X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 09 Jul 2007 21:05:24 -0400 Message-ID: X-Original-Return-Path: Received: from ironport5.liveoakmail.com ([216.110.12.21] verified) by logan.com (CommuniGate Pro SMTP 5.1.10) with ESMTP id 2167697 for lml@lancaironline.net; Mon, 09 Jul 2007 17:07:03 -0400 Received-SPF: none receiver=logan.com; client-ip=216.110.12.21; envelope-from=walter@advancedpilot.com X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ao8CABZAkkZAMf4V/2dsb2JhbACCYg X-IronPort-AV: E=Sophos;i="4.16,518,1175490000"; d="scan'208,217";a="21168503" Received: from rs5.liveoakhosting.com (HELO secure5.liveoakhosting.com) ([64.49.254.21]) by ironport5.liveoakmail.com with ESMTP; 09 Jul 2007 16:06:25 -0500 Received: (qmail 8653 invoked from network); 9 Jul 2007 16:06:25 -0500 Received: from ip68-108-233-213.br.br.cox.net (HELO ?10.0.1.2?) (68.108.233.213) by rs5.liveoakhosting.com with (AES128-SHA encrypted) SMTP; 9 Jul 2007 16:06:25 -0500 Mime-Version: 1.0 (Apple Message framework v752.3) In-Reply-To: References: Content-Type: multipart/alternative; boundary=Apple-Mail-2--450488204 X-Original-Message-Id: <28293FF5-939F-4E89-86D8-91C6A6D9E8B9@advancedpilot.com> From: Walter Atkinson Subject: Re: [LML] Re: TSIO-550 turbine inlet probes X-Original-Date: Mon, 9 Jul 2007 16:05:41 -0500 X-Original-To: "Lancair Mailing List" X-Mailer: Apple Mail (2.752.3) --Apple-Mail-2--450488204 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=WINDOWS-1252; delsp=yes; format=flowed Dominic: Do this. Place a probe 3" from the exhaust flange, then place another =20= one a foot from the exhaust flange (same cylinder with no other =20 exhaust stream joining in). The one further away will read lower. =20 Why? The gas is expanding and cooling as it flows down the pipe. =20 The TIT reading is higher because the TIT is getting more pulses of =20 exhaust gas per 720 cycle. As a result it has less time to cool =20 between hot pulses. It READS higher. It is not actually hotter. =20 You don't really think the gas gets hotter the further it gets from =20 the exhaust valve, do you? Walter On Jul 9, 2007, at 12:39 PM, Dominic V Crain wrote: =93The TIT GAS is cooler than the exhaust GAS... it's further down the =20= line... it's had time to cool more.=94 HUH? Now- let=92s see. TIT=92s are cooler than EGT=92s? Hmm. So, on that premise, the engine is putting more energy into the gas =20 than it=92s extracting. Which would mean the prop is driving the engine. Nah! I reckon the old theory still works. Burn the gas, measure the TIT, punch the expanding gas through the =20 turbine. Pull out the heat energy to drive the compressor then the =20 prop. Measure the EGT, and PRESTO, the EGT is COOLER that the TIT. Guaranteed. Or Allison=92s rear end doesn=92t point backwards! Regards Dom Crain VH-CZJ --Apple-Mail-2--450488204 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=WINDOWS-1252 Dominic:

Do this. Place a probe 3" = from the exhaust flange, then place another one a foot from the exhaust = flange (same cylinder with no other exhaust stream joining in).=A0 The = one further away will read lower.=A0 Why?=A0 The gas is expanding and = cooling as it flows down the pipe.=A0 The TIT reading is higher because = the TIT is getting more pulses of exhaust gas per 720 cycle.=A0 As a = result it has less time to cool between hot pulses.=A0 It READS higher.=A0= It is not actually hotter.=A0 You don't really think the gas gets = hotter the further it gets from the exhaust valve, do you?

Walter


On Jul 9, = 2007, at 12:39 PM, Dominic V Crain wrote:

=93The TIT GAS is cooler = than the exhaust GAS...=A0 it's further down the line...=A0 it's had = time to cool more.=94

=A0

HUH?

Now- =A0let=92s = see.

TIT=92s are cooler than = EGT=92s?

Hmm.

So, on that premise, the engine is = putting more energy into the gas than it=92s = extracting.

Which would mean the prop is driving = the engine.

Nah!

I reckon the old theory still = works.

Burn the gas, measure the TIT, punch = the expanding gas through the turbine. Pull out the heat energy to drive = the compressor then the prop. Measure the EGT, and PRESTO, the EGT is = COOLER that the TIT.

Guaranteed. Or Allison=92s rear end = doesn=92t point backwards!

Regards

Dom Crain

=A0


= --Apple-Mail-2--450488204--