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 2383909 for flyrotary@lancaironline.net; Fri, 12 Oct 2007 16:31:11 -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 smtpout05.dca.untd.com with SMTP id AABDS9YLKANELVM2 for (sender ); Fri, 12 Oct 2007 13:30:01 -0700 (PDT) Message-ID: <9E1655F172734319BB7607FE2A2E37F4@Penny> From: "Al Wick" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] FW: [FlyRotary] Re: Coolant Water Pressure Date: Fri, 12 Oct 2007 13:29:20 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0128_01C80CD3.E53C0D90" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6000.16480 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16545 X-ContentStamp: 76:38:1449875289 X-MAIL-INFO:0d13beaabef7dadbf7ababdfabdadbfa67cf37ef9a8f5a83ca4b37cfd3f36a176a8ba38e8b1e1e9e1ea38e6eef4aca8a27139adeced3ca4ab38acaf39373deeab76f63cbc7ce4ba78fbafb1f9bfb4b3b5a3b6b7b0a479b27d703477b2f6e2f1f07d7022f3baa5edb5e979a1a97db4adedbfab76303834e3b5acb3fa7333be3372abebe9f07af771eaa7ede8eabaafa4a4a57ab3af3b78a939793c79e6f6fbf67038f2b021fa7bf43a74b737ad7e7a727ea5f0b6727e7d7273f277b7f77ce576febbffebfb367474bd33e472b03ba776e8e2fbf3b774b87bb7ebb3b9f27ba7eab4fbe37abfabf2f3f9faacadeda63be635b033a5e4a97abfa93c3 c373cb6aca6f6bb79e X-UNTD-OriginStamp: L941HVjjYzDhN3itp//mkHwK74QfPNnm+EVmt/BV2MP94PsrVOXCdg== X-UNTD-Peer-Info: 10.171.42.35|smtpout05.dca.untd.com|smtpout05.dca.untd.com|alwick@juno.com This is a multi-part message in MIME format. ------=_NextPart_000_0128_01C80CD3.E53C0D90 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Where does the fear of pump cavitation come from? Is that speculative or = have some guys inadvertently choked off the pump inlet with small diam = hose instead of OEM size? -al wick ----- Original Message -----=20 From: Al Gietzen=20 To: Rotary motors in aircraft=20 Sent: Friday, October 12, 2007 11:31 AM Subject: [FlyRotary] FW: [FlyRotary] Re: Coolant Water Pressure This was rejected because of the photo files being too large, so I'll = send one of the pics separately. Al Subject: RE: [FlyRotary] Re: Coolant Water Pressure Bill; Here is the setup I use. On the first photo, the filler neck is on the = left, and connects to the line going to the inlet side of the pump. The = two small lines (3/16") coming into the side are air bleed lines going = from the high points of my two radiators (note that the pressure at the = filler neck will be near the lowest in the system.) The 'overflow' from = the filler cap goes to the bottom of the accumulator bottle on the right = (made from a discarded fire extinguisher). The accumulator bottle overflow goes over board, but coolant only goes = out here once on first heatup. When cold, there is only about 3 - 4" = coolant in the bottom of that bottle, so there is air in there that = compresses as things heat up. Coolant forced out of the filler neck on = heat up is draw back in on cooldown. The idea is that whenever the engine is running, there is positive = pressure on the system - at the pump inlet; reducing the chance of pump = cavitation at high RPM. And positive pressure is maintained at altitude = even when throttling back and the coolant temp is decreasing. Originally I had a 23# cap on the filler neck, and 15# on the = accumulator bottle. I later reversed the two to lower system pressure = on initial heatup (as soon as the engine heats up at all the pressure = goes to filler cap pressure), but it still gives me the sum of the two = caps under any extreme condition to protect against boiling. Keep in = mind that the caps are 'differential pressure' so at altitude the max = absolute pressure in the accumulator bottle is reduced by the reduction = in the ambient. Al -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Bill Bradburry Sent: Thursday, October 11, 2007 8:49 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Coolant Water Pressure Lynn, I don't know what we would do without you. I have several questions. =20 Where can I get a good accumulator tank? =20 I was thinking of making one out of a used fire extinguisher and was = also looking at one from Moroso that looks like a flat canteen. The one = from Moroso has an inlet on the bottom and one on the top side as well = as one for the pop off of the radiator cap. Due to space constraints, I = will probably try and make one. I need something about 3" diameter and = maybe 12" or so long. Will I need the inlet on the top side? If so, = where does it plumb to? I suppose I will still need an overflow tank from the pop off of the = radiator cap? After talking with Tracy yesterday, I tried to see if the engine = would stabilize temp somewhere below 230* at 2600 rpm. No joy! I = suspect that I will need to increase air flow to get this to happen. I = will try an leaf blower on the cowl today. My pressure stabilized at 22 lbs (cap in constant blow off relief) but = the temp would not hold. If I had this same condition with the system = you described, what would prevent the air from blowing off and then = water from the accumulator? It seems to me that no matter what system you have, the pressure has = to stabilize below the pressure rating of the radiator cap, else you = will be losing first air, then water???? Bill B -------------------------------------------------------------------------= ----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Lehanover@aol.com Sent: Wednesday, October 03, 2007 10:28 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Coolant Water Pressure In a message dated 10/3/2007 9:08:53 A.M. Eastern Daylight Time, = bbradburry@bellsouth.net writes: I think that I would see air under the radiator cap if I had a = compression gas leak? I never see any air.