operator failure can = screw even the best of system designs - so I believe we need to = segregate failures into those two categories. To attempt to make some = system fool proof (even if possible) can add to complexity, weight and = cost. So I personally think you are forced to make compromises in any = design - just a personal opinion, of course. =20 However, I understand your point - approach it from a systems viewpoint = to minimize( so much as feasible) as many factors that can cause a = failure as we can - because you'll certainly never redesign the operator = {:>). =20 You've presented a lot of good points over the years, Al. Have you = considered producing a guideline pamphlet with an overall approach to = some of these areas? =20 Also, I know you're not poking at me, Al. Just a starting point for the = discussion which hopefully will benefit somebody on the list. =20 Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.dmack.net/mazda/index.html . =20 =20 =20 ----- Original Message -----=20 From: Al Wick=20 To: Rotary motors in aircraft=20 Sent: Friday, October 05, 2007 4:50 PM Subject: [FlyRotary] Re: Coolant Water Pressure 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_000A_01C80775.A353DF10 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
You make some excellent points, Al, even = though I=20 don't agree with viewing every failure as a system failure.  An = operator=20 failure can screw even the best of system designs - so I believe we need = to=20 segregate failures into those two categories. To attempt to make = some=20 system  fool proof (even if possible) can add to complexity, weight = and=20 cost.  So I personally think you are forced to make compromises in = any=20 design - just a personal opinion, of = course.  
 
 However, I understand your point - = approach it from=20 a systems viewpoint to minimize( so much as feasible) as many factors = that can=20 cause a failure as we can - because you'll certainly never redesign the = operator=20 {:>). 
 
You've presented a lot of good points over the = years,=20 Al.  Have you considered producing a guideline pamphlet with an = overall=20 approach to some of these areas?
 
Also, I know you're not poking at me, Al.  = Just a=20 starting point for the discussion which hopefully will benefit somebody = on the=20 list. 
 
Ed
 
Ed Anderson
Rv-6A N494BW Rotary = Powered
Matthews,=20 NC
eanderson@carolina.rr.comhttp://www.andersonee.com
http:/= /members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.dmack.net/mazda= /index.html
 
. 
 
  
  
 
 
 
 ----- Original Message -----
From:=20 Al Wick =
Sent: Friday, October 05, 2007 = 4:50=20 PM
Subject: [FlyRotary] Re: = Coolant Water=20 Pressure

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.=20 More compression seal failures, more pinging, more flights with low = coolant=20 level, etc etc. Your description of effects you experienced makes this = clear....along with all my years of measuring effects, testing=20 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=20 socks off" solution gets overlooked.
 
On my first engine install, I did a = bunch of=20 things that were dumb in hind sight. I had a custom radiator made with = the=20 radiator hose location 2" below the top of radiator. Hello! That meant = I had=20 2" of air in radiator. So I had them install fitting on top that = allowed me to=20 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=20 prove it all out before ever flying.
 
I replied to your post, but my focus = is on the=20 guy that's designing his cooling system now and in the future. If he = just=20 pretends coolant doesn't flow....and considers how air will exit each=20 component....he'll have safer system. Ed, you do much better job than = I do of=20 combining theoretical and measurement. I really like your btu = calculations=20 leading to diagnosing cause for high temps. That's good stuff. = Valuable. To=20 some extent my post takes advantage of your open mindedness. = Sorry,=20 I don't intend to pick on you. Just trying to save a crash, or = overheat, or=20 whatever.
 
If you view every failure as a system = failure=20 (not operator), you will find significant solutions. Good systems are=20 insensitive to operator errors. The dynamic bleed is a good example. I = add=20 coolant, it fills right up. No trying to coerce coolant. No topping it = off.=20 Less prone to operator goof ups. Most aircraft crashes have operator = error as=20 major component. Same is true for manufacturing businesses. If you = make most=20 of the systems insensitive to operator, then he is allowed to focus on = those=20 few items that don't have system solutions. Operator makes fewer = mistakes.=20 That's one of the key items I discovered as QA manager. It's what I've = done on=20 my plane.
 
regards
 
-Al Wick
Cozy IV powered by Turbo = Subaru 3.0R=20 with variable valve lift and cam timing.
Artificial intelligence = in=20 cockpit, N9032U 240+ hours from Portland, Oregon
Glass panel = design, Subaru=20 install, Prop construct, Risk assessment info:
htt= p://www.maddyhome.com/canardpages/pages/alwick/index.html
 
 
 
----- Original Message -----
From:=20 Ed Anderson
To: Rotary motors in = aircraft=20
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=20 have supported flight in that condition (air in coolant) , then you = are=20 quite correct, on the other hand, one of the reasons to test (as you = have=20 often pointed out) is to discover problems before flight inorder to = preclude=20 failures in the air.  In this case, I discovered my = configuration=20 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=20 to the proper operating parameters. 
 
