Return-Path: Received: from smtp109.mail.sc5.yahoo.com ([66.163.170.7] verified) by logan.com (CommuniGate Pro SMTP 4.2.5) with SMTP id 567843 for flyrotary@lancaironline.net; Tue, 14 Dec 2004 20:09:44 -0500 Received-SPF: none receiver=logan.com; client-ip=66.163.170.7; envelope-from=prvt_pilot@yahoo.com Received: from unknown (HELO stevehome) (prvt?pilot@24.136.229.34 with login) by smtp109.mail.sc5.yahoo.com with SMTP; 15 Dec 2004 01:09:16 -0000 Reply-To: From: "Steve Brooks" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] RV-3 post-mortem Date: Tue, 14 Dec 2004 20:09:08 -0500 Message-ID: <001f01c4e242$ade28900$6b01a8c0@workgroup.com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0020_01C4E218.C50E07A0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook CWS, Build 9.0.6604 (9.0.2911.0) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1441 Importance: Normal In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_0020_01C4E218.C50E07A0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit MessageRusty, I would think that the bearings would be ruined while running without oil, but you'll know more when you tear it down for inspection. It certainly could have been much worse. At least you and the plane can be reused. Steve Brooks -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On Behalf Of Russell Duffy Sent: Tuesday, December 14, 2004 5:05 PM To: Rotary motors in aircraft Subject: [FlyRotary] RV-3 post-mortem Greetings, Well, I got the plane hauled back to the hanger, and managed to find the problem. I had fully expected to find the oil cooler (evap core) split at one of the seams in the tank, but I couldn't see a thing wrong with it. After wiping off the oil, and checking all the oil components, I still couldn't see anything wrong. At that point, I drained the pan, and only measured 1/3 quart. This is clearly below the oil pickup, which is at least a half inch off the bottom of the pan due to the sandwich mount plate. I proceeded to remove the oil cooler, and inline filter. The filter wasn't plugged, or collapsed, though there are some flakes of something in it. Even on the workbench, the cooler looks absolutely fine, but it isn't. Blowing through it demonstrates a definite leak at one of the seams on the tank. If you look at the way these are constructed, the core is made up of a number of layers, stacked together like slices of bread. To close up the open ends of the tanks, there's about a 1/16" aluminum plate brazed at the end of the tanks. The seam between this plate, and the main part of the core is what leaked on both of my oil cooler cores. The attached pictures show an old core that Ed sent me to do some testing with a couple years ago. It had developed a leak from what he believed to be too much strain/vibration on the hoses. Both of my oil cooler evap cores leaked at this same seam. The latest one was on the end of the tank with the fitting that I welded on. You could suppose that the welding process overheated the seam, and caused it to leak, however, it sure took it's time (at least 10 hours for this one, and about 30 hours for the first one) deciding to leak. You could also suppose that the strain on the hose caused fatigue. My oil hose is long, and has lots of room to flex. I just can't imagine that putting any strain on the oil cooler fitting. The first leaking oil core happened on the end without the welded fitting, though that one was dented in. In other words, welding, or strain from a fitting couldn't have been the cause in that case. I find it too much of a coincidence that my two water cores have not had any problems, yet both of the cores I've tried on oil have leaked at the same point of construction. Of course Ed did have a water core that leaked at the same point. Bottom line is that this seam seems to be the weak point of these cores. I can't explain exactly why they're failing, but I have to conclude that they aren't so robust as I'd like them to be. I'd be interested to know if this is where they commonly leak on cars as well. As for the engine, all 6 rotor faces seem to have even compression when turned by hand. Unfortunately, I'd have to say that the compression is considerably less than it used to be. The engine will definitely have to come apart. As for the plane, I've already received one email asking if I want to sell it, so I might pursue that. As you know, only a couple weeks ago, I was saying that I planned to sell the RV-3, and transplant the engine into an RV-7. Well, the plane's apart, and I would end up putting a significant amount of time into getting it back in the air. With that in mind, I'm thinking that it might be just as well to go ahead and sell the airframe now. Haven't decided for sure, but I could see getting the Slingshot back together in fairly short order with the 912S, then either starting on a single rotor conversion for the Slingshot, or starting on an RV-7. Cheers, Rusty (undecided) ------=_NextPart_000_0020_01C4E218.C50E07A0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
Rusty,
I=20 would think that the bearings would be ruined while running without oil, = but=20 you'll know more when you tear it down for = inspection.
 
