CHTs - What is acceptable?

[TripFarmer]

What is an acceptable CHT in cruise? How hot can one stay in extended cruise
flight? I've got 6 new ones and want to take care of them.


Thanks in advance.


Trip

[Paul Tomblin]

In a previous article, (TripFarmer) said:
>What is an acceptable CHT in cruise? How hot can one stay in extended cruise
>flight? I've got 6 new ones and want to take care of them.

Our club instructors caution people not to lean the Lance to anything
higher than 1400 degrees.

--
Paul Tomblin > http://xcski.com/blogs/pt/
Every fleeting thought you've ever had in your life, no matter how bizarre,
is someone's lifelong obsession. And he has a website.
-- Skif's Internet Theorem

[Newps]

The big bore Continentals allow you to go to 450. I never let mine get
over 400F which I can only do in the summer anyways. Mine are usually
in the 325-350 range.




TripFarmer wrote:
> What is an acceptable CHT in cruise? How hot can one stay in extended cruise
> flight? I've got 6 new ones and want to take care of them.
>
>
> Thanks in advance.
>
>
> Trip
>

[Jim Weir]

Can I watch while you take the head temperature to 1400°? From a safe distance?

Jim


(Paul Tomblin)
shared these priceless pearls of wisdom:

->In a previous article, (TripFarmer) said:
->>What is an acceptable CHT in cruise? How hot can one stay in extended cruise
->>flight? I've got 6 new ones and want to take care of them.
->
->Our club instructors caution people not to lean the Lance to anything
->higher than 1400 degrees.


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

[zatatime]

On Wed, 18 Aug 2004 22:03:38 +0000 (UTC),
(Paul Tomblin) wrote:

>In a previous article, (TripFarmer) said:
>>What is an acceptable CHT in cruise? How hot can one stay in extended cruise
>>flight? I've got 6 new ones and want to take care of them.
>
>Our club instructors caution people not to lean the Lance to anything
>higher than 1400 degrees.


1400 is EGT not CHT. I keep my CHT around 300 plus or minus.
Lycoming used to say 500, but that's really high the way I see it.

HTH.
z

[Mike Rapoport]

Isn't that above the melting point of aluminium?

Mike
MU-2


"Paul Tomblin" > wrote in message
...
> In a previous article, (TripFarmer) said:
> >What is an acceptable CHT in cruise? How hot can one stay in extended
cruise
> >flight? I've got 6 new ones and want to take care of them.
>
> Our club instructors caution people not to lean the Lance to anything
> higher than 1400 degrees.
>
> --
> Paul Tomblin > http://xcski.com/blogs/pt/
> Every fleeting thought you've ever had in your life, no matter how
bizarre,
> is someone's lifelong obsession. And he has a website.
> -- Skif's Internet Theorem

[john smith]

TripFarmer wrote:
> What is an acceptable CHT in cruise? How hot can one stay in extended cruise
> flight? I've got 6 new ones and want to take care of them.

I asked those questions to each of the Lycoming and Continental reps at
AirVenture a couple of weeks ago.
The answers I got were, it depends on the engine and the airframe in
which they are installed. You need a copy of the engine manual for your
airframe. A range will be given in that reference.
I was asking about Continental TSIO-360FB in a 1979 P28T and a Lycoming
I0-520K1G5 in a 1978 PA32.

[Stan Prevost]

"john smith" > wrote in message
...
> TripFarmer wrote:
> > What is an acceptable CHT in cruise? How hot can one stay in extended
cruise
> > flight? I've got 6 new ones and want to take care of them.
>
> I asked those questions to each of the Lycoming and Continental reps at
> AirVenture a couple of weeks ago.
> The answers I got were, it depends on the engine and the airframe in
> which they are installed. You need a copy of the engine manual for your
> airframe. A range will be given in that reference.
> I was asking about Continental TSIO-360FB in a 1979 P28T and a Lycoming
> I0-520K1G5 in a 1978 PA32.
>

I have seen this but never understood it. Why does the maximum allowable
CHT depend on the airframe?

[Matt Whiting]

Paul Tomblin wrote:

> In a previous article, (TripFarmer) said:
>
>>What is an acceptable CHT in cruise? How hot can one stay in extended cruise
>>flight? I've got 6 new ones and want to take care of them.
>
>
> Our club instructors caution people not to lean the Lance to anything
> higher than 1400 degrees.
>

CHT of 1400? Are you sure this isn't EGT?