Even in the automobile, the rotary is known = for=20 trapping air and requiring burping although many can get away = without it=20 because most autos don't operate anywhere near WOT for more than a = few=20 seconds, so the effects of trapped air (depending on = amount) may=20  not be noticed. 
 
   I think there is a difference, = for=20 instance you could design the perfect coolant system but fail to put = sufficient coolant into the system resulting in overheating - is = that a=20 system failure or a operational failure? or perhaps more = accurately -=20 operator failure? 
 
I am always  impressed by your = meticulous=20 attention to detail and systematic approach.  I  could = certainly=20 have benefit from your knowledge/approach  back 10 years ago in = my=20 initial design{:>).  But at that time, there appear to be = bigger=20 issues - such as trying to understand how  a = rotary engine=20 really worked - sorted out.  Air flow and cooling = were just=20 vague notions back then and I just assume they would naturally fall = into=20 place {:>)
 
 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=20 2 1/2" dia hose piping air to one corner.  Is there small = wonder that=20 my 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=20 the brown colored box on the left side of the engine (facing the = engine)=20 close to the firewall with the large back hose (that one is 5" in = dia as one=20 of my several  early attempts to address the oil temp = problems). =20 The 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=20 may sometimes take issue with your characterization, but not your = approach=20 and 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=20 Water Pressure

>at 22 psi the air would likely occupy = even more=20 space
 
The opposite is true. Air space reduces=20 substantially when you increase pressure. Think of coolant as = a=20 solid, and air as a giant spring. When you add btu's to coolant, = it=20 immediately responds by expanding. This causes the air molecules = to=20 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 = compress(less air volume). This allows water to displace that=20 air....dropper is now heavier and falls to bottom.
 
It's really ironic. You can design a = system that=20 seems to work fine. You fly with that for years with no failures( = well I=20 guess you could call the pinging and high temps a failure). But a = small=20 change can greatly reduce your risk. There's a lot of value to = changing=20 your air bleed design to one that dynamically removes air. No = shrader=20 valve, no repeated cooling cycles to remove air. By "dynamic" I = mean that=20 it automatically removes air from the system. No muss no fuss.=20
 
As you design system, just pretend their = is air at=20 the top of each component. Then find simple way to allow that air = to move=20 to higher component in system. So, my radiator is lowest point in = system.=20 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=20 passage in engine. In my case I had to drill and tap a little 1/4 = npt into=20 the coolant manifold, then run tube from there up to highest point = in=20 system. Suddenly I've got a system that automatically removes all = air=20 immediately. Try as I can, I can no longer trap air anywhere. If I = develop=20 compression leak that pumps air into system, it has much less = effect,=20 because it rises out of the coolant flow. When I drain and refill, = it all=20 immediately and rapidly fills, I can get every drop back into the=20 system.
 
Dynamic air bleed is a safety = advantage, easy=20 to accomplish. Each of these safety advantages adds up = mathematically.=20
Likewise, contrary to popular theory, = leaving two=20 cups of air under cap increases safety. You can prove that to = yourself=20 with 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=20 more space, but since I do my runup with the cap off or loose, = there is=20 no pressure during the process.  So while I have never = measured it=20 and it probably varies from one time to the next, there appears = to be=20 approx 1/3 of the top part of each core which has air on the = initial=20 fire up of 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,=20 I almost cooked the engine, because I assumed that when the = header tank=20 was full - the engine had all the coolant it could take.  = Rapidly=20 climbing coolant temps and pinging of hot engine cooling off = soon make=20 it 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=20 amount of air left, but the overflow tank set gradually removes = the=20 remaining air over a couple of flights.  Then the hydraulic = "lock"=20 phenomena starts with initial pressure of 21-22 psi immediately = on=20 engine start, dropping off  quickly to zero and then = gradually=20 climbing  back to 5 - 7 psi as the coolant heats =20 up.
 
 
But, other than having to "clear" the = air out with=20 a couple/three run ups to 5000 rpm, it works just fine and has = since=20 97.  I occasionally toy with the idea of putting in simple = small=20 air 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=20 aircraft
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=20 I 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=20 doesn't fit the outlet may exit the bottom of the tank but = will have=20 an internal standpipe - this way there is next to no space = where air=20 can get trapped, just a small bubble atop the standpipe, won't = be big=20 enough to cause any cooling detriment.
I still see BMW motorcycle oil-coolers mounted this way. = Don't=20 know the exact make-up today, but the earliest ones where = simple=20 single pass bottom feed bottom exit (cheapest solution and=20 esthetically least disturbing), a big problem to purge. 1/4 = was=20 useless because of trapped 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=20 had a fresh load of cold air inthe cooler! As it heats up the=20 air-bubble expands and reduces cooler volume even more... =
 
Best Regards,
 
TJ

snipped..
 In my case, if I do a = complete=20 drain and refill of the system, on the first run up the = core's tanks=20  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=20 the way from top to bottom.  So depending on your = radiator set=20 up 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_000A_01C80775.A353DF10--