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Date: Mon, 20 Aug 2012 10:43:37 -0500
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Subject: Re: [FlyRotary] Re: EM2 CHT ?
From: Mark Steitle <msteitle@gmail.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
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As a final comment, drilling the rotor housings for thermo-couples
pretty much requires it be done with the engine disassembled.  I would
be very reluctant to try it otherwise.

Mark

On 8/20/12, Ed Anderson <eanderson@carolina.rr.com> wrote:
> Ok, Mark, I get your viewpoint.  I can see where temp rise would be detected
>
> earliest that way and perhaps permit you to throttle back and reduce power
> before perhaps damage occurs.  Be interesting to see what David ends up
> with.
>
> Ed
>
> --------------------------------------------------
> From: "Mark Steitle" <msteitle@gmail.com>
> Sent: Monday, August 20, 2012 10:15 AM
> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> Subject: [FlyRotary] Re: EM2 CHT ?
>
>> Ed,
>>
>> I think the idea is you'll get a more accurate measurement at the
>> combustion surface of each rotor rather than measuring the temp of the
>> coolant that has already blended with other coolant in the system.
>> Its my understanding that the coolant temp will be higher around the
>> plug area than elsewhere, so if you operate near the boiling point of
>> your coolant, you would be able to tell it sooner rather than later.
>> Still, if you know the safe high-temp limit, it seems you would get a
>> better reading off the rotor housing liner than from the coolant.
>>
>> If you drill/tap each rotor housing you can see how hard each rotor is
>> working, similar to EGT's.  CHT can serve as a cross-check to EGT.
>>
>> Also, monitoring cooling system pressure should alert you to an
>> imminent boilover event.  But you already knew that.  ;-)
>>
>>
>> My 2 cents,
>> Mark
>>
>> On 8/20/12, Ed Anderson <eanderson@carolina.rr.com> wrote:
>>> I agree, Mark, that your suggestion would probably get you as close to
>>> an
>>> equivalent CHT as we can get.
>>>
>>> But, I'm still not understanding what that would usefully provide that
>>> is
>>> worth more than your coolant temps.
>>>
>>>  I presume that if for some reason the engine temperature were to
>>> rapidly
>>> increase (perhaps due to detonation or other combustion events) that the
>>>
>>> CHT
>>> reading would provide quicker information on the condition than would
>>> the
>>> coolant temp so perhaps you could take corrective action before damage.
>>> Might be a comfort factor knowing "CHT"  if using forced induction on a
>>> rotary as things can happen pretty fast when at high boost levels.
>>>
>>> Ed
>>>
>>>
>>>
>>>
>>> From: Mark Steitle
>>> Sent: Sunday, August 19, 2012 8:48 PM
>>> To: Rotary motors in aircraft
>>> Subject: [FlyRotary] Re: EM2 CHT ?
>>>
>>>
>>> Seems that this will tell you the coolant temp near the plugs, but not
>>> the
>>> CHT.  If you want to measure the CHT, you'll need to locate a
>>> thermo-couple
>>> down near the steel liner.  You can do this by drilling a small hole
>>> down
>>> into the web adjacent to the leading plug, stopping at the steel liner.
>>> Then insert a thermo-couple down into the hole so that it is touching
>>> the
>>> steel liner.  Now you're reading the temps nearest the combustion
>>> chamber,
>>> closest thing we have to CHT.
>>>
>>>
>>> Mark
>>>
>>>
>>> On Sun, Aug 19, 2012 at 10:02 AM, <hoursaway1@comcast.net> wrote:
>>>
>>>   Sounds like a plan to me Ed, should have time Sun. to do.  David
>>>
>>>
>>> ------------------------------------------------------------------------------
>>>   From: "Ed Anderson" <eanderson@carolina.rr.com>
>>>   To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
>>>   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
>>>   Sent: Friday, August 17, 2012 10:20 PM
>>>   To: Rotary motors in aircraft
>>>   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
>>>
>>>
>>>
>>>
>>>
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>>>
>>>
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>>
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>
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