Matt

[G.R. Patterson III]

Paul Tomblin wrote:
>
> Our club instructors caution people not to lean the Lance to anything
> higher than 1400 degrees.

Uh ... I think you mean the EGT. CHTs are more in the 200 degree range.

George Patterson
If you want to know God's opinion of money, just look at the people
he gives it to.

[tony roberts]

Nobody here can give you the correct CHT for your aircraft.
The engine manufacturer can, although it's like pulling teeth trying to
get it.

As a general rule, if you hold climbout to a max of 380CHT/1425 EGT and
cruise max at 350 CHT/1380EGT you won't seize or damage anything - that
is not to say that you will be at your most efficient - only that you
won't damage anything.

The most knowledgeable people I have found on this topic are Advance
Pilot Seminars. Walter Atkinson is one of their instructors and he is
often available at Cessna Owner Organization Forums.
I learned more about this subject from him than anyone else.
He teaches ROP leaning on carbs and LOP leaning on Gamis.
He really knows his subject and is the person that I recommend to answer
your question.

HTH

Tony
--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE


In article >,
(TripFarmer) wrote:

> What is an acceptable CHT in cruise? How hot can one stay in extended cruise
> flight? I've got 6 new ones and want to take care of them.
>
>
> Thanks in advance.
>
>
> Trip

[Thomas Borchert]

TripFarmer,

> What is an acceptable CHT in cruise?
>

anything below 400F. Have you read Deakin's columns on engine
management at www.avweb.com?

--
Thomas Borchert (EDDH)

[Ron Natalie]

"Stan Prevost" > wrote in message ...
>\> I have seen this but never understood it. Why does the maximum allowable
> CHT depend on the airframe?
>
>
Not so much the airframe but where the CHT probe is located relative to the actual
head temperatures.

[Javier Henderson]

Yes. The redline on my Skylane is 450F, but I aim for no higher than 400,
and usually manage to keep them in the 370 range.

-jav

"Mike Rapoport" > writes:

> Isn't that above the melting point of aluminium?
>
> Mike
> MU-2
>
>
> "Paul Tomblin" > wrote in message
> ...
> > In a previous article, (TripFarmer) said:
> > >What is an acceptable CHT in cruise? How hot can one stay in extended
> cruise
> > >flight? I've got 6 new ones and want to take care of them.
> >
> > Our club instructors caution people not to lean the Lance to anything
> > higher than 1400 degrees.
> >
> > --
> > Paul Tomblin > http://xcski.com/blogs/pt/
> > Every fleeting thought you've ever had in your life, no matter how
> bizarre,
> > is someone's lifelong obsession. And he has a website.
> > -- Skif's Internet Theorem

[john smith]

Stan Prevost wrote:
> "john smith" > wrote in message
> ...
>
>>TripFarmer wrote:
>>
>>>What is an acceptable CHT in cruise? How hot can one stay in extended
>
> cruise
>
>>>flight? I've got 6 new ones and want to take care of them.
>>
>>I asked those questions to each of the Lycoming and Continental reps at
>>AirVenture a couple of weeks ago.
>>The answers I got were, it depends on the engine and the airframe in
>>which they are installed. You need a copy of the engine manual for your
>>airframe. A range will be given in that reference.
>>I was asking about Continental TSIO-360FB in a 1979 P28T and a Lycoming
>>I0-520K1G5 in a 1978 PA32.
>>
>
>
> I have seen this but never understood it. Why does the maximum allowable
> CHT depend on the airframe?
Baffeling and type of cooling (upflow, downflow, gills, cowl flaps).

[Tom S.]

"TripFarmer" > wrote in message
...
> What is an acceptable CHT in cruise? How hot can one stay in extended
cruise
> flight? I've got 6 new ones and want to take care of them.
>
>
> Thanks in advance.
>

Is yours a turbo? What displacement?

Check out John Deakin's "Engine Series" at
http://www.avweb.com/news/columns/182146-1.html (specifically #'s 8, 18, 43,
63-66).

Never more than 400 degrees and typically at 370-390.

[TripFarmer]

I just don't buy that "airframe" stuff. A cylinder head can only take
so much temperature for so long before it gives in. 400 degrees is
400 degrees no matter what airframe it's in. If I'm wrong please tell
me why.........

