X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imf22aec.mail.bellsouth.net ([205.152.59.70] verified) by logan.com (CommuniGate Pro SMTP 5.0.8) with ESMTP id 990401 for flyrotary@lancaironline.net; Sat, 18 Feb 2006 17:55:35 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.70; envelope-from=sladerj@bellsouth.net Received: from ibm67aec.bellsouth.net ([65.2.92.29]) by imf22aec.mail.bellsouth.net with ESMTP id <20060218225452.JEVG20611.imf22aec.mail.bellsouth.net@ibm67aec.bellsouth.net> for ; Sat, 18 Feb 2006 17:54:52 -0500 Received: from JSLADE ([65.2.92.29]) by ibm67aec.bellsouth.net with ESMTP id <20060218225451.HFRK1775.ibm67aec.bellsouth.net@JSLADE> for ; Sat, 18 Feb 2006 17:54:51 -0500 From: "John Slade" To: "Rotary motors in aircraft" Subject: RE: [FlyRotary] Re: Another Turbo? Date: Sat, 18 Feb 2006 17:54:43 -0500 Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_020A_01C634B4.659E5230" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_020A_01C634B4.659E5230 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Message > A real good method to reduce your risk is to assume every failure will happen to you. Not much of a stretch for me :( So, a screen at exhaust header would be a good example. We know it wouldn't last, but the concept is valuable. The concept, perhaps, but not the screen. It would disintegrate, go through the turbine wheel, parts of which could then go back through where the screen used to be :) Perhaps a little dip in your exhaust manifold would be enough to slow down the debris. Just a little bend in the tubing might be enough. Moving the turbo further from the exhaust port. Yep! The new manifold does all of these things. It would be a much more tortuous path now. With the stock manifold it was a "straight shot". Only after you've give thought to reducing the EFFECT of the failure, do you consider ways to prevent the failure. The effect of the failure was the important part. I flew home 35 miles and landed normally. I"m considering that and measuring turbo rpm dynamically. Not sure if I can do it. But it would give me huge advance notice of turbo problem. Turbo RPM would be nice, but there's really no need. The turbo map tells you what the rpm will be at any particular boost level and what rpm the unit is rated for. Ross calculated that I would still be "on the map" at 6300 rpm and 46 MAP at 18,000'. So long as I don't exceed these numbers (ie no chance in hell) the turbine rpm will remain well within limits. Using the same formulae it's possible to calculate that the stock turbo will blow right about where it does. :) What the formula doesn't allow for is bearing failure or turbine blade failure from continuous load. That seems to happen after about 10 hrs. even if you stay on the turbo map. John ------=_NextPart_000_020A_01C634B4.659E5230 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
 > A real good method to reduce your = risk is=20 to assume every failure will happen to you.  
Not=20 much of a stretch for me :(
 
So, a screen at exhaust header would be a good example. We know it = wouldn't=20 last, but the concept is valuable.  
The=20 concept, perhaps, but not the screen. It would disintegrate, go through = the=20 turbine wheel, parts of which could then go back through where the = screen used=20 to be :)
 
Perhaps a little dip in your exhaust manifold would be enough to = slow down=20 the debris. Just a little bend in the tubing might be enough.   Moving=20 the turbo further from the exhaust port.  
Yep!=20 The new manifold does all of these things. It would be a much more = tortuous path=20 now. With the stock manifold it was a "straight = shot".
 
Only after you've give thought to reducing the EFFECT of the = failure, do=20 you consider ways to prevent the failure.  
The=20 effect of the failure was the important part. I flew home 35 miles and = landed=20 normally.
 
I"m considering that and measuring turbo rpm dynamically. Not sure = if I can=20 do it. But it would give me huge advance notice of turbo problem. 
Turbo=20 RPM would be nice, but there's really no need. The turbo map tells = you what=20 the rpm will be at any particular boost level and what rpm the unit is = rated=20 for. Ross calculated that I would still be "on the map" at 6300 rpm = and 46=20 MAP at 18,000'. So long as I don't exceed these numbers (ie no chance in = hell)=20 the turbine rpm will remain well within limits. Using the same formulae = it's=20 possible to calculate that the stock turbo will blow right about where = it does.=20 :)  What the formula doesn't allow for is bearing failure or = turbine=20 blade failure from continuous load. That seems to happen after about 10 = hrs.=20 even if you stay on the turbo map.
 
John=20
------=_NextPart_000_020A_01C634B4.659E5230--