X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 6.0c1) with ESMTP id 5718386 for flyrotary@lancaironline.net; Sun, 19 Aug 2012 11:45:37 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=2.0 cv=Dp/UCRD+ c=1 sm=0 a=g3L/TDsr+eNLfIieSKfGkw==:17 a=AHkS0RJitIMA:10 a=_xZX3L73zDUA:10 a=05ChyHeVI94A:10 a=UjqRUjD52t0A:10 a=ayC55rCoAAAA:8 a=C_IRinGWAAAA:8 a=Ia-xEzejAAAA:8 a=oCcaPWc0AAAA:8 a=wxJvcQqw1XlxCa3TA8AA:9 a=QEXdDO2ut3YA:10 a=si9q_4b84H0A:10 a=EzXvWhQp4_cA:10 a=8NLzyF9WT6VAnzc1:21 a=j1SdHmA1AF0KFy35:21 a=W8xz4zc4hsMSkDCZOncA:9 a=_W_S_7VecoQA:10 a=frz4AuCg-hUA:10 a=tXsnliwV7b4A:10 a=EnA5vs7L1JRe-rDI:21 a=Ph-QhoHwkPm9DBSd:21 a=g3L/TDsr+eNLfIieSKfGkw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.170.10 Received: from [174.110.170.10] ([174.110.170.10:61416] helo=EdPC) by cdptpa-oedge02.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id EC/E4-13948-DF901305; Sun, 19 Aug 2012 15:45:01 +0000 Message-ID: <02325D7E3343420D9704B2DD35D4373F@EdPC> From: "Ed Anderson" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: EM2 CHT ? Date: Sun, 19 Aug 2012 11:45:01 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0015_01CD7E00.11176CA0" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 This is a multi-part message in MIME format. ------=_NextPart_000_0015_01CD7E00.11176CA0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable David, I suspect there will undoubtedly be a bit of lag before the heat = of the coolant/oil inside the engine transferred to the outside of the = aluminum housings - so I suspect the CHT temp would lag (just don't know = how much). But, one would assume after a bit of engine operation they = would stabilize at some temperature as they reach steady state = condition. However, I have doubts about the usefulness of a CHT for the rotary = engine (or any liquid cooled engine). Here is my rational. 1. Air cooled aircraft engines transfer the heat directly from the = combustion chamber to the cylinder walls and fins of the cylinder. So = the CHT gives you a pretty direct indication of how things are going. = One the other hand, the rotary (and any liquid cooled engine) has the = coolant inside the engine transferring heat away. So, In contrast to = the air cooled engine, relatively little heat is being transferred to = the outside walls in the liquid cooled engine. Didn't say None, just a = small amount compared to what you are getting rid of through your = coolant. 2. So, I am not certain what a CHT reading will tell you that the = coolant temp won't tell you sooner. In the air cooled aircraft engine, = they of course do not have this option. 3. The CHT for the rotary could perhaps provide some useful information = if it was mounted close to the sparkplug location as this is reportedly = the hottest part of the chamber. But, on the other hand, its sort of = is- what- it -is and I don't how you would affect temperature in that = area much except by keeping your coolant flow cooler. So once again, it = sort of boils (no pun intended) down to your coolant temps. On the other hand, I certainly don't see any possible harm it would do = to instrument it with CHTs. Be interested in the results. So keep us informed, David Best Regards Ed From: hoursaway1@comcast.net=20 Sent: Sunday, August 19, 2012 11:02 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: EM2 CHT ? Sounds like a plan to me Ed, should have time Sun. to do. David -------------------------------------------------------------------------= ------- From: "Ed Anderson" To: "Rotary motors in aircraft" Sent: Saturday, August 18, 2012 6:54:35 AM Subject: [FlyRotary] Re: EM2 CHT ? I think I would run the engine at operational rpms (>5000) and watch the = coolant/oil temperatures - when they got to my maximum limit, I would = check the CHT reading and perhaps add 50 degrees for the limit (to start = with). If I got a lot of false alarms at that margin I would try = another 50 deg. Just a WAG. Ed From: hoursaway1@comcast.net=20 Sent: Friday, August 17, 2012 10:20 PM To: Rotary motors in aircraft=20 Subject: [FlyRotary] EM2 CHT ? What are we using for high temp numbers from the CHT sensors on the 13B = rotary, I have the under the spark plug style sensors bolted to each = rotor housing in some factory threaded holes just above the spark plugs, = not really the hottest spot but the holes were already in place so I = KISSed it & moved on, now I need to set my high temp warning limit & do = not know what to use. Possibly do an eng. run with upper cowl off & = check bolt/sensor temp with a lazer temp gun at about 4000 RPM & go = another 50 deg. higher? Ideas? David R. Cook RV6A Rotary=20 No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2197 / Virus Database: 2437/5206 - Release Date: = 08/17/12 No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2197 / Virus Database: 2437/5209 - Release Date: = 08/19/12 ------=_NextPart_000_0015_01CD7E00.11176CA0 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
David, I suspect  there will undoubtedly be = a bit of=20 lag before the heat of the coolant/oil inside the engine transferred to = the=20 outside of the aluminum housings - so I suspect the CHT temp would lag = (just=20 don't know how much).   But, one would assume after a bit of = engine=20 operation they would stabilize at some temperature as they reach steady = state=20 condition.
 