I've got about 15 hours on 6 new Superior Millinieums and just put in my
first quart of oil since 2TT. I have a range of temps at cruise from
320 - 380. They dropped a lot after about the first 30 - 60 minutes of
break in and seem to have stabilized since to these numbers. The hot one
will run 400-410 in a full power climb in my PA28 235.


Trip

In article >, says...
>
>TripFarmer wrote:
>> What is an acceptable CHT in cruise? How hot can one stay in extended cruise
>> flight? I've got 6 new ones and want to take care of them.
>
>I asked those questions to each of the Lycoming and Continental reps at
>AirVenture a couple of weeks ago.
>The answers I got were, it depends on the engine and the airframe in
>which they are installed. You need a copy of the engine manual for your
>airframe. A range will be given in that reference.
>I was asking about Continental TSIO-360FB in a 1979 P28T and a Lycoming
>I0-520K1G5 in a 1978 PA32.
>

[TripFarmer]

I just printed them all out to read at home.

Thanks.


Trip

In article >, says...
>
>TripFarmer,
>
>> What is an acceptable CHT in cruise?
>>
>
>anything below 400F. Have you read Deakin's columns on engine
>management at www.avweb.com?
>
>--
>Thomas Borchert (EDDH)
>

[Dave Butler]

TripFarmer wrote:
> I just don't buy that "airframe" stuff. A cylinder head can only take
> so much temperature for so long before it gives in. 400 degrees is
> 400 degrees no matter what airframe it's in. If I'm wrong please tell
> me why.........

I agree the temperature a cylinder can tolerate probably doesn't depend on the
airframe, but the method of measurement might. Where is the CHT probe on the
cylinder? Don't know, but maybe Piper puts the probe in one hole, and Cessna in
another.

[Dan Luke]

"TripFarmer" wrote:
> I've got about 15 hours on 6 new Superior Millinieums and just
> put in my first quart of oil since 2TT. I have a range of temps
> at cruise from 320 - 380. They dropped a lot after about the
> first 30 - 60 minutes of break in and seem to have stabilized
> since to these numbers. The hot one will run 400-410 in a
> full power climb in my PA28 235.

I have the same cylinders in a LYC O-360; they have 500+ hours on them. In
order to keep mine below 380 deg., I have to keep the cowl flaps wide open
in cruise in summer at 75% power. I can lean the engine in climb for better
performance, but it takes careful attention to the mixture to keep the CHTs
under 400.
--
Dan
C-172RG at BFM

[TripFarmer]

I haven't leaned much so far. Only the past 5 hours have I leaned any and
not agressively at that. I will run that one cylinder at 380-390 leaned at 75%. \
65% doesn't help but maybe 10 degrees. This is the hot cylinder. The
others run from 320 - 355. Number 3 is this hot one and number 5 is next but
20-30 degrees less. I feel as long as I keep it under 400 degrees except on
take off it should be ok. I drop back to 23 squared for extended climb and
use a more shallow climb for better cooling.


Trip



In article >, says...
>
>
>"TripFarmer" wrote:
>> I've got about 15 hours on 6 new Superior Millinieums and just
>> put in my first quart of oil since 2TT. I have a range of temps
>> at cruise from 320 - 380. They dropped a lot after about the
>> first 30 - 60 minutes of break in and seem to have stabilized
>> since to these numbers. The hot one will run 400-410 in a
>> full power climb in my PA28 235.
>
>I have the same cylinders in a LYC O-360; they have 500+ hours on them. In
>order to keep mine below 380 deg., I have to keep the cowl flaps wide open
>in cruise in summer at 75% power. I can lean the engine in climb for better
>performance, but it takes careful attention to the mixture to keep the CHTs
>under 400.
>--
>Dan
>C-172RG at BFM
>
>

[Steven Barnes]

"TripFarmer" > wrote in message
...
> What is an acceptable CHT in cruise? How hot can one stay in extended
cruise
> flight? I've got 6 new ones and want to take care of them.
>
>
> Thanks in advance.
>
>
> Trip
>

Our club's Skylane has one CHT gauge with a big 'ol green range & no temps
on it. Any recommendations on how to use this rather "useless" gauge?

[WARREN1157]

> I feel as long as I keep it under 400 degrees except on
>take off it should be ok. I drop

Can a cylinder heat up that much on takeoff? I have never looked.

