X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ispmxmta09-srv.alltel.net ([166.102.165.170] verified) by logan.com (CommuniGate Pro SMTP 5.0.4) with ESMTP id 888277 for flyrotary@lancaironline.net; Mon, 19 Dec 2005 11:57:41 -0500 Received-SPF: pass receiver=logan.com; client-ip=166.102.165.170; envelope-from=montyr2157@alltel.net Received: from Thorstwin ([4.89.244.215]) by ispmxmta09-srv.alltel.net with SMTP id <20051219165654.REFC12342.ispmxmta09-srv.alltel.net@Thorstwin> for ; Mon, 19 Dec 2005 10:56:54 -0600 Message-ID: <002601c604bd$3f95cdb0$d7f45904@Thorstwin> From: "Monty Roberts" To: Subject: Heat Exchangers Date: Mon, 19 Dec 2005 10:57:07 -0600 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0023_01C6048A.F45B9B40" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_0023_01C6048A.F45B9B40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sounds like plenty of core area to me Monty. =20 Thought I had made my final decision on the oil cooler but still having = trouble getting all my design goals to work with the fluidyne cooler. = Those darn evap cores are hard to beat for weight, performance & size. = I'm back to figuring out a way to make the evap core reliable in oil = cooler service. =20 Rusty is the resident expert on failures on these things so a couple of = questions for him. =20 Were the connections on the end tanks welded on? I'm wondering if the = heat may have weakened the furnace brazed joints there since the = failures were always on the ends (I think). I noticed there is an = aluminum strap welded to the end tanks from top to bottom on some Harris = cores. Did yours have this? I am wondering if they are to resist the = expansion force trying to split the tank segments apart. I have built a test evap core cooler with bonded plates on the ends tied = together with threaded rod. This serves two purposes. It resists the = expansion forces and provides a thicker plate to drill & tap for AN = fittings (no welding required). Even with all the added hardware it = only weighs 5 1/2 lbs. The Fluidyne I was looking at was 12 lbs (and = still would not fit in the space available). Weight is so important to = me that I place a value of $100 per pound on weight savings. For = example, the 12 pounds I saved with aluminum landing gear cost an extra = $1200.00. This may turn out to be a total waste of time in which case I will need = a custom cooler. Ed K., what is the maximum core thickness that you can = get for oil coolers? Tracy=20 Tracy, The flluidyne coolers I am looking at using are plate type furnace = brazed units. They are rated at 150 psi. The Earl's coolers are a bit = more expensive and are rated at 175 psi with burst at 350 psi. The 3rd = gen RX7 is a plate type oil cooler. They all seem to be made the same = way as the evap cores. Evap cores can see some pretty high pressures in = service. I don't see why they couldn't work. Looks like we need to do a = failure analysis on Rusty's core. How was it mounted? Did the plumbing = exert any forces on the cooler? Perhaps weld two more aluminum straps to = the tanks to help them resist pressure forces. Trying to decide if the stock oil cooler volume is enough. If so I can = get by with the Earl's 3 in tall cooler vs the 4 in tall fluidyne. They = cost the same, but if you guys think that the stock cooler is marginal I = may just go with the extra capacity of the Fluidyne. I am partial to = Earl's products from a trust standpoint even though I know the Winston = cup guys use Fluidyne coolers for trans and diff.=20 Monty ------=_NextPart_000_0023_01C6048A.F45B9B40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Sounds like plenty of = core area to me=20 Monty. 
 
Thought I had made my = final decision=20 on the oil cooler but still having trouble getting all my design goals = to work=20 with the fluidyne cooler.  Those darn evap cores are hard to beat = for=20 weight, performance & size.  I'm back to figuring out a way to = make the=20 evap core reliable in oil cooler service. 
 
Rusty is the resident = expert on=20 failures on these things so a couple of questions for him.  =
Were the connections on = the end tanks=20 welded on?   I'm wondering if the heat may have weakened the = furnace=20 brazed joints there since the failures were always on the ends (I = think). =20 I noticed there is an aluminum strap welded to the end tanks from top to = bottom=20 on some Harris cores.  Did yours have this?  I am wondering if = they=20 are to resist the expansion force trying to split the tank segments=20 apart.
 
I have built = a test evap core=20 cooler with bonded plates on the ends tied together with threaded=20 rod.  This serves two purposes.  It resists the expansion = forces and=20 provides a thicker plate to drill & tap for AN fittings (no = welding=20 required).  Even with all the added hardware it only weighs 5 1/2=20 lbs.  The Fluidyne I was looking at was 12 lbs (and still would not = fit in=20 the space available).  Weight is so important to me that I place a = value of=20 $100 per pound on weight savings.  For example, the 12 pounds I=20 saved with aluminum landing gear cost an extra = $1200.00.
 
This may turn out to be = a total waste=20 of time in which case I will need a custom cooler.  Ed K., what is = the=20 maximum core thickness that you can get for oil coolers?
 
Tracy
 
 
Tracy,
 
The flluidyne coolers I am looking at = using are=20 plate type furnace brazed units. They are rated at 150 psi. The Earl's = coolers=20 are a bit more expensive and are rated at 175 psi with burst at 350 psi. = The 3rd=20 gen RX7 is a plate type oil cooler. They all seem to be made the same = way as the=20 evap cores. Evap cores can see some pretty high pressures in service. I = don't=20 see why they couldn't work. Looks like we need to do a failure analysis = on=20 Rusty's core. How was it mounted? Did the plumbing exert any forces on = the=20 cooler? Perhaps weld two more aluminum straps to the tanks to help them = resist=20 pressure forces.
 
Trying to decide if the stock oil = cooler volume is=20 enough. If so I can get by with the Earl's 3 in tall cooler vs the 4 in = tall=20 fluidyne. They cost the same, but if you guys think that the = stock cooler=20 is marginal I may just go with the extra capacity of the Fluidyne. I am = partial=20 to Earl's products from a trust standpoint even though I know = the=20 Winston cup guys use Fluidyne coolers for trans and = diff. 
 
Monty
 
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