X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from lrcmmta08-srv.windstream.net ([166.102.165.80] verified) by logan.com (CommuniGate Pro SMTP 5.3.1) with ESMTP id 4084482 for flyrotary@lancaironline.net; Fri, 15 Jan 2010 20:35:03 -0500 Received-SPF: pass receiver=logan.com; client-ip=166.102.165.80; envelope-from=montyr2157@windstream.net Return-Path: X-WS-COS: WSOB804 X-Cloudmark-Category: Undefined:Undefined X-Cloudmark-Analysis: v=1.1 cv=t7ob+fJgFDLbPRYyWkvvy2UUyOFmdue9w2+488DP/Ps= c=1 sm=0 a=Ia-xEzejAAAA:8 a=IpslU4ztAAAA:8 a=oCcaPWc0AAAA:8 a=Ch0bZqDWtnx_eabtGQQA:9 a=31EQMpF5hlX0-fkZEf8A:7 a=gb1209rZeUHjLZaAeWNuy4dlILMA:4 a=cr0eg9oN50EA:10 a=EzXvWhQp4_cA:10 a=hKMwDgyXfjDZcs-E:21 a=GKkf6IpqWecCuBjn:21 a=SSmOFEACAAAA:8 a=pedpZTtsAAAA:8 a=hG1ilDDYAAAA:8 a=4QdToxKl745aC7_aSpoA:9 a=yzLllnJvLCdQ6p6YR8gA:7 a=TkNffcmGA-jxFh942imR6gtEPG0A:4 a=d-1ze5jHbJEA:10 a=eJojReuL3h0A:10 a=cORMJBpgUsglKQVuzX8koA==:117 X-Cloudmark-Score: 0 Authentication-Results: lrcmmta08 smtp.user=montyr2157; auth=pass (LOGIN) Received: from [98.20.249.108] ([98.20.249.108:60981] helo=newbox) by lrcmmta08 (envelope-from ) (ecelerity 2.2.2.45 r()) with ESMTPA id ED/25-22370-3A7115B4; Fri, 15 Jan 2010 19:34:28 -0600 Message-ID: From: "MONTY ROBERTS" To: "Rotary motors in aircraft" References: Subject: Re: Mechanical gauges Date: Fri, 15 Jan 2010 19:34:19 -0600 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0085_01CA9619.BB1D0330" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_0085_01CA9619.BB1D0330 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable All the mechanical temp gauges I have ever seen worked by measuring the = change in pressure of a fluid that is in a bulb of some type. Altitude = has nothing to do with it since it is a closed system. They are actually = a pressure gauge with the change in pressure correlated to temperature = of the fluid in the bulb VS a spring. It works just like a mercury = thermometer.=20 I don't like mechanical pressure gauges for engine fluids because most = of them use crappy nylon line with brass compression fittings. I have = had these fail and spray oil all over hot headers. Not good. So if you = use one make sure to replace the cheap nylon line with AN hardware. = Mechanical gauges introduce another mission critical point of failure. I = have also had the gauges start leaking oil. These were high quality = automotive racing type gauges.=20 The nice thing about electrical sending units is when they fail the = sender is still a pipe plug. It's also a lot easier to run signal wire, = than plumbing, or thread the big bulb of a temp sender through the = firewall. In addition the wire is still useable without ripping it out = even if you go with a new gauge and sender. This is not true with a = capillary and bulb system. You have to rip it all out and thread the new = one in. Plus the capillary tube is usually way too long and you can't = cut it. Monty ----- Original Message -----=20 From: Bill Bradburry=20 To: Rotary motors in aircraft=20 Sent: Friday, January 15, 2010 7:09 PM Subject: [FlyRotary] Re: Mechanical gauges Perhaps nothing. I don't have a clue as to how they would work. Looks = like it would be either pressure. or fluid running in a circuit. If it = is pressure, how would it adjust to changes in altitude? If fluid, then = how could you calibrate for the loss of temp between the engine and = gage? I like the electrical ones.at least I have a vague notion of how = it works. :>) =20 Bill B =20 -------------------------------------------------------------------------= ----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of ben haas Sent: Friday, January 15, 2010 3:28 PM To: Rotary motors in aircraft Subject: [FlyRotary] Mechanical gauges What is wrong with a mechanical temp gauge that uses a capillary tube = for a sender? Ben Haas www.haaspowerair.com -------------------------------------------------------------------------= ----- Hotmail: Trusted email with Microsoft's powerful SPAM protection. Sign = up now.=20 -------------------------------------------------------------------------= ----- No virus found in this incoming message. Checked by AVG - www.avg.com=20 Version: 8.5.432 / Virus Database: 270.14.142/2623 - Release Date: = 01/15/10 07:35:00 ------=_NextPart_000_0085_01CA9619.BB1D0330 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
All the mechanical temp gauges I have = ever seen=20 worked by measuring the change in pressure of a fluid that is in a bulb = of some=20 type. Altitude has nothing to do with it since it is a closed system. = They are=20 actually a pressure gauge with the change in pressure correlated to = temperature=20 of the fluid in the bulb VS a spring. It works just like a mercury = thermometer.=20
 
I don't like mechanical pressure gauges = for engine=20 fluids because most of them use crappy nylon line with brass compression = fittings. I have had these fail and spray oil all over hot headers. Not = good. So=20 if you use one make sure to replace the cheap nylon line with AN=20 hardware. Mechanical gauges introduce another mission critical = point=20 of failure. I have also had the gauges start leaking oil. These were = high=20 quality automotive racing type gauges.
 
The nice thing about electrical sending = units is=20 when they fail the sender is still a pipe plug. It's also a lot easier = to run=20 signal wire, than plumbing, or thread the big bulb of a temp sender = through the=20 firewall. In addition the wire is still useable without ripping it out = even if=20 you go with a new gauge and sender. This is not true with a capillary = and bulb=20 system. You have to rip it all out and thread the new one in. Plus the = capillary=20 tube is usually way too long and you can't cut it.
 
Monty
----- Original Message -----
From:=20 Bill=20 Bradburry
Sent: Friday, January 15, 2010 = 7:09=20 PM
Subject: [FlyRotary] Re: = Mechanical=20 gauges

Perhaps nothing=85 I = don=92t have a=20 clue as to how they would work.  Looks like it would be either = pressure=85=20 or fluid running in a circuit.  If it is pressure, how would it = adjust to=20 changes in altitude?  If fluid, then how could you calibrate for = the loss=20 of temp between the engine and gage?  I like the electrical = ones=85at least=20 I have a vague notion of how it works=85 =20 :>)

 

Bill=20 B

 

From:=20 Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] On=20 Behalf Of ben haas
Sent: Friday, January 15, 2010 = 3:28=20 PM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Mechanical = gauges

What is wrong with a = mechanical=20 temp gauge that uses a capillary tube for a = sender?

Ben=20 Haas
www.haaspowerair.com


Hotmail: Trusted email = with=20 Microsoft=92s powerful SPAM protection. Sign up=20 now.


No virus found in this incoming message.
Checked by AVG = -=20 www.avg.com
Version: 8.5.432 / Virus Database: 270.14.142/2623 - = Release=20 Date: 01/15/10 07:35:00
------=_NextPart_000_0085_01CA9619.BB1D0330--