[john smith]

Steven Barnes wrote:
> Our club's Skylane has one CHT gauge with a big 'ol green range & no temps
> on it. Any recommendations on how to use this rather "useless" gauge?

You don't, it is for reference only.
Lean until the engine starts to run rough, then enrich half- to one-turn
so it runs smooth again.

[Bob Noel]

In article >,
(WARREN1157) wrote:

> > I feel as long as I keep it under 400 degrees except on
> >take off it should be ok. I drop
>
> Can a cylinder heat up that much on takeoff? I have never looked.

yes. My 140 gets pretty close to 500 degrees during climbout
(500 is redline for my engine).

--
Bob Noel
Seen on Kerry's campaign airplane: "the real deal"
oh yeah baby.

[G.R. Patterson III]

Dave Butler wrote:
>
> I agree the temperature a cylinder can tolerate probably doesn't depend on the
> airframe, but the method of measurement might. Where is the CHT probe on the
> cylinder? Don't know, but maybe Piper puts the probe in one hole, and Cessna in
> another.

In a sense, you're probably right. There's a threaded hole in the cylinder head. The
probe goes there, no matter what the airframe. The only way the airframe could make a
difference is if a) they have the probe in only one cylinder and b) the
temperatures on the other cylinders are known to be significantly different.

So, if Piper puts the probe in cylinder #1 for one aircraft and cylinder #4 in
another, the allowable max temperatures are likely to be different for the two.

George Patterson
If you want to know God's opinion of money, just look at the people
he gives it to.

[G.R. Patterson III]

Steven Barnes wrote:
>
> Our club's Skylane has one CHT gauge with a big 'ol green range & no temps
> on it. Any recommendations on how to use this rather "useless" gauge?

That's what my Maule has. I just keep it in the green during climb and descent and
check it every once in a while during cruise.

George Patterson
If you want to know God's opinion of money, just look at the people
he gives it to.

[Tom S.]

"TripFarmer" > wrote in message
...
> I just don't buy that "airframe" stuff. A cylinder head can only take
> so much temperature for so long before it gives in. 400 degrees is
> 400 degrees no matter what airframe it's in. If I'm wrong please tell
> me why.........
>
> I've got about 15 hours on 6 new Superior Millinieums and just put in my
> first quart of oil since 2TT. I have a range of temps at cruise from
> 320 - 380. They dropped a lot after about the first 30 - 60 minutes of
> break in and seem to have stabilized since to these numbers. The hot one
> will run 400-410 in a full power climb in my PA28 235.
>
>

I take it you have a good engine analyzer like the JPI 700?

[WARREN1157]

>> Can a cylinder heat up that much on takeoff? I have never looked.
>
>yes. My 140 gets pretty close to 500 degrees during climbout
>(500 is redline for my engine).

Are takeoff and climbout the same thing?

[WARREN1157]

>> on it. Any recommendations on how to use this rather "useless" gauge?

I had a 182 with the same. I would just use it for a quick reference. Lean it
until it was at the same place as before. For extended cruise I would re-lean
the engine by roughing the engine then smoothing it out.

[Ron Natalie]

"G.R. Patterson III" > wrote in message ...

>. The only way the airframe could make a
> difference is if a) they have the probe in only one cylinder and b) the
> temperatures on the other cylinders are known to be significantly different.
>
And both of the above are the case. Unless you have an engine analyzer
the CHT is only measuring one cylinder. They usually try to put it in the
hottest cylinder (one of the back ones), but that varies based on how the
engine cooling air is designed on the airframe.

The oil temperature temps have an even greater variation.

[James M. Knox]

> In a sense, you're probably right. There's a threaded hole in the
> cylinder head. The probe goes there, no matter what the airframe. The
> only way the airframe could make a difference is if a) they have the
> probe in only one cylinder and b) the temperatures on the other
> cylinders are known to be significantly different.

Actually, it can make a difference even beyond that. The fine folks at
GAMI (as part of their liquid air project) completely instrumented a few
cylinders (dozens of probes each) and went flying. They found > 80
degree differences from one side of some cylinders to the other side.
So even a threaded CHT probe may or may not be telling you the true
temperature of even THAT cylinder.

FWIW, GAMI theorizes that this uneven cooling air around each cylinder
may be a significant cause of the cylinder operating "out of round" and
causing significant scuffing and wear.

