High EGT on climb-out

[Janat83]

 

Hello Mooniacs

Today I was climbing from sea level and OAT of 65°F when I noticed that my EGT is higher than usual, I was climbing at 2700rpm and WOT, my engine monitor was showing 1420 on EGT#1, all CHT was under 400, I couldn't lean the mixture above 4000 because when I did that the EGT went to 1520°F and if I keep the mixture rich the engine will not be as smooth, I climbed to 8500 and EGT was at 1470°F and peak was 1570°F, I wonder if this is normal, all CHT was under 400 and on cruise it was really low, like 320° and OAT was 32°F

Thanks in advance

 

Sent from my SM-G975U using Tapatalk

 

 

 

Edited June 27, 2019 by Janat83

[Cyril Gibb]

EGT ABSOLUTE temperature is almost irrelevant.  It’s highly dependent on where the probes were installed on the exhaust header. 

CHT is what matters.  If you’re under 400, you’re fine.

[Hank]

EGT numbers only matter relative to the peak value, the actual number doesn't mean much (although it's easy to remember when leaning). Keep your CHT and Oil Temp happy innthe climb is the best you can do. You don't mention which model you have, but this is generally done by keeping the mixture forward as you do. Should be 150-200°F richer than peak, but I don't tiuch mine until I'm plenty high.

[carusoam]

Proving again the value of raw EGT data...

The value of MS comes from discussions amongst people that have a hint of what engine we are discussing...

Janat, time to update the info in your avatar area...

I’m not sure what an SM-G975U is, But if you are using a tiny screen, you probably aren’t seeing what everybody else has available to them...

As for hot CHTs.... they are one part heating, and one part cooling...

high EGTs come with higher OATs... and mixture...

high CHTs come with higher OATs... and hot EGTs... and crummy cooling...

Crummy cooling comes from ancient dog houses, or crummy climb operations...

How well is your dog house maintained? Do you have a dog house?

What speed were you climbing out at, 120mias?

Request for more basic data... remind us of...

• what do you have?
• how are you using it?
• first time flying this machine in warmer weather?

 

You May have written this all in another thread... but there isn’t a way for me to be able to remember all the MSer’s planes...

I can barely remember my own plane...   

Best regards,

-a-

 

[DXB]

15 hours ago, Janat83 said:

 

Hello Mooniacs

Today I was climbing from sea level and OAT of 65°F when I noticed that my EGT is higher than usual, I was climbing at 2700rpm and WOT, my engine monitor was showing 1420 on EGT#1, all CHT was under 400, I couldn't lean the mixture above 4000 because when I did that the EGT went to 1520°F and if I keep the mixture rich the engine will not be as smooth, I climbed to 8500 and EGT was at 1470°F and peak was 1570°F, I wonder if this is normal, all CHT was under 400 and on cruise it was really low, like 320° and OAT was 32°F

Thanks in advance

I don't fully understand the situation or your description of exactly what happens in cruise.  Title indicates a CHT issue, but statements above describe  a much higher EGT than usual on #1 with no CHT issue at all. Can you clarify?  Also are you SURE #1 EGT is suddenly much higher than usual in comparison to baseline data? As noted above, EGT is useful in relative but not absolute terms, and a high EGT in and of itself is not a problem. For comparison, all my EGTs are in the 1400s at WOT at takeoff. 

If EGTs suddenly start running much higher than usual on one cylinder on a C model, I would think there is an induction leak.  But then it should be harder to lean without roughness, and CHTs should run higher on that cylinder before trying to lean. If your ability to lean without roughness,  your fuel flow, and your CHTs are all unchanged, then I would blame the probe.  You could prove it by swapping two probes between exhaust risers.  

[kortopates]

Couldn't tell from your post which model you have - apparently a C model from other post.

If you have an engine monitor with downloadable data, open a free account on SavvyAnalysis.com. Then you can upload it and share a link to the data here. Then people can take a look at it. If I knew your N number, I'd take a look to see if I can find your data,  but I don't.

if you only have a single EGT and CHT, well that's pretty useless. Both EGTs and CHTs can vary very widely or have a large spread on the C model due to being carbureted and the legacy baffling. Hard to go much further without seeing the data.

 

[RogueOne]

Do you cruise climb?  I climb at 120MPH indicated/trimmed and cowl flaps full open.  On a hot summer day it makes a big difference in climb.  Takes a little longer to get to cruise altitude but covering more ground while climbing.

[Janat83]

15 hours ago, Hank said:

EGT numbers only matter relative to the peak value, the actual number doesn't mean much (although it's easy to remember when leaning). Keep your CHT and Oil Temp happy innthe climb is the best you can do. You don't mention which model you have, but this is generally done by keeping the mixture forward as you do. Should be 150-200°F richer than peak, but I don't tiuch mine until I'm plenty high.

