X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 20 Dec 2009 02:50:57 -0500 Message-ID: X-Original-Return-Path: Received: from sfa.gami.com ([68.89.254.162] verified) by logan.com (CommuniGate Pro SMTP 5.3c4) with ESMTP id 4031497 for lml@lancaironline.net; Sat, 19 Dec 2009 23:28:46 -0500 Received-SPF: none receiver=logan.com; client-ip=68.89.254.162; envelope-from=gwbraly@gami.com Received: from localhost (localhost.localdomain [127.0.0.1]) by sfa.gami.com (Postfix) with ESMTP id 8BEF8908 for ; Sat, 19 Dec 2009 22:28:10 -0600 (CST) Received: from gamimail1.Gami.local (mail.gami.com [10.10.10.33]) by sfa.gami.com (Postfix) with ESMTP id C637E7CC for ; Sat, 19 Dec 2009 22:28:08 -0600 (CST) Received: from gamimail1.Gami.local ([10.10.12.14]) by gamimail1.Gami.local ([10.10.12.14]) with mapi; Sat, 19 Dec 2009 22:28:13 -0600 From: George Braly X-Original-To: Lancair Mailing List X-Original-Date: Sat, 19 Dec 2009 22:28:11 -0600 Subject: RE: [LML] Re: io-550 vs. tsio-550 differences? Thread-Topic: [LML] Re: io-550 vs. tsio-550 differences? Thread-Index: Acp/K1Beg4tuUZxvQGOAbfyZetxy2wB/p1aw X-Original-Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_C273A1B35F3C6748B52EE0CC2FCEE96C0207B387589Bgamimail1Ga_" MIME-Version: 1.0 X-Virus-Scanned: by amavisd-new-2.3.2 (20050629) (Debian) at gami.com --_000_C273A1B35F3C6748B52EE0CC2FCEE96C0207B387589Bgamimail1Ga_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable >>Here's another thought: A lot of it might depend on your intended usage.= If you want to go really high (over 20K) and have maximum performance you= might want to consider getting the extra power of the TSIO-550. But if yo= u, like me, might limit altitudes to less than 20K and are more cost and fu= el economy sensitive, then a lower tech solution might be in order. I flew= for many years behind a Lycoming O-540 that was turbonormalized (C-TR-182)= and it worked quite well. It didn't have an intercooler or automatic wast= e gate - the waste gate was connected to the throttle linkage so there were= no extra levers. It was fed by a pressurized carburetor, so that doesn't = apply with a Continental. So the question is, what's wrong with using a st= andard IO-550 with a turbo and manual waste gate? The Lycomings don't both= er with a sniffle valve, so there isn't any difference between turbo, fuel = injected, or naturally aspirated engines in that regard. At 18,000 feet th= e use of an aftercooler has real, but marginal benefit, as the extra aerody= namic drag and pressure loss negate most of the charge-cooling benefit. Ju= st a thought, suggesting a KISS methodology. Gary<< Gary, Some comments. I think new designed high compression engines with compressors of any kind= should use our present state of knowledge and incorporate intercoolers - = - good intercoolers. The engine you are discussing had lower compression ratios. As someone els= e said in this same thread of messages, unless you really know what you a= re doing, you can screw up and have a very unhappy installation. Intercoolers have large benefits - - - even at sea level. I do not thin= k it is accurate to claim that intercoolers only have "marginal benefit" b= elow 18,000 feet. Here is why I think they are important: At 18,000 feet, the compressor d= ischarge temperature on a warm day can easily exceed 200dF. Without an i= ntercooler, 200dF air goes straight to your cylinders. With the TN IO-550, the induction air temperature at 30" at 18,000 feet= on a hot day will be less than 105dF. Typically 95 to 100. There is a = large difference in performance and detonation margins between 200+dF air a= nd < 105dF air. The O-540 "solution" does not really provide more fuel economy. Rather,= likely just the opposite. The TN IO-550N engine that Tornado Alley delivers to Cirrus will produce = horsepower at 0.38 to 0.39 BHp/lb-fuel/hr across an altitude and power r= ange that spans anywhere from sea level to 29000 feet and do so at 200 Hp o= r at 310 Hp, or anywhere in between. [The real world numbers for the Thie= lert diesel was about 0.36 to 0.37 BHP/lb-fuel/hr.] There is no other gener= al aviation engine installed in any fleet of aircraft that works anywhere = near that well across that broad range of operating requirements and envir= onment. 90% of the hours flown with those engines are flown between 11,000 and 18,0= 00 feet. There is a reason why Cirrus has sold ~ 900+ turbonormalized SR22 aircraft= in the last 35 months, including 15 months of some of the worst times in g= eneral aviation history. The reason is - - the systems consistently exceed the expectations of the = owners. During that period of time TAT continued to improve and refine those syste= ms. They are, today, about 15 lbs lighter than they were in 2007. They r= un cooler. They are simpler to maintain. That comes from a passion for co= ntinuous improvement. And those systems are going to become still more efficient and versatile wh= en the electronic density controllers are installed. Regards, George --_000_C273A1B35F3C6748B52EE0CC2FCEE96C0207B387589Bgamimail1Ga_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

