X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imo-d22.mx.aol.com ([205.188.144.208] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2382635 for flyrotary@lancaironline.net; Fri, 12 Oct 2007 00:58:30 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.144.208; envelope-from=Lehanover@aol.com Received: from Lehanover@aol.com by imo-d22.mx.aol.com (mail_out_v38_r9.3.) id q.d30.1895278d (30739) for ; Fri, 12 Oct 2007 00:57:47 -0400 (EDT) From: Lehanover@aol.com Message-ID: Date: Fri, 12 Oct 2007 00:57:47 EDT Subject: Re: [FlyRotary] Re: Coolant Water Pressure To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1192165067" X-Mailer: 9.0 Security Edition for Windows sub 5378 X-Spam-Flag: NO -------------------------------1192165067 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en In a message dated 10/11/2007 12:49:41 P.M. Eastern Daylight Time, =20 bbradburry@bellsouth.net writes: Lynn, I don=E2=80=99t know what we would do without you.=20 I have several questions. =20 Where can I get a good accumulator tank? =20 =20 Circle track racing catalogs, hot rod shops. I was 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 fo= r the=20 pop off of the radiator cap. Due to space constraints, I will probably try= =20 and make one. I need something about 3=E2=80=9D diameter and maybe 12=E2= =80=9D or so long. =20 Will I need the inlet on the top side? =20 I have no idea what the top one would be used for, maybe a pressure gage? If so, where does it plumb to? I suppose I will still need an overflow tank from the pop off of the=20 radiator cap? =20 In racing it is required that a 32 Oz. catch tank be supplied to accept tha= t=20 hose. Just to keep coolant off of the track. Being able to catch that=20 coolant, is of no value, as it will not return to the system until the engi= ne is=20 close to cold. If a seal blows out and coolant uses up the remaining volume= of=20 the make-up tank, it will then overboard into the catch tank, or, you could= =20 route that hose up in front of the windscreen, and you will be the first to= =20 know that you need to be on the ground looking at this coolant problem. In a= =20 conventional system, no coolant can return to the system until the system dr= ops =20 below ambient pressure. That will be when the engine is just about cold. Wit= h=20 the coolant slugged tight against the cap, coolant leaves as pressure build= s=20 above the relief pressure. So it pees out coolant until top temperature is=20= =20 reached.=20 So the coolant is at top temp, and at relief pressure, say 24 pounds. When=20 you power back a bit, and the coolant temp drops, the coolant shrinks, and=20= the=20 pressure drops. But nothing can get back into the system from the make-up=20 tank. So after a long climb you level off and cool things down a bit, and n= ow=20 you have little or no pressure. =20 The air cushion in the Mazda system keeps pushing coolant back into the=20 system with temperature changes. The air cushion stays at the relief pressu= re, or=20 close to it, the whole time the engine runs. Every time the system finds a=20 little bubble of air it pops up into the make up tank, and is replaced by=20 coolant.. =20 =20 After talking with Tracy yesterday, I tried to see if the engine would=20 stabilize temp somewhere below 230* at 2600 rpm. No joy! I suspect that I= will=20 need to increase air flow to get this to happen. I will try an leaf blower= =20 on the cowl today.=20 My pressure stabilized at 22 lbs (cap in constant blow off relief) but the=20 temp would not hold. If I had this same condition with the system you=20 described, what would prevent the air from blowing off and then water from=20= the =20 accumulator? As the engine heats the coolant, it expands a bit. The pressure in the air=20 bottle goes up compressing the air. Should the air reach the relief pressure, the cap will vent to the cap=20 value, 22 pounds. (now I remember why I have a Shrader valve in the bottle).= Once=20 all of the air is removed from the coolant, it may not expand enough at 180=20= =20 degrees, to generated the cap pressure, so I add air until the cap cycles. T= hen=20 start the engine. A few days after a race, and there is still pressure in=20 the system. =20 It seems to me that no matter what system you have, the pressure has to=20 stabilize below the pressure rating of the radiator cap, else you will be l= osing=20 first air, then water???? The coolant won't expand very much from just heating it. If the bottle=20 volume is too large it won't even trip the cap. Some car systems now just h= ave a=20 fill cap with no relief function at all just the air volume to compensate f= or=20 volume changes. Bill B=20 Lynn E. Hanover=20 ************************************** See what's new at http://www.aol.com -------------------------------1192165067 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en
In a message dated 10/11/2007 12:49:41 P.M. Eastern Daylight Time,=20 bbradburry@bellsouth.net writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000080 size= =3D2>

Lynn, I don=E2=80= =99t know what=20 we would do without you.

I have several=20 questions. 

Where can I get= a=20 good accumulator tank? 

 

= Circle track=20 racing catalogs, hot rod shops.

I was thinking=20= of=20 making one out of a used fire extinguisher  and was also looking at o= ne=20 from Moroso that looks like a flat canteen.  The one from Moroso has=20= an=20 inlet on the bottom and one on the top side as well as one for the pop off= of=20 the radiator cap.  Due to space constraints, I will probably try and=20= make=20 one. I need something about 3=E2=80=9D diameter and maybe 12=E2=80=9D or s= o long. =20  Will I need the inlet on the top=20 side? 

I have no idea what the top one would be used for, maybe a pres= sure=20 gage?

If so, w= here does it=20 plumb to?

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

In racing it is required that a 32 Oz. catch tank be supplied t= o=20 accept that hose. Just to keep coolant off of the track. Being able to catch= =20 that coolant, is of no value, as it will not return to the system until the=20 engine is close to cold. If a seal blows out and coolant uses up the remaini= ng=20 volume of the make-up tank, it will then overboard into the catch tank, or,=20= you=20 could route that hose up in front of the windscreen, and you will be the fir= st=20 to know that you need to be on the ground looking at this coolant problem. I= n a=20 conventional system, no coolant can return to the system until the system dr= ops=20 below ambient pressure. That will be when the engine is just about cold. Wit= h=20 the coolant slugged tight against the cap, coolant leaves as pressure builds= =20 above the relief pressure. So it pees out coolant until top temperature is=20 reached.
So the coolant is at top temp, and at relief pressure, say 24=20 pounds. When you power back a bit, and the coolant temp drops, the coolant=20 shrinks, and the pressure drops. But nothing can get back into the system fr= om=20 the make-up tank. So after a long climb you level off and cool things down a= =20 bit, and now you have little or no pressure.
 
The air cushion in the Mazda system keeps pushing coolant back=20= into=20 the system with temperature changes. The air cushion stays at the relief=20 pressure, or close to it, the whole time the engine runs. Every time th= e=20 system finds a little bubble of air it pops up into the make up tank, and is= =20 replaced by coolant..    
 

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

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

As the engine heats the coolant, it expands a bit. The pressure= in=20 the air bottle goes up compressing the air.
Should the air reach the relief pressure, the cap will vent to=20= the=20 cap value, 22 pounds. (now I remember why I have a Shrader valve in the bott= le).=20 Once all of the air is removed from the coolant, it may not expand enough at= 180=20 degrees, to generated the cap pressure, so I add air until the cap cycles. T= hen=20 start the engine. A few days after a race, and there is still pressure in th= e=20 system.
 

 

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

The coolant won't expand very much from just heating it. If the= =20 bottle volume is too large it won't even trip the cap. Some car systems now=20= just=20 have a fill cap with no relief function at all just the air volume to compen= sate=20 for volume changes.

Bill=20 B

 

Lynn E.=20 Hanover

 



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