=20 To check a piston engine for head gasket leaks, you would put the = cylinder at TDC and pressurize the cylinder to about 150 lbs with = compressed air and check the radiator for air bubbles.How do you check a = rotary? I will check the pressure sender against a mechanical gage. =20 There is obviously a heating problem, but I think the pressure is = higher than it should be until just ready to boil. I shut the engine = off at 210*, and at 22+ lbs, the boiling point should be well above = 250*?? Thanks for the suggestions of where to look, guys. Bill B It is extremely difficult to remove all of the air from a rotary = engines cooling system. It is also extremely important. If air is under = the pressure cap in a static situation, it will remix with other coolant = when the engine is at speed. The coolant moves very quickly through the = system. The coolant volume appears to increase slightly because much of = the air is reintroduced into the water. This coolant then becomes a poor = conductor of heat. You need the anti foaming agent in Antifreeze. Just a = bit, perhaps 10%. The system with the relief cap right on the radiator = or filler point, starts to offload coolant as soon as the engine is = started. It is in hydraulic lock, and has a small volume. The actual = boiling point calculated for this coolant makes no difference at all. = The cap opens a bit when the trip pressure is attained, the pressure = drops to 22 PSI or whatever for your cap, and a bit more heating trips = the cap again. It is exactly the same as most cars. So, at first in each heat cycle, there may be no correlation between = coolant temperature, and the actual amount of coolant dumped by the cap. = This is only true closer to a constant operating temperature. And then = pressure may be alarmingly unstable with power changes. The accumulator = system makes pressure rock solid.=20 Make the pressure cap into a filler cap, sealing only the top lip of = the radiator or filling port. Connect only a bleed hose and run it to = the bottom of a recovery bottle, and put the pressure relief cap on that = bottle. Keep the bottle about 1/3 full. Note after several heat cycles, = the amount of water you need to add to keep that bottle 1/3 full is = reduced each time. Once all of the air is out of the cooling system, no = more coolant need be added to the bottle.=20 Heating and cooling of the system, makes sweeping changes in coolant = volume. The air cushion in the bottle acts as an accumulator (used in = thousands of aircraft) to maintain a constant pressure and coolant = supply. Race cars use a Rolairtrol or spin bottle in the hose from the top of = the engine to the radiator. Water enters the bottle at about half height = on a tangent and adds a spinning motion. Water leaves through a center = hole at the bottom.=20 Trapped air pops to the top of the bottle and that is plumbed to the = bottom of the accumulator as above.=20 You used to get the plans for this thing when you buy a Cosworth race = engine. Does Cosworth know something you don't?=20 Anyway, after about three heat cycles (operating temperature and back = to room temperature) the coolant system will be solid coolant with all = of the air removed. It will not be hydraulically locked against the cap. It will have the relief cap pressure, and will hold that for as long = as the engine is hot.=20 I have a Shrader valve installed in my accumulator tank, and before I = start the engine I charge that bottle with compressed air until the cap = relieves at 22 PSI. Now I know it has pressure, and I know it has 22 = PSI. This was the stock system on all Mazda cars in the 70s. I didn't = invent it.=20 It is unlikely that you have leaking compression seals, unless there = is coolant blowing out of your makeup tank, or coolant is running out of = your exhaust system after shutdown.=20 My recovery bottle is mounted where the passenger foot well would have = been. Even with the bottom of the engine. So long as the hose ID is less = than 1/4" and the hose enters the bottle on the bottom of the coolant = supply, it matters not at all where that bottle is located. There is a = money back guarantee with this system.=20 Lynn E. Hanover=20 -------------------------------------------------------------------------= ----- See what's new at AOL.com and Make AOL Your Homepage. -------------------------------------------------------------------------= ----- -- 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_0128_01C80CD3.E53C0D90 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Where does the fear of pump cavitation = come from?=20 Is that speculative or have some guys inadvertently choked off the pump = inlet=20 with small diam hose instead of OEM size?
 
