X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 27 Jun 2005 18:18:16 -0400 Message-ID: X-Original-Return-Path: Received: from systems3.net ([68.14.236.16] verified) by logan.com (CommuniGate Pro SMTP 4.3.5) with ESMTPS id 1023916 for lml@lancaironline.net; Mon, 27 Jun 2005 17:37:38 -0400 Received-SPF: none receiver=logan.com; client-ip=68.14.236.16; envelope-from=cberland@systems3.net Received: from systems0d3b724 ([192.168.1.81]) by systems3.net (8.13.4/8.13.4/Debian-1) with SMTP id j5RLanfk015843 for ; Mon, 27 Jun 2005 14:36:49 -0700 X-Original-Message-ID: <01dd01c57b60$267bc690$5101a8c0@systems0d3b724> From: "Craig Berland" X-Original-To: "Lancair Mail List" Subject: [LML] On Boosting Engines, Stressing Crankshaft and TBO X-Original-Date: Mon, 27 Jun 2005 14:35:29 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_01DA_01C57B25.770EEB40" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1506 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1506 This is a multi-part message in MIME format. ------=_NextPart_000_01DA_01C57B25.770EEB40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Alain said: When boosting engines beyond their design output, does = Performance Engines take into account the significant stresses imposed = on the crankshaft (and other stressed parts, for that matter)? Walter Atkinson said: Alain, I think you're on the right track. There = has been compelling evidence shown that the Lycoming crankshaft problem = is one of design, not manufacture. I do not have any first hand knowledge of the Lycoming fiasco, therefore = I will default to Walter as I am confident he is correct. However, I = will point out there are a lot of factors that go into making a reliable = engine besides crankshaft ultimate strength. One important item is: How = do you fly the engine? As Water has correctly pointed out in the = past...where do you develop peak cylinder pressure. Is the engine well = balanced? Are other components such as pistons up to the task? I just = returned Saturday afternoon from a visit to Performance Engines relative = to them building a 400 hp TSIO 550 for my IV-P. I was very impressed = with Ron Monson and Performance Engines. Back to the crankshaft....General Motors has a very sophisticated = computer finite element model program for designing crankshafts. They = still TEST engines. The only way to test engines is on a dyno or in our = case in a plane. In my mind, the necessary test time has been = accomplished on the TSIO 550 to make me comfortable with the engine I = want. There are a lot of these engine flying and the same engine is = being raced at 600 to 700 hp. The racing alone does not make a 400 hp = version acceptable, however the ultimate crank strength is pretty good. = The one thing I am 100% confident in is.....if I was to buy a "new" TSIO = 550 engine, I would send it to someone like Performance Engines to be = "fixed". If you are not comfortable with a higher hp engine, then go = with a "high quality" built standard hp version. Whatever you choose, I = don't think you should need a top overhaul in 800 hrs let alone in 400 = hrs. I believe a good builder will warranty his build unless you are = calling the design shots or racing. My direct answer to your question is.....the testing has been done and = will continue to be done by those who buy and fly these high hp engines. = On the other hand, just because the "Factory" says its OK does not = necessarily make it so. The Lycoming fiasco was do to standard engines = going south. But I also believe you have to be even more careful when = venturing away from the norm. Decide what interests you and talk to = those that fly them. If you want something totally unique, then you are = the man....you take the initial risk. Craig Berland ------=_NextPart_000_01DA_01C57B25.770EEB40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Alain said:=20 When boosting engines beyond their design output, does Performance = Engines take=20 into account the significant stresses imposed on the crankshaft (and = other=20 stressed parts, for that matter)?
Walter=20 Atkinson said: Alain,  I think you're on the right = track. =20 There has been compelling evidence shown that the Lycoming = crankshaft=20 problem is one of design, not manufacture.
 
 
I do not have any first hand knowledge of the Lycoming fiasco, = therefore I=20 will default to Walter as I am confident he is correct.  However, I = will=20 point out there are a lot of factors that go into making a reliable = engine=20 besides crankshaft ultimate strength. One important item is: How do you = fly the=20 engine?  As Water has correctly pointed out in the past...where do = you=20 develop peak cylinder pressure.  Is the engine well balanced?  = Are=20 other components such as pistons up to the task?  I just returned = Saturday=20 afternoon from a visit to Performance Engines relative to them building = a 400 hp=20 TSIO 550 for my IV-P.  I was very impressed with Ron Monson and = Performance=20 Engines.
 
Back to the crankshaft....General Motors has a very sophisticated = computer=20 finite element model program for designing crankshafts.  They still = TEST=20 engines.  The only way to test engines is on a dyno or in our case = in a=20 plane.  In my mind, the necessary test time has been accomplished = on the=20 TSIO 550 to make me comfortable with the engine I want.  There are = a lot of=20 these engine flying and the same engine is being raced at 600 to 700 = hp. =20 The racing alone does not make a 400 hp version acceptable, however = the=20 ultimate crank strength is pretty good.  The one thing I = am 100%=20 confident in is.....if I was to buy a "new" TSIO 550 engine, I would = send it to=20 someone like Performance Engines to be "fixed".  If you are not = comfortable=20 with a higher hp engine, then go with a "high quality" built standard hp = version.  Whatever you choose, I don't think you should need a top = overhaul=20 in 800 hrs let alone in 400 hrs.  I believe a good builder will = warranty=20 his build unless you are calling the design shots or racing.
 
My direct answer to your question is.....the testing has been = done and=20 will continue to be done by those who buy and fly these high hp = engines. =20 On the other hand, just because the "Factory" says its OK does not = necessarily=20 make it so. The Lycoming fiasco was do to standard engines going = south.=20  But I also believe you have to be even more careful when venturing = away=20 from the norm.  Decide what interests you and talk to those that = fly=20 them.  If you want something totally unique, then you are the = man....you=20 take the initial risk.
Craig Berland

 
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