X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost05.isp.att.net ([204.127.217.105] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2381618 for flyrotary@lancaironline.net; Thu, 11 Oct 2007 12:49:08 -0400 Received-SPF: pass receiver=logan.com; client-ip=204.127.217.105; envelope-from=bbradburry@bellsouth.net Received: from arptk8ng400 (adsl-146-123-217.mco.bellsouth.net[72.146.123.217]) by bellsouth.net (frfwmhc05) with SMTP id <20071011164828H05006n6v1e>; Thu, 11 Oct 2007 16:48:28 +0000 X-Originating-IP: [72.146.123.217] From: "Bill Bradburry" To: "'Rotary motors in aircraft'" In-Reply-To: Subject: RE: [FlyRotary] Re: Coolant Water Pressure Date: Thu, 11 Oct 2007 12:48:44 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0000_01C80C05.0F1DCC40" X-Mailer: Microsoft Office Outlook, Build 11.0.5510 Thread-Index: AcgFycFRv+a9/+H+T6ScHDma8jisagGWjD4g X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16545 Message-ID: This is a multi-part message in MIME format. ------=_NextPart_000_0000_01C80C05.0F1DCC40 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Lynn, I don't know what we would do without you. I have several questions. Where can I get a good accumulator tank? 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. 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_0000_01C80C05.0F1DCC40 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Lynn, I don’t know what we would do without you.

I have several questions.  =

Where can I get a good accumulator = tank? 

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. =

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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