X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 16 Jan 2009 16:20:40 -0500 Message-ID: X-Original-Return-Path: Received: from mail.emmett.org ([69.128.73.170] verified) by logan.com (CommuniGate Pro SMTP 5.2.11) with ESMTP id 3429688 for lml@lancaironline.net; Fri, 16 Jan 2009 12:45:36 -0500 Received-SPF: none receiver=logan.com; client-ip=69.128.73.170; envelope-from=sbuller@emmett.org X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C97802.26C12655" Subject: RE: [LML] Re: FW: [LML] Lancair IV bragging rights - drag reduction suggestions? X-Original-Date: Fri, 16 Jan 2009 12:44:58 -0500 X-Original-Message-ID: <32AF4E4BDA9A00499B3AF0C50C985EFFCB094D@oscar.emmett.org> In-Reply-To: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [LML] Re: FW: [LML] Lancair IV bragging rights - drag reduction suggestions? Thread-Index: Acl38OUip4MZEK3aSMCEAY6KnZcsxwAES6ew From: "Steve Buller" X-Original-To: "Lancair Mailing List" This is a multi-part message in MIME format. ------_=_NextPart_001_01C97802.26C12655 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Yes please.... lots of photos. Steve ________________________________ From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Art Jensen Sent: Friday, January 16, 2009 10:41 AM To: lml@lancaironline.net Subject: [LML] Re: FW: [LML] Lancair IV bragging rights - drag reduction suggestions? Fred, =20 We would all enjoy looking over your work. Please submit photos and explanations. =20 Art --- On Fri, 1/16/09, Fred Moreno wrote: From: Fred Moreno Subject: [LML] FW: [LML] Lancair IV bragging rights - drag reduction suggestions? To: lml@lancaironline.net Date: Friday, January 16, 2009, 7:01 AM =09 =09 Would you care to offer up a drag reduction prioritize list of improvements you have made ? =20 Tough question, Richard. I can not quantify a lot of the changes because I made most of them during construction so no comparison testing was possible. And I made LOT of changes.=20 =20 I believe that the biggest improvement is also the most difficult: a complete re-engineering of the engine cooling air flow pathway from modified inlets to plenum to patched air leaks, to adjustable cowl flaps that control the outlet area and exit velocity. Total time invested with endless attention to detail in this area: maybe 1000 hours. It is not recommended. Go flying instead.=20 =20 But I would recommend the following place to start: leakage of cooling air from the high pressure area above the engine. When you start looking for leaks, they are EVERYWHERE. Some are very small but numerous, some are large, all are parasitic. You want the air to flow between all the fins, full path length (no short cuts), and the oil cooler, and no where else.=20 =20 Smiley's NASA work in the 80's showed that the stock factory installation (a turbo Piper Aztec with 250 HP Lycoming engines) of baffles, rubber and sheet metal typically leaked 50% of the required cooling flow. That is, if you need 100% to cool the engine, 150% was going into the inlets and out the outlets, pure waste in momentum drag. =20 Most installations I have seen look OK on first blush, but with very close inspection, virtually all leak like sieves. It takes extreme attention to detail and a lot of patience to minimize the leakage. But the benefits of fixing are substantial: reduced drag, and much cooler operating temperatures. =20 =20 When racing with Brent Regan and in studying many other aircraft and collecting anecdotal data from many, I concluded that a well built, smooth, tight fitting Lancair IV had little room for improvement behind the firewall, so most of my work was in front of it. =20 =20 If there is enough interest, I will develop a picture catalog of all the drag reduction modifications I have made together with some descriptive words so other builders can pick and choose what they want to use. Some changes are easy. Some are very time consuming. And because I started with many of the mods in place, I can not separate out the individual benefits. But if enough people are interested, I will compile a catalog and let Marv put it into the archives.=20 =20 Fred Moreno=20 =20 -----Original Message----- From: marv@lancair.net [mailto:marv@lancair.net]=20 Sent: Friday, 16 January 2009 3:34 AM To: lml Subject: Re: [LML] Lancair IV bragging rights=20 =20 Posted for "Richard T. Schaefer" :=20 =20 Sounds great .=20 =20 Would you care to offer up a drag reduction prioritize list of improvements=20 you have made ?=20 =20 =20 > Now that summer is well established Down Under, I was able to conduct some=20 > more flight testing. The air is smooth, winds gentle, and the bugs have=20 ------_=_NextPart_001_01C97802.26C12655 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable
Yes please.... lots of = photos.
Steve