It=20 certainly could have been much worse.  At least you and the plane = can be=20 reused.
 
Steve=20 Brooks
 
-----Original Message-----
From: Rotary motors in = aircraft=20 [mailto:flyrotary@lancaironline.net]On Behalf Of Russell=20 Duffy
Sent: Tuesday, December 14, 2004 5:05 PM
To: = Rotary=20 motors in aircraft
Subject: [FlyRotary] RV-3=20 post-mortem

Greetings,
 
Well, I got = the plane=20 hauled back to the hanger, and managed to find the problem.  I = had fully=20 expected to find the oil cooler (evap core) split at one of the seams = in the=20 tank, but I couldn't see a thing wrong with it.  After wiping off = the=20 oil, and checking all the oil components, I still couldn't see = anything=20 wrong. 
 
At that = point, I drained=20 the pan, and only measured 1/3 quart.  This is clearly below = the oil=20 pickup, which is at least a half inch off the bottom of the pan due to = the=20 sandwich mount plate.  I proceeded to remove the oil cooler, and = inline=20 filter.  The filter wasn't plugged, or collapsed, though there = are some=20 flakes of something in it.   Even on the workbench, the = cooler looks=20 absolutely fine, but it isn't.  Blowing through it demonstrates a = definite leak at one of the seams on the tank.  =
 
If you look = at the way=20 these are constructed, the core is made up of a number of layers, = stacked=20 together like slices of bread.  To close up the open ends of the = tanks,=20 there's about a 1/16" aluminum plate brazed at the end of the = tanks.  The=20 seam between this plate, and the main part of the core is what leaked = on both=20 of my oil cooler cores.   The attached pictures show an old = core=20 that Ed sent me to do some testing with a couple years ago.  It = had=20 developed a leak from what he believed to be too much strain/vibration = on the=20 hoses. 
 
Both of my = oil cooler=20 evap cores leaked at this same seam.  The latest one was on the = end of=20 the tank with the fitting that I welded on.  You could suppose = that the=20 welding process overheated the seam, and caused it to leak, however, = it sure=20 took it's time (at least 10 hours for this one, and about 30 hours for = the=20 first one) deciding to leak.  You could also suppose that the = strain on=20 the hose caused fatigue.  My oil hose is long, and has lots of = room to=20 flex.  I just can't imagine that putting any strain on the oil = cooler=20 fitting.  The first leaking oil core happened on the end = without the=20 welded fitting, though that one was dented in.   In other = words,=20 welding, or strain from a fitting couldn't have been the cause in that = case.  
 
I find it too = much of a=20 coincidence that my two water cores have not had any problems, = yet both=20 of the cores I've tried on oil have leaked at the same = point of=20 construction.  Of course Ed did have a water core that leaked at = the same=20 point.  Bottom line is that this seam seems to be the weak point = of these=20 cores.  I can't explain exactly why they're failing, but I have = to=20 conclude that they aren't so robust as I'd like them to be.  = I'd be=20 interested to know if this is where they commonly leak on cars as=20 well.  
 
As for the = engine, all=20 6 rotor faces seem to have even compression when turned by = hand. =20 Unfortunately, I'd have to say that the compression is = considerably less=20 than it used to be.  The engine will definitely have to come=20 apart.  
 
As for = the plane,=20 I've already received one email asking if I want to sell it, so I = might=20 pursue that.  As you know, only  a couple weeks ago, I was = saying=20 that I planned to sell the RV-3, and transplant the engine into=20 an RV-7.  Well, the plane's apart, and I would end up = putting a=20 significant amount of time into getting it back in the air.  With = that in=20 mind, I'm thinking that it might be just as well to go ahead and sell = the=20 airframe now.  Haven't decided for sure, but I could see getting=20 the Slingshot back together in fairly short order with the 912S,=20 then either starting on a single rotor conversion for = the Slingshot,=20 or starting on an RV-7.  
 
Cheers,
Rusty=20 (undecided)   
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