X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost05.isp.att.net ([207.115.11.55] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2366249 for flyrotary@lancaironline.net; Wed, 03 Oct 2007 11:12:39 -0400 Received-SPF: pass receiver=logan.com; client-ip=207.115.11.55; envelope-from=bbradburry@bellsouth.net Received: from arptk8ng400 (adsl-146-124-76.mco.bellsouth.net[72.146.124.76]) by bellsouth.net (frfwmhc05) with SMTP id <20071003151158H0500702i9e>; Wed, 3 Oct 2007 15:11:58 +0000 X-Originating-IP: [72.146.124.76] From: "Bill Bradburry" To: "'Rotary motors in aircraft'" In-Reply-To: Subject: RE: [FlyRotary] Re: Coolant Water Pressure Date: Wed, 3 Oct 2007 11:12:01 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000C_01C805AE.398B0680" X-Mailer: Microsoft Office Outlook, Build 11.0.5510 Thread-Index: AcgFycFRv+a9/+H+T6ScHDma8jisagABEDeg X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16480 Message-ID: This is a multi-part message in MIME format. ------=_NextPart_000_000C_01C805AE.398B0680 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Lynn, My system does not have an accumulator in it presently. My system is just like the older cars. The radiator cap on the radiator has an overflow tube that allows burped coolant to go into the bottom of a catch can. When the pressure lowers the coolant can be sucked back into the radiator through the cap. The catch can is not pressurized. This is like both my cars. Yesterday, I visited the local Mazda dealership and had a mechanic show me the system on the RX8. That system has a hose that comes from the inlet of the water pump and goes into a pressurized plastic container. This container has a pressure cap on top that can burp water out into a hose that appears to go on to the ground. (I didn't see a catch can?) I will try and rig up an accumulator as you describe. Why do you pressurize the system before you start the engine? Seems that after start, the pressure would build higher, causing it to burp out. Are you trying to cause a minimum constant 22 lbs by pre-pressuring? 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. 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. 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. 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. 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. Trapped air pops to the top of the bottle and that is plumbed to the bottom of the accumulator as above. You used to get the plans for this thing when you buy a Cosworth race engine. Does Cosworth know something you don't? 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. 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. 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. 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. Lynn E. Hanover _____ See what's new at AOL.com and Make AOL Your Homepage. ------=_NextPart_000_000C_01C805AE.398B0680 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Lynn, My system does not have an accumulator in it = presently.

My system is just like the older cars.  The radiator cap on the radiator has an overflow tube that = allows burped coolant to go into the bottom of a catch can.  When the = pressure lowers the coolant can be sucked back into the radiator through the = cap.  The catch can is not pressurized.  This is like both my = cars.

 

Yesterday, I visited the local = Mazda dealership and had a mechanic show me the system on the RX8.  That = system has a hose that comes from the inlet of the water pump and goes into a pressurized plastic container.  This container has a pressure cap = on top that can burp water out into a hose that appears to go on to the ground. = (I didn’t see a catch can?)

 

I will try and rig up an = accumulator as you describe.

 

Why do you pressurize the system = before you start the engine?  Seems that after start, the pressure would = build higher, causing it to burp out.  Are you trying to cause a minimum = constant 22 lbs by pre-pressuring?

 

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. =

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. 

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. 

 

=

 

=

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. =

 

=

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.

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

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

 

=

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. =

 

=

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.

 

=

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. =

 

=

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. 

 

=

Lynn E. = Hanover 



See what's new at AOL.com and Mak= e AOL Your Homepage.

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