 
 
-al wick
----- Original Message -----
From:=20 Al = Gietzen=20
Sent: Friday, October 12, 2007 = 11:31=20 AM
Subject: [FlyRotary] FW: = [FlyRotary] Re:=20 Coolant Water Pressure

This was rejected = because of the=20 photo files being too large, so I=92ll send one of the pics=20 separately.

Al

Subject: RE:=20 [FlyRotary] Re: Coolant Water Pressure

 

Bill;

 

Here is = the setup I=20 use. On the first photo, the filler neck is on the left, and connects = to the=20 line going to the inlet side of the pump.  The two small lines = (3/16=94)=20 coming into the side are air bleed lines going from the high points of = my two=20 radiators (note that the pressure at the filler neck will be near the = lowest=20 in the system.)  The =91overflow=92 from the filler cap goes to = the bottom of=20 the accumulator bottle on the right (made from a discarded fire=20 extinguisher).

 

The = accumulator=20 bottle overflow goes over board, but coolant only goes out here once = on first=20 heatup.  When cold, there is only about 3 =96 4=94 coolant in the = bottom of=20 that bottle, so there is air in there that compresses as things heat = up. =20 Coolant forced out of the filler neck on heat up is draw back in on=20 cooldown.

 

The idea = is that=20 whenever the engine is running, there is positive pressure on the = system =96 at=20 the pump inlet; reducing the chance of pump cavitation at high RPM. =  And=20 positive pressure is maintained at altitude even when throttling back = and the=20 coolant temp is decreasing.

 

Originally I had a=20 23# cap on the filler neck, and 15# on the accumulator bottle.  I = later=20 reversed the two to lower system pressure on initial heatup (as soon = as the=20 engine heats up at all the pressure goes to filler cap pressure), but = it still=20 gives me the sum of the two caps under any extreme condition to = protect=20 against boiling.  Keep in mind that the caps are =91differential = pressure=92=20 so at altitude the max absolute pressure in the accumulator bottle is = reduced=20 by the reduction in the ambient.

 

Al

 

-----Original=20 Message-----
From: = Rotary=20 motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bill = Bradburry
Sent: Thursday, October=20 11, 2007 8:49=20 AM
To: Rotary motors in = aircraft
Subject: [FlyRotary] Re: = Coolant Water=20 Pressure

 

Lynn, I don=92t = know what=20 we would do without you.

I have=20 several questions. 

Where=20 can I get a good accumulator tank? 

I was=20 thinking of making one out of a used fire extinguisher  and was = also=20 looking at one from Moroso that looks like a flat canteen.  The = one from=20 Moroso has an inlet on the bottom and one on the top side as well as = one for=20 the pop off of the radiator cap.  Due to space constraints, I = will=20 probably try and make one. I need something about 3=94 diameter and = maybe 12=94 or=20 so long.   Will I need the inlet on the top side?  If = so, where=20 does it plumb to?

I=20 suppose I will still need an overflow tank from the pop off of the = radiator=20 cap?

After=20 talking  with Tracy yesterday, = I tried=20 to see if the engine would stabilize temp somewhere below 230* at 2600 = rpm.  No joy!  I suspect that I will need to increase air = flow to=20 get this to happen.  I will try an leaf blower on the cowl=20 today.

My=20 pressure stabilized at 22 lbs (cap in constant blow off relief) but = the temp=20 would not hold.  If I had this same condition with the system you = described, what would prevent the air from blowing off and then water = from the=20 accumulator?

It seems=20 to me that no matter what system you have, the pressure has to = stabilize below=20 the pressure rating of the radiator cap, else you will be losing first = air,=20 then water????

 

Bill=20 B

 

From: Rotary=20 motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of=20 Lehanover@aol.com
Sent: Wednesday, October=20 03, 2007 10:28=20 AM
To: Rotary motors in = aircraft
Subject: [FlyRotary] Re: = Coolant Water=20 Pressure

 

In a=20 message dated 10/3/2007 = 9:08:53=20 A.M. Eastern = Daylight=20 Time, bbradburry@bellsouth.net writes:

I=20 think that I would see air under the radiator cap if I had a = compression gas=20 leak?  I never see any air.

