X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-gg0-f180.google.com ([209.85.161.180] verified) by logan.com (CommuniGate Pro SMTP 6.0c3) with ESMTPS id 5931399 for flyrotary@lancaironline.net; Mon, 10 Dec 2012 09:49:59 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.161.180; envelope-from=rwstracy@gmail.com Received: by mail-gg0-f180.google.com with SMTP id c4so485756ggn.25 for ; Mon, 10 Dec 2012 06:49:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:references:from:content-type:x-mailer:in-reply-to :message-id:date:to:content-transfer-encoding:mime-version; bh=oZGRZMyRP/nKrdnLKzDlqE3K33VOGnZ8Ir7nWp81TDQ=; b=iQ0sKqKFuMvMAPFS38YlIH51Q4AyMwTsixMjFGJH1UmBcHVDBeGjbRc3BrYVgQqi1C 6pzlKBiYIPd2vy7JG4cH9l3WHT1X/LHj53buzBh2x99RhpWateEyINULIpBTLvNR5hVP mFWt4rGasISHDCN08w9teCf2ex07Xbg5+HVx1EYIvp2bGCIkxoBVumLCJUoeV94/OiCT oP81Q5Tcvf+izzROkVqtjoIQ04scy420AXzcy5aFv/0x4re6YpVA3Kg7P4gUehO3Bz/t WjxeEa9d3Pl6Y5SCzs7K1zYNuJ0ipbfskNPOnxhby9MoxKqwV2+z+StokUhwrW4KGW+K zO9g== Received: by 10.236.92.172 with SMTP id j32mr21493583yhf.37.1355150965116; Mon, 10 Dec 2012 06:49:25 -0800 (PST) Return-Path: Received: from [192.168.1.5] (15.sub-70-193-194.myvzw.com. [70.193.194.15]) by mx.google.com with ESMTPS id s19sm24471604anl.22.2012.12.10.06.49.21 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 10 Dec 2012 06:49:24 -0800 (PST) Subject: Re: [FlyRotary] What is the value of CHT? References: From: Tracy Content-Type: multipart/alternative; boundary=Apple-Mail-977B2539-45FE-424E-8EF1-5CDD3A924948 X-Mailer: iPad Mail (10A523) In-Reply-To: Message-Id: <8F5CDDF6-B36C-4CBF-AF78-E5F5F41918F5@gmail.com> Date: Mon, 10 Dec 2012 09:49:20 -0500 To: Rotary motors in aircraft Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) --Apple-Mail-977B2539-45FE-424E-8EF1-5CDD3A924948 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable You are generally correct about CHTs but having a bunch of thermocouple chan= nels on your monitor can be useful in an alternative engine installation. B= eing able to clamp a piece of thermocouple wire to any part of the installat= ion (or just dangle it in the airstream behind a heat exchanger) can give yo= u a lot of clues about how your cooling system is working. I use them to m= easure things like gear box temperature, under cowl temps, coolant and oil t= emp on the inlet or outlet that is not normally measured to see differential= s and the aforementioned air temps just behind the heat exchangers. I also u= se one clamped where the knock sensor usually goes because that will probab= ly be the first indication of coolant loss. The EM3 has 8 CHT & 8 EGT inp= uts and any of these can be used for these purposes. You can also assign 2= of them to the main coolant & oil temperature readouts if a thermocouple is= easier to mount in your installation. A standard 18mm CHT thermocouple fi= ts perfectly under the AN adapter on the oil inlet to the engine so I used t= hat to monitor oil temp. =20 Temp sensors can be made from thermocouple wire by just twisting the ends to= gether. If you have gas welding available, melt the very end of the twisted= wires together for stability or crimp a butt splice over them with the insu= lation removed. Tracy Sent from my iPad On Dec 10, 2012, at 9:25 AM, "Gordon Alling" wrote: > I=E2=80=99m thinking about engine monitors and what parameters I need to w= atch. I=E2=80=99m wondering about the value of cylinder head temperatures i= n a water-cooled engine. For an air-cooled engine, CHT is valuable as a mea= sure of engine overheat. For the water-cooled rotary, the coolant temp supp= lies that info. So, what is the additional benefit of monitoring CHTs (in a= ddition to coolant temp). > =20 > What am I missing? > =20 > Gordon C. Alling, Jr., PE > President > acumen Engineering/Analysis, Inc. > =20 > 540-786-2200 > www.acumen-ea.com > =20 --Apple-Mail-977B2539-45FE-424E-8EF1-5CDD3A924948 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
You are generally correct about CHTs b= ut having a bunch of thermocouple channels on your monitor can be useful in a= n alternative engine installation.   Being able to clamp a piece of the= rmocouple wire to any part of the installation (or just dangle it in the air= stream behind a heat exchanger) can give you a lot of clues about how your c= ooling system is working.   I use them to measure things like gear box t= emperature, under cowl temps, coolant and oil temp on the inlet or outlet th= at is not normally measured to see differentials and the aforementioned air t= emps just behind the heat exchangers.  I also use one  clamped whe= re the knock sensor usually goes because that will probably be the first ind= ication of coolant loss.    The EM3 has 8 CHT & 8 EGT inputs a= nd any of these can be used for these purposes.   You can also assign 2= of them to the main coolant & oil temperature readouts if a thermocoupl= e is easier to mount in your installation.   A standard 18mm CHT thermo= couple fits perfectly under the AN adapter on the oil inlet to the engine so= I used that to monitor oil temp.   

Temp= sensors can be made from thermocouple wire by just twisting the ends togeth= er.  If you have gas welding available, melt the very end of the twiste= d wires together for stability or crimp a butt splice over them with the ins= ulation removed.

Tracy

Sent from my iPad

On Dec 10, 2012, at 9:25 AM, "Gordon Alling" <gordon@acumen-ea.com> wrote:

=

I=E2=80=99m thin= king about engine monitors and what parameters I need to watch.  I=E2=80=99m wondering about the value of cy= linder head temperatures in a water-cooled engine.  For an air-cooled engine, CHT is valuable as a measure o= f engine overheat.  For the wat= er-cooled rotary, the coolant temp supplies that info.  So, what is the additional benefit of monitoring CH= Ts (in addition to coolant temp).

 

= What am I missing?

 

Gordon C. Alling, Jr., PE

President

ac= umen Engineerin= g/Analysis, Inc.

=  

540-786-2200

www.acumen-ea.com

=  

= --Apple-Mail-977B2539-45FE-424E-8EF1-5CDD3A924948--