[TripFarmer]

I'm in a PA28 235 and I'm seeing 415ish on takeoff on this one cylinder.


Trip

In article >, says...
>
>> I feel as long as I keep it under 400 degrees except on
>>take off it should be ok. I drop
>
>Can a cylinder heat up that much on takeoff? I have never looked.

[TripFarmer]

Wish I did. I have an old analog 6 cylinder anaylzer.


Trip


In article >, says...
>
>
>"TripFarmer" > wrote in message
...
>> I just don't buy that "airframe" stuff. A cylinder head can only take
>> so much temperature for so long before it gives in. 400 degrees is
>> 400 degrees no matter what airframe it's in. If I'm wrong please tell
>> me why.........
>>
>> I've got about 15 hours on 6 new Superior Millinieums and just put in my
>> first quart of oil since 2TT. I have a range of temps at cruise from
>> 320 - 380. They dropped a lot after about the first 30 - 60 minutes of
>> break in and seem to have stabilized since to these numbers. The hot one
>> will run 400-410 in a full power climb in my PA28 235.
>>
>>
>
>I take it you have a good engine analyzer like the JPI 700?
>
>
>
>

[Dan Thomas]

"G.R. Patterson III" > wrote in message >...
> Steven Barnes wrote:
> >
> > Our club's Skylane has one CHT gauge with a big 'ol green range & no temps
> > on it. Any recommendations on how to use this rather "useless" gauge?
>
> That's what my Maule has. I just keep it in the green during climb and descent and
> check it every once in a while during cruise.
>
> George Patterson
> If you want to know God's opinion of money, just look at the people
> he gives it to.


All of the information most people need is available online at

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/MainFrame?OpenFrameSet

These are the Type Certificate Data Sheets (TCDS) for US made
airplanes, engines, propellers and appliances (equipment such as
Carbs, seat belts and so on).
Engine TCDS give CHTs and a lot of other stuff. The statement by
the engine guys that the airframe manufacturer sets CHTs is
misleading.

Dan

[Bob Noel]

In article >,
(WARREN1157) wrote:

> >> Can a cylinder heat up that much on takeoff? I have never looked.
> >
> >yes. My 140 gets pretty close to 500 degrees during climbout
> >(500 is redline for my engine).
>
> Are takeoff and climbout the same thing?

is the distinction important?

--
Bob Noel
Seen on Kerry's campaign airplane: "the real deal"
oh yeah baby.

[Tom S.]

"TripFarmer" > wrote in message
...
> Wish I did. I have an old analog 6 cylinder anaylzer.

If you want to protect your investment it would be HIGHLY recommended to get
a good engine analyzer.

I'm looking at $28K for a IO-550 Milleniunm exchange and I'm going to "baby"
those poppers. The previous owner of my bird had a JPI-700 and he got 1800
hours out of a IO-520 running LOP.

>
> Trip
>
>
> In article >, says...
> >
> >I take it you have a good engine analyzer like the JPI 700?

[Tom S.]

"Bob Noel" > wrote in message
...
> In article >,
> (WARREN1157) wrote:
>
> > >> Can a cylinder heat up that much on takeoff? I have never looked.
> > >
> > >yes. My 140 gets pretty close to 500 degrees during climbout
> > >(500 is redline for my engine).
> >
> > Are takeoff and climbout the same thing?
>
> is the distinction important?
>
Well, yes. Beech recommends 105 for climb out, but better is 120 for better
visibility and MUCH BETTER COOLING. Rate of climb (after obstacle clearance)
is only marginally less (about 1025 fpm vs 1075 in my F33A).

[Bob Noel]

In article >, "Tom S."
> wrote:

> > > >> Can a cylinder heat up that much on takeoff? I have never looked.
> > > >
> > > >yes. My 140 gets pretty close to 500 degrees during climbout
> > > >(500 is redline for my engine).
> > >
> > > Are takeoff and climbout the same thing?
> >
> > is the distinction important?
> >
> Well, yes. Beech recommends 105 for climb out, but better is 120 for
> better
> visibility and MUCH BETTER COOLING. Rate of climb (after obstacle
> clearance)
> is only marginally less (about 1025 fpm vs 1075 in my F33A).

Sure. I do the same type of thing in my 140 - only slower ;-).
WRT to CHT, I have to balance it with the RPM limit from the
160hp STC (yellow arc from 2650 to 2700 - five minute limit).
As a result I often do reduced-power climbs to keep the CHT closer
to 400 degrees and RPM comfortably below 2650.