Thanks for your input, and sorry for not mentioning my airplane model, it's 1968 m20c, my only concern was that I flew 3 hrs before that flight and all was normal, then I landed for refuel and take off again with full throttle and mixture and at 1000ft agl I noticed my EGT gauge showing high near red mark on attached picture (usually on climb I see what's in the picture), i checked my engine monitor and most EGTs was showing around 1400 and when I leaned the mixture the peak was 1570, usually the peak is around 1420 on my airplane, the outside temperature was only 65°F and I usually fly in hotter weather in Socal and never had similar issue, I always maintain 120mph on normal climb which I did yesterday, today I flew again and the EGT is back to normal as you see in picture and everything was perfect, I still don't know what happened on yesterday's flight, the only thing I changed that I added 1qt of oil (oil level was 5.8 yesterday) I don't believe that oil level have anything to do with EGT but this is the only parameter changed since yesterday. 

Edited June 27, 2019 by Janat83

[Janat83]

2 hours ago, RogueOne said:

Do you cruise climb?  I climb at 120MPH indicated/trimmed and cowl flaps full open.  On a hot summer day it makes a big difference in climb.  Takes a little longer to get to cruise altitude but covering more ground while climbing.

Yes Sir, I always climb at 120mph and that happened on one flight yesterday,i have fixed cowl flaps. 

[Janat83]

2 hours ago, kortopates said:

Couldn't tell from your post which model you have - apparently a C model from other post.

If you have an engine monitor with downloadable data, open a free account on SavvyAnalysis.com. Then you can upload it and share a link to the data here. Then people can take a look at it. If I knew your N number, I'd take a look to see if I can find your data,  but I don't.

if you only have a single EGT and CHT, well that's pretty useless. Both EGTs and CHTs can vary very widely or have a large spread on the C model due to being carbureted and the legacy baffling. Hard to go much further without seeing the data.

 

1968 M20c, I'll try to pull up the data from my EDM700, my tail number is N72SK, both Engine monitor and single EGT gauge was showing high temperatures, baffling is pretty good, today's flight was totally normal with same OAT and other parameters, I'll let you know when I pull out the data, thank you very much 

[Janat83]

3 hours ago, DXB said:

I don't fully understand the situation or your description of exactly what happens in cruise.  Title indicates a CHT issue, but statements above describe  a much higher EGT than usual on #1 with no CHT issue at all. Can you clarify?  Also are you SURE #1 EGT is suddenly much higher than usual in comparison to baseline data? As noted above, EGT is useful in relative but not absolute terms, and a high EGT in and of itself is not a problem. For comparison, all my EGTs are in the 1400s at WOT at takeoff. 

If EGTs suddenly start running much higher than usual on one cylinder on a C model, I would think there is an induction leak.  But then it should be harder to lean without roughness, and CHTs should run higher on that cylinder before trying to lean. If your ability to lean without roughness,  your fuel flow, and your CHTs are all unchanged, then I would blame the probe.  You could prove it by swapping two probes between exhaust risers.  

Sorry my bad for the title I was flying the whole day from socal to Seattle and that issue happened on my last flight from Portland to Seattle, the high EGT was almost on all cylinders, all CHTs was in normal range, today I flew again with no issue at all, its weird. 

[carusoam]

The single EGT gauge with no numbers on it, and the ability to adjust its reading from the front...

See the asterisk on the face?

It’s there for a reason.  Related to calibration and peak EGT...

See if you can find a manual for that.

From what I see,

• you had an occurrence with your EGT...
• you have a JPI 
• you can download your data and post it to Savvy 
• share the link here...
• Then look where your Alcor EGT is compared to the JPI EGT in the same tube... take a pic...

The guessing stops, the excess typing stops, the real answers start to come out...

Today we know what you are flying, but tomorrow somebody else will come along and not know... put your airplane details where they can be seen... See the avatar? Put a pic there too...

See if the 90s technology is saying the same thing as the 60s technology...

You have all the equipment to form the answer you are asking about.... it is going  to take a few steps to get there...

Best regards,

-a-

 

[DXB]

55 minutes ago, Janat83 said:

Sorry my bad for the title I was flying the whole day from socal to Seattle and that issue happened on my last flight from Portland to Seattle, the high EGT was almost on all cylinders, all CHTs was in normal range, today I flew again with no issue at all, its weird. 

Something doesn’t add up as you note. High EGTs on all cylinders would point to the carb and/or its mixture control.   High EGTs on all cylinders in cruise with NO effect on CHTs must be a systematic error in the JPI700 - I have experienced similar on my 900 and resetting via the breaker in flight works.  Normal fuel flow at a given power and mixture setting would localize problem to the EGT monitor beyond a reasonable doubt.

Also that Alcor single cylinder gauge can safely be removed to gain 5oz of useful load 

Edited June 27, 2019 by DXB

[Shadrach]

Is it possible that you did not return the key all the way to both after a mag check? Conducting a flight on one mag would cause the symptoms you’ve described.