 

>>Here's an= other thought:  A lot of it might depend on your intended usage.  If yo= u want to go really high (over 20K) and have maximum performance you might wa= nt to consider getting the extra power of the TSIO-550.  But if you, like= me, might limit altitudes to less than 20K and are more cost and fuel economy sensitive, then a lower tech solution might be in order.  I flew for m= any years behind a Lycoming O-540 that was turbonormalized (C-TR-182) and it wo= rked quite well.  It didn't have an intercooler or automatic waste gate - t= he waste gate was connected to the throttle linkage so there were no extra lev= ers.  It was fed by a pressurized carburetor, so that doesn't apply with a Continental.  So the question is, what's wrong with using a standard IO-550 with a turbo and manual waste gate?  The Lycomings don't bother with a sniffle valve, so there isn't any difference between turbo, fuel injected, or naturally aspirated engines in that regard.  At 18,000 fe= et the use of an aftercooler has real, but marginal benefit, as the extra aerodynamic drag and pressure loss negate most of the charge-cooling benefi= t.  Just a thought, suggesting a KISS methodology.

Gary<<=

 

 

Gary, 

 

Some comments.

 

I think  new designed high compression engines with compressors of any kind should use our present state of knowledge and  = ;incorporate intercoolers - - good intercoolers.

 

The engine you are discussing had lower compression ratios.&= nbsp; As someone else said  in this same thread of messages,  unless yo= u really know what you are doing,  you can screw up and have a very unha= ppy installation.

 

Intercoolers have large benefits  - - - even at sea level.    I do not think it is accurate to claim that intercoolers only have  “marginal benefit” below 18,000 fe= et.

 

Here is why I think they are important:   At 18,00= 0 feet,  the compressor discharge temperature on a warm day can easily exceed 200dF.    Without an intercooler,  200dF  a= ir goes straight to your cylinders.

 

With the  TN IO-550,  the  induction air temperature at  30” at 18,000 feet on a hot day will be less tha= n 105dF.   Typically 95 to 100.   There is a large differ= ence in performance and detonation margins between 200+dF air and < 105dF air= .   

 

The O-540 “solution” does not really provide mor= e fuel economy.     Rather, likely just the opposite.

 

The TN IO-550N engine that Tornado Alley delivers to Cirrus will   produce   horsepower at 0.38 to 0.39 BHp/lb-fuel= /hr  across an altitude and power range that spans anywhere from sea level to 29= 000 feet and do so at 200 Hp or at 310 Hp, or anywhere in between.   = [The real world numbers for the Thielert diesel was about 0.36 to 0.37 BHP/lb-fuel/hr.] There is no other general aviation engine installed in any fleet of aircraft that  works anywhere near that well across that broa= d range of operating  requirements and environment.

 

90% of the hours flown with those engines are flown between 11,000 and 18,000 feet.  

 

There is a reason why Cirrus has sold ~ 900+  turbonorm= alized SR22 aircraft in the last 35 months, including 15 months of some of the wor= st times in general aviation history.

 

The reason is - -  the systems consistently exceed the expectations of the owners.

 

During that period of time  TAT continued to improve an= d refine those systems.  They are, today,  about 15 lbs lighter tha= n they were in 2007.  They run cooler.  They are simpler to maintain.  That comes from a passion for continuous improvement. =

 

And those systems are going to become still more efficient a= nd versatile when the electronic density controllers are installed.

 

Regards,  George

 

 

 

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