C182S - CHT's and EGT's

[john smith]

Any flying a C182S with all six cylinders being monitored, what are you
seeing for CHT's EGT's(corresponding power settings and fuel flows)?
At 65% power 23" MP and 2300 RPM I am seeing 1400 deg F CHT's and 410
deg F CHT's with fuel flows lean of peak about 12-13 gph.

[Jim Weir]

Can't speak to the S model, only the A model. Normal EGT is 1475 and CHT runs
about a needle below 350.

Jim


john smith >
shared these priceless pearls of wisdom:

->Any flying a C182S with all six cylinders being monitored, what are you
->seeing for CHT's EGT's(corresponding power settings and fuel flows)?
->At 65% power 23" MP and 2300 RPM I am seeing 1400 deg F CHT's and 410
->deg F CHT's with fuel flows lean of peak about 12-13 gph.

Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com

[gwengler]

john smith > wrote in message >...
> Any flying a C182S with all six cylinders being monitored, what are you
> seeing for CHT's EGT's(corresponding power settings and fuel flows)?
> At 65% power 23" MP and 2300 RPM I am seeing 1400 deg F CHT's and 410
> deg F CHT's with fuel flows lean of peak about 12-13 gph.

Whoa! Lycoming engines are recommended to be run at CHTs of 400 deg F
or below. And Lycoming does not recommend running the engine lean of
peak. To quote from one of their publications:

"The fact is that the technique of operating lean of peak and power
recovery was discontinued due to the resulting increase in service
issues. Burned pistons, valves, ruined rod and main bearings were
traced to the inability of pilots to utilize this technique with the
instrumentation and distractions found in the typical general aviation
aircraft. If Lycoming felt that this was indeed an efficient and
reliable method of operation, you can be sure that it would be in our
recommended procedures."

Gerd
ATPL, T182T

[Dan Luke]

"gwengler" wrote:
> "The fact is that the technique of operating lean of peak and power
> recovery was discontinued due to the resulting increase in service
> issues. Burned pistons, valves, ruined rod and main bearings were
> traced to the inability of pilots to utilize this technique with the
> instrumentation and distractions found in the typical general aviation
> aircraft. If Lycoming felt that this was indeed an efficient and
> reliable method of operation, you can be sure that it would be in our
> recommended procedures."

Translation: "There's nothing really wrong with it, but Lycoming considers
most pilots too ignorant and careless to do it properly."

(Not that I necessarily disagree with this.)

Dan
C172RG at BFM

[Newps]

john smith wrote:
> Any flying a C182S with all six cylinders being monitored, what are you
> seeing for CHT's EGT's(corresponding power settings and fuel flows)?
> At 65% power 23" MP and 2300 RPM I am seeing 1400 deg F CHT's and 410
> deg F CHT's with fuel flows lean of peak about 12-13 gph.

That's way too hot on your CHT's. On my 67 I have a hard time getting
over about 325 on the CHT.

[Corky Scott]

On Thu, 16 Sep 2004 14:47:43 GMT, john smith > wrote:

>Any flying a C182S with all six cylinders being monitored, what are you
>seeing for CHT's EGT's(corresponding power settings and fuel flows)?
>At 65% power 23" MP and 2300 RPM I am seeing 1400 deg F CHT's and 410
>deg F CHT's with fuel flows lean of peak about 12-13 gph.

Not positive about this but it does not sound like you actually got to
the lean of peak setting. If you had, the cylinderhead temps would
have been MUCH lower. The old Pratt and Whitney charts indicate that
aluminum begins to loose strength at 400 degrees.

Corky Scott

[john smith]

If I go a few degrees lower, the engine sputters.

Corky Scott wrote:
> On Thu, 16 Sep 2004 14:47:43 GMT, john smith > wrote:
>
>
>>Any flying a C182S with all six cylinders being monitored, what are you
>>seeing for CHT's EGT's(corresponding power settings and fuel flows)?
>>At 65% power 23" MP and 2300 RPM I am seeing 1400 deg F CHT's and 410
>>deg F CHT's with fuel flows lean of peak about 12-13 gph.
>
>
> Not positive about this but it does not sound like you actually got to
> the lean of peak setting. If you had, the cylinderhead temps would
> have been MUCH lower. The old Pratt and Whitney charts indicate that
> aluminum begins to loose strength at 400 degrees.
>
> Corky Scott

[Morgans]

"john smith" > wrote in message
...
> If I go a few degrees lower, the engine sputters.
>
Do you have GAMI injectors? If not, "Thou shalt not run LOP!"

Follow engine manufacture's instructions, if you can't get down to their Max
CHT's.
--
Jim in NC


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.762 / Virus Database: 510 - Release Date: 9/13/2004

[Corky Scott]

On Thu, 16 Sep 2004 22:16:31 -0400, "Morgans"
> wrote:

>"john smith" > wrote in message
...
>> If I go a few degrees lower, the engine sputters.
>>
>Do you have GAMI injectors? If not, "Thou shalt not run LOP!"
>
>Follow engine manufacture's instructions, if you can't get down to their Max
>CHT's.

I strongly agree. If you cannot reach lean of peak without having the
engine run rough, then don't.

Because of your particular fuel/air distribution situation, it appears
you will have to run rich of peak at all times in order to achieve
smooth running. I suggest you lean to peak and then richen for the
POH suggested temps and just accept the higher fuel burn than running
lean of peak offers. It's not good to be running CHT's higher than
400F. It's not great to be running even that high, you should try to
keep them under 400F.

This is all spelled out in minute detail in John Deakin's AVweb column
"Mixture Magic". See below.

http://www.avweb.com/news/columns/182084-1.html

Corky Scott

[john smith]

Yes. CHT's are within 10 deg F over the six cylinders, with #4 being the
hottest. EGT's, I don't remember, but they also have a small spread.

Morgans wrote:
> "john smith" > wrote in message
> ...
>
>>If I go a few degrees lower, the engine sputters.
>>
>
> Do you have GAMI injectors? If not, "Thou shalt not run LOP!"
>
> Follow engine manufacture's instructions, if you can't get down to their Max
> CHT's.