X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 21 Apr 2006 21:56:38 -0400 Message-ID: X-Original-Return-Path: Received: from smtp109.sbc.mail.mud.yahoo.com ([68.142.198.208] verified) by logan.com (CommuniGate Pro SMTP 5.0.9) with SMTP id 1076005 for lml@lancaironline.net; Fri, 21 Apr 2006 19:44:36 -0400 Received-SPF: none receiver=logan.com; client-ip=68.142.198.208; envelope-from=elippse@sbcglobal.net Received: (qmail 90539 invoked from network); 21 Apr 2006 23:37:11 -0000 Received: from unknown (HELO Computerroom) (elippse@sbcglobal.net@70.237.146.154 with login) by smtp109.sbc.mail.mud.yahoo.com with SMTP; 21 Apr 2006 23:37:10 -0000 X-Original-Message-ID: <000501c6659c$85183ea0$9a92ed46@Computerroom> From: "Paul Lipps" X-Original-To: Subject: Why a Lancair X-Original-Date: Fri, 21 Apr 2006 16:37:10 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0002_01C66561.D63CCDE0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2869 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2869 This is a multi-part message in MIME format. ------=_NextPart_000_0002_01C66561.D63CCDE0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable For me, a Lancair is both beautiful and fast. Many put in thousands of = hours sanding and painting to enhance their plane's beauty, but if they = would put in one-tenth that number of hours designing and building an = efficient and low-drag cooling system, they would have the best of both = worlds. I have seen some of the most beautiful birds, on the outside, = have such horrible gunk for a cooling system. Don't use scat tubing = anywhere; its pressure drop is horrendous. Put in a small blast tube for = the alternator, and also for the fuel pump and gascolator to prevent = vapor lock. Wrap the cylinders with fiberglass or carbon fiber to keep = the air in close contact with the fins. This increases your cooling = efficiency and so requires smaller inlets with less drag. You can use = Safety Poxy for this, or RTV, or hi-temp epoxy from someone like = Master-Bond. Are your cylinders running less than 360F? Too cool! Close = down your inlets! You want the cylinders at about 385F for best = efficiency. These aircooled cylinders have incredible piston clearances. = They are designed to give the best performance in the 360-400 range. Use = it! At the bottom of the cylinder, don't have a sharp edge on the baffle = but roll it outboard at least 180 deg to keep the air from separating as = it emerges. Cooling air that flows past wires, tubes, motor mount, and = the sharp edge at the bottom of the firewall to get out of the cowling = requires a greater low pressure to extract it - drag! Put cooling air = outlets right below the cylinders or duct it out. For some reason the = inlet and plenum are well designed, and then it's just assumed the air = will find its way out! Don't steal cylinder cooling air from the upper = plenum to feed the oil cooler. Feed it with a separate inlet with a = diverging duct, then give it a converging duct and outlet pointing to = the rear; don't just dump it into the area ahead of the firewall. Don't = use the so-called "NACA" duct unless you understand its pressure = recovery vs duct flow ratio. It's just one of three of the family of = "submerged" ducts. Its proper name is divergent curved-wall submerged = duct. There is also straight-wall divergent submerged duct and a = parallel-wall submerged duct. Is the outer lip of your NACA duct sharp = or is it rounded and shaped like an inverted leading edge? If it's = sharp, it's wrong! Do you have intercoolers? Look what Darryl did with = his. He exhausts each of them through a converging nozzle on top of the = cowling facing the rear. Do you know how a jet engine works? You add = heat to air which increases its energy and then employ this added energy = to increase the exhaust velocity to create thrust. Your cylinder cooling = fins, oil cooler, and intercoolers are, in effect, little jet engines. = Use that heat to reduce your cooling drag. Use the exhaust to help = extract the cooling air. Why just pump that 1/3 of the fuel's energy = overboard. A properly designed augmenter will decrease the xhaust outlet = temperature and also slightly muffle the exhaust sound without having = resonant amplification. There are other ways to make an augmenter than = the tube variety. Charley Airesman in his Sub-powered EZ uses a = tube-type augmenter to pull air through his radiator. No overheating on = the ground in his EZ! 'Nough said! ------=_NextPart_000_0002_01C66561.D63CCDE0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
For me, a Lancair is both beautiful and fast. = Many put in=20 thousands of hours sanding and painting to enhance their plane's beauty, = but if=20 they would put in one-tenth that number of hours designing and building = an=20 efficient and low-drag cooling system, they would have the best of both = worlds.=20 I have seen some of the most beautiful birds, on the outside, have such = horrible=20 gunk for a cooling system. Don't use scat tubing anywhere; its pressure = drop is=20 horrendous. Put in a small blast tube for the alternator, = and=20 also for the fuel pump and gascolator to prevent vapor lock. Wrap = the=20 cylinders with fiberglass or carbon fiber to keep the air in close = contact with=20 the fins. This increases your cooling efficiency and so requires smaller = inlets=20 with less drag. You can use Safety Poxy for this, or RTV, or hi-temp = epoxy from=20 someone like Master-Bond.  Are your cylinders running less = than 360F?=20 Too cool! Close down your inlets! You want the cylinders at about = 385F for=20 best efficiency. These aircooled cylinders have incredible piston = clearances.=20 They are designed to give the best performance in the 360-400 range. Use = it! At the bottom of the cylinder, don't have a sharp edge on the = baffle=20 but roll it outboard at least 180 deg to keep the air from separating as = it=20 emerges. Cooling air that flows past wires, tubes, motor mount, and the = sharp=20 edge at the bottom of the firewall to get out of the cowling = requires=20 a greater low pressure to extract it - drag! Put cooling air outlets = right below=20 the cylinders or duct it out. For some reason the inlet and plenum are = well=20 designed, and then it's just assumed the air will find its way = out! Don't=20 steal cylinder cooling air from the upper plenum to feed the oil = cooler.=20 Feed it with a separate inlet with a diverging duct, then give it a = converging=20 duct and outlet pointing to the rear; don't just dump it into the area = ahead of=20 the firewall. Don't use the so-called "NACA" duct unless you understand = its=20 pressure recovery vs duct flow ratio. It's just one of three of the = family of=20 "submerged" ducts. Its proper name is = divergent curved-wall submerged=20 duct. There is also straight-wall divergent submerged duct and a = parallel-wall=20 submerged duct. Is the outer lip of your NACA duct sharp or is it = rounded=20 and shaped like an inverted leading edge? If it's sharp, it's=20 wrong! Do you have intercoolers? Look what Darryl did with his. He = exhausts=20 each of them through a converging nozzle on top of the cowling = facing the=20 rear. Do you know how a jet engine works? You add heat to air which = increases=20 its energy and then employ this added energy to increase the exhaust = velocity to=20 create thrust. Your cylinder cooling fins, oil cooler, and intercoolers = are, in=20 effect, little jet engines. Use that heat to reduce your cooling = drag. Use=20 the exhaust to help extract the cooling air. Why just pump that 1/3 of = the=20 fuel's energy overboard. A properly designed augmenter will decrease the = xhaust outlet temperature and also slightly muffle the exhaust = sound=20 without having resonant amplification. There are other ways to make an = augmenter=20 than the tube variety. Charley Airesman in his Sub-powered EZ uses a = tube-type=20 augmenter to pull air through his radiator. No overheating on the = ground in=20 his EZ! 'Nough said!
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