From: Lancair Mailing List=20 [mailto:lml@lancaironline.net] On Behalf Of Art = Jensen
Sent:=20 Friday, January 16, 2009 10:41 AM
To:=20 lml@lancaironline.net
Subject: [LML] Re: FW: [LML] Lancair IV = bragging=20 rights - drag reduction suggestions?

Fred,
 
We would all enjoy looking over your work.  Please = submit photos=20 and explanations.
 
Art

--- On Fri, 1/16/09, Fred Moreno=20 <fredmoreno@optusnet.com.au> wrote:
From:=20 Fred Moreno <fredmoreno@optusnet.com.au>
Subject: [LML] = FW:=20 [LML] Lancair IV bragging rights - drag reduction = suggestions?
To:=20 lml@lancaironline.net
Date: Friday, January 16, 2009, 7:01 = AM

  Would you care to = offer up a=20 drag reduction prioritize list of = improvements

  you have made=20 ?

 

Tough question, Richard.  I can = not=20 quantify a lot of the changes because I made most of them during = construction so no comparison testing was possible.  And I=20 made  LOT of changes.

 

I believe that the biggest improvement = is also=20 the most difficult: a complete re-engineering of the engine = cooling air=20 flow pathway from modified inlets to plenum to patched air = leaks, to=20 adjustable cowl flaps that control the outlet area and exit = velocity.=20   Total time invested with endless attention to detail = in this=20 area: maybe 1000 hours.  It is not recommended.  Go = flying=20 instead.

 

But I would recommend the following = place to=20 start: leakage of cooling air from the high pressure area above = the=20 engine.  When you start looking for leaks, they are=20 EVERYWHERE.  Some are very small but numerous, some are = large, all=20 are parasitic.  You want the air to flow between all the = fins, full=20 path length (no short cuts), and the oil cooler, and no where = else.=20

 

Smiley's NASA work in the 80's showed = that the=20 stock factory installation (a turbo Piper Aztec with 250 HP = Lycoming=20 engines) of baffles, rubber and sheet metal typically leaked 50% = of the=20 required cooling flow.  That is, if you need 100% to cool = the=20 engine, 150% was going into the inlets and out the outlets, pure = waste=20 in momentum drag. 

 

Most installations I have seen look OK = on first=20 blush, but with very close inspection, virtually all leak like=20 sieves.  It takes extreme attention to detail and a lot of = patience=20 to minimize the leakage.  But the benefits of fixing are=20 substantial: reduced drag, and much cooler operating = temperatures. =20

 

When racing with Brent Regan and in = studying=20 many other aircraft and collecting anecdotal data from many, I = concluded=20 that a well built, smooth, tight fitting Lancair IV had little = room for=20 improvement behind the firewall, so most of my work was in front = of=20 it. 

 

If there is enough interest, I will = develop a=20 picture catalog of all the drag reduction modifications I have = made=20 together with some descriptive words so other builders can pick = and=20 choose what they want to use.  Some changes are easy.  = Some=20 are very time consuming.  And because I started with many = of the=20 mods in place, I can not separate out the individual = benefits.  But=20 if enough people are interested, I will compile a catalog and = let Marv=20 put it into the archives.

 

Fred Moreno

 

-----Original Message-----
From:=20 marv@lancair.net [mailto:marv@lancair.net]
Sent: = Friday, 16 January 2009 = 3:34 AM
To: = lml
Subject: Re:=20 [LML] Lancair IV bragging rights

 

Posted for "Richard T. Schaefer"=20 <schaefer@rts-services.com>:

 

  Sounds great .

 

  Would you care to offer up a = drag=20 reduction prioritize list of improvements

  you have made ?

 

 

> Now that summer is well = established Down=20 Under, I was able to conduct some

> more flight testing.  The = air is=20 smooth, winds gentle, and the bugs have

=

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