Return-Path: Received: from [65.54.168.120] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.3c1) with ESMTP id 722572 for flyrotary@lancaironline.net; Wed, 09 Feb 2005 15:43:24 -0500 Received-SPF: pass receiver=logan.com; client-ip=65.54.168.120; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Wed, 9 Feb 2005 12:42:00 -0800 Message-ID: Received: from 4.174.1.184 by BAY3-DAV16.phx.gbl with DAV; Wed, 09 Feb 2005 20:41:58 +0000 X-Originating-IP: [4.174.1.184] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Oil leak Date: Wed, 9 Feb 2005 15:41:55 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00FB_01C50EBD.E22A06A0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MimeOLE: Produced By MSN MimeOLE V9.10.0009.2900 Seal-Send-Time: Wed, 9 Feb 2005 15:41:55 -0500 X-OriginalArrivalTime: 09 Feb 2005 20:42:00.0635 (UTC) FILETIME=[CE0140B0:01C50EE7] This is a multi-part message in MIME format. ------=_NextPart_000_00FB_01C50EBD.E22A06A0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Don't be too quick to make assumptions about where leaking oil goes = under a cowl. The airflow under the cowl is faster and in more = directions than you might think. It carries oil into the most unexpected = places. Sometimes the source is obvious and sometimes not. As always = in this endeavor, there are very few absolute rules.=20 Tracy ----- Original Message -----=20 From: John Slade=20 To: Rotary motors in aircraft=20 Sent: Wednesday, February 09, 2005 1:19 PM Subject: [FlyRotary] Oil leak Hi Guys, I've been chasing an oil leak for a while now. It only happens when = the engine is running. When I get back from a 20 minute flight the cowl = has oil streaks down the outside, everything under the cowl has an oil = film on it, and the turbo is seriously smokin'. I could probably make a = similar mess by spraying about 1/2 cup of oil at the cowl and engine. Today I took the plane up and down the runway a couple of times and = did a couple of runups with the cowl off. I seem to be a little down on = power - (3950 instead of 4050 on static). When I got back the mount = plate below the turbo had fresh oil on it and I could see air bubbling = through this oil at the joint of the mount plate and the engine, just by = the turbo. See attached picture with arrow. In fact the entire join = between the engine and the plate on the right (turbo) side seems wet = with oil and there's another pool at the front which I don't think = migrated from the back.=20 I get the feeling that this "bubbling" might become a fine jet of oil = which points directly at the turbo when the engine's running, otherwise = I don't see how oil could get up into the turbo housing and smoke like = it does. I'm trying to understand why there might be pressure here. The = breather is definitely not blocked, and in fact, on this particular run, = I'd even left the dipstick out. Could the bubbling air be a compression = leak from the join between the rotor hosing and the backplate? My oil = level is maybe 1/4 - 1/2 inch below the level of the mount plate and the = plane was on a slight grade making the back lower. The bubbling stopped = after a few minutes and did not return when we turned the prop.=20 I'm resigned to pulling the lower cowl, sump and sump plate and = redoing the RTV join (again), but I'm wondering - should there be = pressure here? Is there some other problem causing this. Am I overfull = with oil? Could the turbo oil return be "landing" on the mount plate, = then running back along the join? I'm planning a compression test next = time I go down to the hangar.=20 Any other thoughts or suggestions? Regards, John (13.9 hrs and holding) >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_000_00FB_01C50EBD.E22A06A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Don't be too quick to make assumptions about = where leaking oil=20 goes under a cowl.  The airflow under the cowl is faster and in = more=20 directions than you might think. It carries oil into the most unexpected = places.  Sometimes the source is obvious and sometimes not.  = As always=20 in this endeavor, there are very few absolute = rules. 
 
Tracy
----- Original Message -----
From: John=20 Slade
To: Rotary motors in = aircraft
Sent: Wednesday, February 09, = 2005 1:19=20 PM
Subject: [FlyRotary] Oil = leak

Hi=20 Guys,
I've=20 been chasing an oil leak for a while now. It only happens when the = engine is=20 running. When I get back from a 20 minute flight the cowl has oil = streaks down=20 the outside, everything under the cowl has an oil film on it, and = the=20 turbo is seriously smokin'. I could probably make a similar mess = by=20 spraying about 1/2 cup of oil at the cowl and = engine.
 
Today I took the plane up and down the runway a couple of = times and did=20 a couple of runups with the cowl off. I seem to be a little down on = power -=20 (3950 instead of 4050 on static). When I got back the mount plate = below the=20 turbo had fresh oil on it and I could see air bubbling through this = oil at the=20 joint of the mount plate and the engine, just by the turbo. See = attached=20 picture with arrow. In fact the entire join between the engine and the = plate=20 on the right (turbo) side seems wet with oil and there's another pool = at the=20 front which I don't think migrated from the back.
 
I=20 get the feeling that this "bubbling" might become a fine jet of oil = which=20 points directly at the turbo when the engine's running, otherwise = I don't=20 see how oil could get up into the turbo housing and smoke like it = does.=20  I'm trying to understand why there might be pressure here. The = breather=20 is definitely not blocked, and in fact, on this particular run, I'd = even left=20 the dipstick out. Could the bubbling air be a compression leak from = the join=20 between the rotor hosing and the backplate?  My oil level is = maybe 1/4 -=20 1/2 inch below the level of the mount plate and the plane was on a = slight=20 grade making the back lower. The bubbling stopped after a few minutes = and did=20 not return when we turned the prop.
 
I'm=20 resigned to pulling the lower cowl, sump and sump plate and redoing = the RTV=20 join (again), but I'm wondering - should there be pressure here? Is = there some=20 other problem causing this. Am I overfull with oil?  Could the = turbo oil=20 return be "landing" on the mount plate, then running back along the = join? I'm=20 planning a compression test next time I go down to the hangar.=20
 
Any=20 other thoughts or suggestions?
 
Regards,
John=20 (13.9 hrs and holding)
>>  = Homepage: =20 http://www.flyrotary.com/
>>  Archive:  =20 = http://lancaironline.net/lists/flyrotary/List.html
= ------=_NextPart_000_00FB_01C50EBD.E22A06A0--