CHT Gauge Limit Settings

How to keep the Cessna 170 flying and airworthy.

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edbooth
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Re: CHT Gauge Limit Settings

Post by edbooth »

Wow, I think everyone is getting Covid-19itis !
Ed Booth, 170-B and RV-7 Driver
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c170b53
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Re: CHT Gauge Limit Settings

Post by c170b53 »

Nice out Ed...
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
Metal Master
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Re: CHT Gauge Limit Settings

Post by Metal Master »

On the only type certificate E-235 listed for the O-300, C-145-2 series engines note 1. States:
NOTE 1. Maximum permissible cylinder head, barrel and oil inlet temperatures, 525°F, 290°F, and 225°F,
respectively.
An all I can say is wow? It is interesting that there is no coverage for the GO-300 that I could find. Similar to close temperatures are listed for the 125 series of engine but they are slightly different.
Regards,
Jim
A&P, IA, New owner C170A N1208D, Have rebuilt some 50 aircraft. So many airplanes, So little time!
Metal Master
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Re: CHT Gauge Limit Settings

Post by Metal Master »

I found the The GO-300 Type certificate E-298
NOTE 1. Maximum permissible temperatures
Cylinder Head Cylinder Barrel Oil Inlet
525F----------290F-----------225F
(Spark plug gasket-downdraft cooling)
A&P, IA, New owner C170A N1208D, Have rebuilt some 50 aircraft. So many airplanes, So little time!
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GAHorn
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Re: CHT Gauge Limit Settings

Post by GAHorn »

I’m glad he has a bookseller on our forums.
I didn’t make this personal, Richard. You did.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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n2582d
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Re: CHT Gauge Limit Settings

Post by n2582d »

I found the attached Service Information Bulletin under Continental's Historical Service Document's section.
Gary
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GAHorn
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Re: CHT Gauge Limit Settings

Post by GAHorn »

n2582d wrote:I found the attached Service Information Bulletin under Continental's Historical Service Document's section.
Effect of Over Temperature Operation and High Piston Blow-By on Cylinder Safety.pdf
That is Airmotive Engineering Corp’s version of Mike Busch’s article (almost a copy)... they are the sister company of ECI who challenged the FAA AD-note on the affected ECI cylinders.... they are not a disinterested party, and in their own testimony claim their CHT limit is 460-F.

They DID NOT claim (in their argument with FAA) that “blow by” had anything to do with high CHTs.

They tried to blame it on Pilot-Error, detonation and pre-ignition.... their statement was “ In some cases, the failures were caused by improper leaning and powerplant management by the pilot; in other cases, they were caused by abnormal combustion events such as heavy detonation and pre-ignition that can cause thermal runaway and rapidly increase CHT to temperatures of 650°F or more.”

http://www.aero-news.net/index.cfm?do=m ... 2a7885b096
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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TFA170
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Re: CHT Gauge Limit Settings

Post by TFA170 »

:lol: :lol:
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n2582d
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Re: CHT Gauge Limit Settings

Post by n2582d »

GAHorn wrote:They DID NOT claim (in their argument with FAA) that “blow by” had anything to do with high CHTs.
George, that's sure not how I read the last sentence in the Aero-News clip you linked:
... In addition, the replacement cylinders are then broken in “in the field” rather than on the test stand in an engine shop, which often leads to improper break-in and excessive blow-by that can overheat and compromise the integrity of the head-to-barrel junction of the replaced cylinder.
Gary
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GAHorn
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Re: CHT Gauge Limit Settings

Post by GAHorn »

Gary, re-read the entire document. My statement was in reference to that portion “in their argument with FAA” .....in which no mention was made of blow-by. Their cause of head separation was exceeding CHT limits.

The only mention of blow-by was completely in that closing-sentence, ...and UN-supported. This is like a coroner claiming death was caused by “blunt force trauma” .... while conveniently not mentioning the deceased had leapt from a tall bldg. :lol:

On TOP of THAT.... if one considers that entire last paragraph.... they are actually claiming that cylinder replacement IN THE FIELD is a BAD thing... ECI cylinders can only be properly broken-in IN A TEST CELL!

Yeah...right... like that’s going to “fly” with the aviation public. Ya’ think that’s gonna sell a lot of ECI cylinders?
They can’t have it both ways.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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TFA170
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Re: CHT Gauge Limit Settings

Post by TFA170 »

:lol: :lol:
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c170b53
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Re: CHT Gauge Limit Settings

Post by c170b53 »

George wrote
I believe CYCLES have a lot to do with it however. You can only bend a paperclip so many times before it fails. And certainly exceeding OEM CHT limits is bad. I
1) Pilot economics affected by the environmental movement, many cylinder repair / reman shops have closed.
2) Why is it I find myself doing just that when buried in work paperwork, (seeking success I guess ) inner voice).
Lots of info here, just my opinion but many cylinders are successfully replaced in the field. As for break in’s its nice to know In present aircraft system design, depressed rudder pedals are not part of the engine start logic.
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
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