I probably should look at the baffling, but it would run
pretty hot in climb before the engine overhaul and all new
baffling. Or I should check the CHT calibration again.

--
Bob Noel
Seen on Kerry's campaign airplane: "the real deal"
oh yeah baby.

[Tom Fleischman]

In article >, Steven
Barnes > wrote:
> Our club's Skylane has one CHT gauge with a big 'ol green range & no temps
> on it. Any recommendations on how to use this rather "useless" gauge?
>
>

Keep it in the green.

[Jay Honeck]

> > Wish I did. I have an old analog 6 cylinder anaylzer.
>
> If you want to protect your investment it would be HIGHLY recommended to
get
> a good engine analyzer.

I'll second that motion. It's a tiny percentage of what your engine just
cost, and it provides invaluable data.

Trip and I have the same engine, both in PA28-235s. In my experience, after
observing my new engine with a JPI EDM-700 for several hundred hours, CHTs
of over 400 degrees are WAY out of normal range. I keep mine below 350, and
have no problem doing so.

In cruise they will settle into the 315-320 range. EGTs can range from 1350
to 1500, depending on leaning.

Now if you have only one cylinder out of line, it could be a sensor/probe
problem, or it could be a baffling problem. I sealed all visible holes in
my baffling with high-temp RTV, and saw my CHTs drop slightly, but
noticeably.

Good luck!
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Jay Honeck]

> Our club's Skylane has one CHT gauge with a big 'ol green range & no
temps
> on it. Any recommendations on how to use this rather "useless" gauge?

That's what both our Warrior and Pathfinder had in the panel when we
obtained them. They were almost worse than useless, in my experience.
Using them for reference meant nothing, as leaning "by ear" turned out to be
easier and just as "accurate" (meaning not accurate at all).

As you may have noticed, we've got the one from our Pathfinder on display in
our lobby, along with a whole bunch of other "spare parts."

Heck, it's not even a good doorstop!
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[[email protected]]

Dan Thomas > wrote:
: http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/MainFrame?OpenFrameSet

: These are the Type Certificate Data Sheets (TCDS) for US made
: airplanes, engines, propellers and appliances (equipment such as
: Carbs, seat belts and so on).
: Engine TCDS give CHTs and a lot of other stuff. The statement by
: the engine guys that the airframe manufacturer sets CHTs is
: misleading.

: Dan

While the TCDS might contain the max CHTs and such, many people believe that
they are insane. The metalurgical changes that occur when you run a cylinder up to
the "approved" TCDS limit of 500 degrees are significant. Remember that once a TCDS
is approved, it's basically gospel and can never be changed.... in other words, it's
guaranteed to be wrong forever.

Different airframes' engine limits shouldn't be compared directly, but I know
I would try to take the lowest of all of them as a recommendation. The guys who know
engines say that running over 400 in cruise is bad.

-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering Ph.D. Graduate Student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

[TripFarmer]

Jay,

I'm still running mineral oil. I do expect the CHTs to drop when
I go to Aeroshell. I've got 15TT since TOH now. One quart in last 13 hours.


Trip


In article <TUHVc.59500$TI1.36466@attbi_s52>, says...
>
>> > Wish I did. I have an old analog 6 cylinder anaylzer.
>>
>> If you want to protect your investment it would be HIGHLY recommended to
>get
>> a good engine analyzer.
>
>I'll second that motion. It's a tiny percentage of what your engine just
>cost, and it provides invaluable data.
>
>Trip and I have the same engine, both in PA28-235s. In my experience, after
>observing my new engine with a JPI EDM-700 for several hundred hours, CHTs
>of over 400 degrees are WAY out of normal range. I keep mine below 350, and
>have no problem doing so.
>
>In cruise they will settle into the 315-320 range. EGTs can range from 1350
>to 1500, depending on leaning.
>
>Now if you have only one cylinder out of line, it could be a sensor/probe
>problem, or it could be a baffling problem. I sealed all visible holes in
>my baffling with high-temp RTV, and saw my CHTs drop slightly, but
>noticeably.
>
>Good luck!
>--
>Jay Honeck
>Iowa City, IA
>Pathfinder N56993
>www.AlexisParkInn.com
>"Your Aviation Destination"
>
>