Return-Path: <13brv3@bellsouth.net> Received: from imf22aec.mail.bellsouth.net ([205.152.59.70] verified) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 2783223 for flyrotary@lancaironline.net; Thu, 04 Dec 2003 09:28:21 -0500 Received: from rad ([68.212.0.112]) by imf22aec.mail.bellsouth.net (InterMail vM.5.01.06.05 201-253-122-130-105-20030824) with ESMTP id <20031204142820.STEI1942.imf22aec.mail.bellsouth.net@rad> for ; Thu, 4 Dec 2003 09:28:20 -0500 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Expansion Chambers Date: Thu, 4 Dec 2003 08:28:23 -0600 Message-ID: <003c01c3ba72$df7e72b0$6001a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_003D_01C3BA40.94E402B0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 This is a multi-part message in MIME format. ------=_NextPart_000_003D_01C3BA40.94E402B0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable I've come to the point where I need to set up the expansion / overflow system. My engine guy is saying I can just have an overflow reservoir = since the pressure cap is at the top of the engine. I've read that some 13B = flyers (if not all) have expansion chambers which, in turn, have their own = overflow reservoirs. =20 Hi John, =20 The later RX-7's (not sure when they started it) used an Air Separator = Tank (AST), and an overflow jug. The AST only has to be a small tank, maybe = a pint, and must have a pressure cap on it. Mazda actually used a plastic tank on the FD, though most folks end up replacing it with an aluminum = one. The cars also have a fill port at the high point in the system, which is = a plain cap (no relief valve). =20 =20 I copied this system, with the exception of not having room for a fill = cap, which means I have to remove the top hose to fill the engine. That will = be corrected in rev-2 btw. If you have room for a large 1.5 qt or so pressurized tank, such that the top half or so of the tank is above the = high point of the engine, I would bet that it would make a dandy AST, and overflow tank. =20 =20 On the other hand, lots of FD guys just remove the AST, and move the pressure cap to the fill port, effectively doing just what your engine = guy suggested. This is always a hot debate, and it probably isn't ideal, = but it seems to work just fine as long as you burp the system properly to get = the air out. I may do this myself on rev-2, just to eliminate some clutter. = =20 =20 Cheers, Rusty (actively job hunting) =20 ------=_NextPart_000_003D_01C3BA40.94E402B0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message

I've come to the point where I need to set up the = expansion /=20 overflow system. My engine guy is saying I can just have an overflow = reservoir=20 since the pressure cap is at the top of the engine. I've read that some = 13B=20 flyers (if not all) have expansion chambers which, in turn, have their = own=20 overflow reservoirs.

 
Hi=20 John,
 
The = later RX-7's (not=20 sure when they started it) used an Air Separator Tank (AST), and an = overflow=20 jug.  The AST only has to be a small tank, maybe a pint, and must = have a=20 pressure cap on it.  Mazda actually used a plastic tank on the FD, = though=20 most folks end up replacing it with an aluminum one.  The cars also = have a=20 fill port at the high point in the system, which is a plain cap (no = relief=20 valve).  
 
I copied = this system,=20 with the exception of not having room for a fill cap, which means I = have to=20 remove the top hose to fill the engine.  That will be corrected in = rev-2=20 btw.  If you have room for a large 1.5 qt or so pressurized = tank, such=20 that the top half or so of the tank is above = the high point=20 of the engine,  I would bet that it would make = a dandy AST,=20 and overflow tank.  
 
On the = other hand, lots=20 of FD guys just remove the AST, and move the pressure cap to the fill = port,=20 effectively doing just what your engine guy suggested.  This = is always=20 a hot debate, and it probably isn't ideal, but it seems to work = just fine=20 as long as you burp the system properly to get the air out.  I = may do=20 this myself on rev-2, just to eliminate some=20 clutter.  
 
Cheers,
Rusty = (actively job=20 hunting) 
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