To=20 check a piston engine for head gasket leaks, you would put the = cylinder at=20 TDC and pressurize the cylinder to about 150 lbs with compressed air = and=20 check the radiator for air bubbles=85How do you check a=20 rotary?

I will=20 check the pressure sender against a mechanical gage. =20

There=20 is obviously a heating problem, but I think the pressure is higher = than it=20 should be until just ready to boil.  I shut the engine off at = 210*, and=20 at 22+ lbs, the boiling point should be well above = 250*??

 

Thanks=20 for the suggestions of where to look, guys=85

 

Bill=20 B

It is=20 extremely difficult to remove all of the air from a rotary engines = cooling=20 system. It is also extremely important. If air is under the pressure = cap in a=20 static situation, it will remix with other coolant when the engine is = at=20 speed. The coolant moves very quickly through the system. The coolant = volume=20 appears to increase slightly because much of the air is reintroduced = into the=20 water. This coolant then becomes a poor conductor of heat. You need = the anti=20 foaming agent in Antifreeze. Just a bit, perhaps 10%. The system with = the=20 relief cap right on the radiator or filler point, starts to offload = coolant as=20 soon as the engine is started. It is in hydraulic lock, and has a = small=20 volume. The actual boiling point calculated for this coolant makes no=20 difference at all. The cap opens a bit when the trip pressure is = attained, the=20 pressure drops to 22 PSI or whatever for your cap, and a bit more = heating=20 trips the cap again. It is exactly the same as most=20 cars.

So, at=20 first in each heat cycle, there may be no correlation between coolant=20 temperature, and the actual amount of coolant dumped by the cap. This = is only=20 true closer to a constant operating temperature. And then pressure may = be=20 alarmingly unstable with power changes. The accumulator system makes = pressure=20 rock solid. 

 

 

Make=20 the pressure cap into a filler cap, sealing only the top lip of the = radiator=20 or filling port. Connect only a  bleed hose and run it to = the bottom=20 of a recovery bottle, and put the pressure relief cap on that bottle. = Keep the=20 bottle about 1/3 full. Note after several heat cycles, the amount of = water you=20 need to add to keep that bottle 1/3 full is reduced each time. Once = all of the=20 air is out of the cooling system, no more coolant need be added to the = bottle.=20

 

Heating=20 and cooling of the system, makes sweeping changes in coolant volume. = The air=20 cushion in the bottle acts as an accumulator (used in thousands of = aircraft)=20 to maintain a constant pressure and coolant = supply.

 

Race=20 cars use a Rolairtrol or spin bottle in the hose from the top of the = engine to=20 the radiator. Water enters the bottle at about half height on a = tangent and=20 adds a spinning motion. Water leaves through a center hole at the = bottom.=20

Trapped=20 air pops to the top of the bottle and that is plumbed to the bottom of = the=20 accumulator as above.

You=20 used to get the plans for this thing when you buy a Cosworth race = engine. Does=20 Cosworth know something you don't? 

 

Anyway,=20 after about three heat cycles (operating temperature and back to room=20 temperature) the coolant system will be solid coolant with all of the = air=20 removed. It will not be hydraulically locked against the=20 cap.

It will=20 have the relief cap pressure, and will hold that for as long as the = engine is=20 hot.

 

I have=20 a Shrader valve installed in my accumulator tank, and before I start = the=20 engine I charge that bottle with compressed air until the cap relieves = at 22=20 PSI. Now I know it has pressure, and I know it has 22=20 PSI.

 

This=20 was the stock system on all Mazda cars in the 70s. I didn't invent it. =

 

It is=20 unlikely that you have leaking compression seals, unless there is = coolant=20 blowing out of your makeup tank, or coolant is running out of your = exhaust=20 system after shutdown.

 

My=20 recovery bottle is mounted where the passenger foot well would have = been. Even=20 with the bottom of the engine. So long as the hose ID is less than = 1/4" and=20 the hose enters the bottle on the bottom of the coolant supply, it = matters not=20 at all where that bottle is located. There is a money back guarantee = with this=20 system. 

 

Lynn E.=20 Hanover 

 

See=20 what's new at AOL.com=20 and Make AOL Your = Homepage.

--
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
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