Return-Path: Received: from pop3.olsusa.com ([63.150.212.2] verified) by logan.com (CommuniGate Pro SMTP 3.5b3) with ESMTP id 860666 for rob@logan.com; Sun, 02 Sep 2001 14:09:40 -0400 Received: from qbert.gami.com ([65.66.11.38]) by pop3.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-71866U8000L800S0V35) with ESMTP id com for ; Sun, 2 Sep 2001 11:40:41 -0400 Received: by QBERT with Internet Mail Service (5.5.2650.21) id ; Sun, 2 Sep 2001 10:56:59 -0500 Message-ID: <52548863F8A5D411B530005004759A93012B38@QBERT> From: George Braly To: "'lancair.list@olsusa.com'" Subject: RE: TSIO550 Engine Modifications Date: Sun, 2 Sep 2001 10:56:52 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" X-Mailing-List: lancair.list@olsusa.com Reply-To: lancair.list@olsusa.com <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> Jack, Having recently been operating TIO-540 J2BD (350Hp stock ) and TIO-540 AE2A (350Hp stock) and Turbo normalized IO-550s in a very highly instrumented environment, I agree with almost all of your concerns. BUT... let me note that you can get horsepower in different ways and it turns out, there is a lot to be gained by HOW you get the horsepower and a lot of problems can be avoided by being careful about HOW you get the horsepower. For example, I currently operate the TN-IO-550 engine at cruise at approximately 260-265 Hp on a routine basis. After doing that for 800 hours on a set of Millennium jugs, I tore down the engine (bottom end was at 1800 hours) and inspected the cylinders very very carefully. The cylinder barrels were all within NEW limits (note, NOT just service limits, but new limits) and this included the choke area! Valve guides etc were all in excellent condition. So... given your accurate observations about the traditional service life of the TSIO-550 engines, how the heck did I do this? Consider that the real problem is not the *MEAN* pressure in the cylinders (mean pressure times displacement times RPM times a constant = Hp) but the critical issue is the magnitude of the cylinder combustion pressure at its peak value right after TDC when the piston is just starting down. It is possible to make, say 350 Hp with the peak pressures at 1100 PSI and it is also possible to make 350 HP with the peak pressures at only 950 PSI.... but with the mean pressures the same in each case. The difference in the longevity and temperature issues for the engine are rather startling. Using our PRISM (Pressure Reactive Intelligent Spark Management) system we are able to do this almost effortlessly. I have been able to operate these engines at 375 to 400 Hp with the peak cylinder pressures at or below the values traditionally seen with the engines in the stock configuration operating at 350 Hp. So, yes, it is possible to develop these engines to deliver Hp up in the 375 to 400 Hp range without grinding away on the jugs etc, all of which have problems as you point out. And yes, you are very correct that calibrating the Dyno is critical and it is easy to cheat on that. And your concern about the durability issues are spot on. Nevertheless, I do point out that we have demonstrated very good success with very high continuous horsepower output (260-265) with all of the CHTs held below 380F at altitude on hot days and we have done this for extended intervals with almost no detectable wear on the critical mechanical components. This capability has been reproduced on a number of engines that are accumulating a lot of time at a very rapid rate right now with no problems yet noted. Regards, George Braly at GAMI -----Original Message----- From: Epijk@aol.com [mailto:Epijk@aol.com] Sent: Friday, August 31, 2001 2:34 PM To: lancair.list@olsusa.com Subject: Re: TSIO550 Engine Modifications <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> In a message dated 8/30/2001 8:23:08 PM Pacific Daylight Time, AVIDWIZ@aol.com writes: << The benefit is increased horsepower (400 HP) and a smoother engine. >> Just some thoughts to contemplate re the subject matter: For the sake of discussion, lets conjecture that they REALLY CAN increase the power output to 400 HP. Since this is not a geared engine, they would >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML website: http://www.olsusa.com/mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>