However, I have doubts about  the = usefulness of a CHT for the rotary engine (or any liquid cooled = engine). =20 Here is my rational.
 
1.  Air cooled aircraft engines transfer = the heat=20 directly from the combustion chamber to the cylinder walls and fins of = the=20 cylinder.  So the CHT gives you a pretty direct indication of how = things=20 are going.  One the other hand, the rotary (and any liquid cooled = engine)=20 has the coolant inside the engine transferring heat away. So, =  In=20 contrast to the air cooled engine, relatively little heat is being = transferred=20 to the outside walls in the liquid cooled engine.  Didn't say None, = just a=20 small amount compared to what you are getting rid of through your=20 coolant.
 
2. So,  I am not certain what a CHT = reading will=20 tell you that the coolant temp won't tell you sooner.  In the air = cooled=20 aircraft engine, they of course do not have this =  option.
 
3.  The CHT for the rotary could perhaps = provide some=20 useful information if it was mounted close to the sparkplug location as = this is=20 reportedly the hottest part of the chamber.  But, on the other = hand, its=20 sort of is- what- it -is and I don't how you would affect temperature in = that=20 area much except by keeping your coolant flow cooler.  So once = again, it=20 sort of boils (no pun intended) down to your coolant temps.
 
On the other hand, I certainly don't see any = possible harm=20 it would do to instrument it with CHTs.
 
Be interested in the results.
 
So keep us informed, David
 
Best Regards
 
Ed

Sent: Sunday, August 19, 2012 11:02 AM
Subject: [FlyRotary] Re: EM2 CHT ?

Sounds like a=20 plan to me Ed, should have time Sun. to do.  David

From: "Ed Anderson" <eanderson@carolina.rr.com&g= t;
To:=20 "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent:=20 Saturday, August 18, 2012 6:54:35 AM
Subject: [FlyRotary] = Re: EM2=20  CHT ?

I think I would run the engine at operational = rpms=20 (>5000) and watch the coolant/oil temperatures - when they got to my = maximum=20 limit, I would check the CHT reading and perhaps add 50 degrees for the = limit=20 (to start with).  If I got a lot of false alarms at that margin I = would try=20 another 50 deg.  Just a WAG.
 
Ed

From: hoursaway1@comcast.net=20
Sent: Friday, August 17, 2012 10:20 PM
To: Rotary = motors in=20 aircraft
Subject: [FlyRotary] EM2 CHT ?

What are we using for high temp numbers from the CHT sensors on the = 13B=20 rotary, I have the under the spark plug style sensors bolted to each = rotor=20 housing in some factory threaded holes just above the spark plugs, not = really=20 the hottest spot but the holes were already in place so I KISSed it = & moved=20 on, now I need to set my high temp warning limit & do not know what = to=20 use.  Possibly do an eng. run with upper cowl off & check=20 bolt/sensor temp with a lazer temp gun at about 4000 RPM  & go = another=20 50 deg. higher?  Ideas?  David R. Cook  RV6A = Rotary 

 

 

No virus found in this message.
Checked by AVG - www.avg.com
Version: = 2012.0.2197=20 / Virus Database: 2437/5206 - Release Date: 08/17/12

No virus found in this=20 message.
Checked by AVG - www.avg.com
Version: 2012.0.2197 / = Virus=20 Database: 2437/5209 - Release Date: 08/19/12

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