Edited June 27, 2019 by Shadrach

[DXB]

1 hour ago, Shadrach said:

Is it possible that you did not return the key all the way to both after a mag check? Conducting a flight on one mag would cause the symptoms you’ve described.

Great point! Or maybe a faulty ignition switch or contact with it?

[Shadrach]

1 hour ago, DXB said:

Great point! Or maybe a faulty ignition switch or contact with it?

The fact that it was a one time event leads me to believe it was a one time brain fart on the ignition key. 

Edited June 27, 2019 by Shadrach

[Janat83]

4 hours ago, Shadrach said:

Is it possible that you did not return the key all the way to both after a mag check? Conducting a flight on one mag would cause the symptoms you’ve described.

In flight I checked both mags for proper operation and recycled the engine monitor, tried different power settings and switch tanks, run the fuel pump on and off, I even noticed that on descending the EGT was still higher than what I usually see. 

[DXB]

1 hour ago, Janat83 said:

In flight I checked both mags for proper operation and recycled the engine monitor, tried different power settings and switch tanks, run the fuel pump on and off, I even noticed that on descending the EGT was still higher than what I usually see. 

Stumped.  Please post the data from that flight and normal subsequent one when able.  

[Shadrach]

1 hour ago, Janat83 said:

In flight I checked both mags for proper operation and recycled the engine monitor, tried different power settings and switch tanks, run the fuel pump on and off, I even noticed that on descending the EGT was still higher than what I usually see. 

Did you see a drop on each mag?

All other things being equal, a high EGT reading combined with an unchanged or reduced CHT reading (harder to recognize  as the reduction in CHT is not as dramatic as the increase in EGT) is indicative of a reduction in the speed of the combustion event. 

I cannot envision I scenario where F/A mixture would cause the symptoms you describe.

There are plenty of folks on this board that are smarter than me. Hopefully one of them will be able to help solve your mystery.

Edited June 27, 2019 by Shadrach

[gsxrpilot]

14 minutes ago, Shadrach said:

Did you see a drop on each mag?

All other things being equal, a high EGT reading combined with an unchanged or reduced CHT reading (harder to recognize  as the reduction in CHT is not as dramatic as the increase in EGT) is indicative of a reduction in the speed of the combustion event. 

I cannot envision I scenario where F/A mixture would cause the symptoms you describe.

There are plenty of folks on this board that are smarter than me. Hopefully one of them will be able to help solve your mystery.

I was thinking the same thing.

Did you have your engine monitor in "normalized" mode? Did you notice a nice even EGT rise on each mag?

[FloridaMan]

A bad magneto will cause EGTs to skyrocket, as will a bad plug on a single cylinder. Do a hot mag check. Be quick with it. 

[FloridaMan]

Oops. I just saw that you tried an in-flight mag check. I had an issue once where my IA had my keys, so I used the keys that I keep in my pocket. The weight of the keychain plus turbulence bumped me to a single mag. 

The slowing combustion event strikes me as a possible culprit. I would verify mag timing. Another thing you can do is to try different engine RPMs and see how EGT responds. Lowering RPM gives more time for the mixture to fully combust. Does the factory EGT use the same probe(s) as your engine monitor? If you switch to one mag, does the EGT skyrocket? Does it behave the same for either magneto? On my M20F on my maiden flight home, I noticed high EGT intermittently. When we stopped for gas, we ended up with a dead magneto. The coil had failed and the mag was failing intermittently in flight and we believe that it was the cause for the periods of high EGTs. 

[Shadrach]

1 hour ago, FloridaMan said:

 The weight of the keychain plus turbulence bumped me to a single mag. 

Yeah turbulance I tell you! Turbulance...and a heavy key chain...yeah...That's the ticket...That's my story and I'm sticking to it!

[Janat83]

Sorry for late reply, I just came back from my long flights , here's the link for all flights

https://savvyanalysis.com/my-flights/1006896/655e906d-7265-4c61-bbef-2e4444a0f55d

Flight #11 is the one that I had high EGT on its duration was 1hr 39min

I did 4 flights and more than 8 hours since that flight and all was normal, except last 2 flights I had high CHT warning on climb-out (maybe because of higher OAT!!)

Thanks all for your help, i'm still new on this so pleas excuse my shallow knowledge.

[Shadrach]

4 hours ago, Janat83 said:

Sorry for late reply, I just came back from my long flights , here's the link for all flights

https://savvyanalysis.com/my-flights/1006896/655e906d-7265-4c61-bbef-2e4444a0f55d

Flight #11 is the one that I had high EGT on its duration was 1hr 39min

I did 4 flights and more than 8 hours since that flight and all was normal, except last 2 flights I had high CHT warning on climb-out (maybe because of higher OAT!!)

Thanks all for your help, i'm still new on this so pleas excuse my shallow knowledge.

I think you’re a bit confused about the relationship between OAT and EGT. All other things being equal, higher OAT usually means lower EGT. 

Edited July 1, 2019 by Shadrach