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High CHT?


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Simon, I'm not sure what you have established, but this is what I am seeing:

After a few flights with correct use of carb heat, the CHT temperature will climb above redline in cruise. A maintenance inspection post flight does not reveal any problems. Using the Katana reset tool fixes it.

After a few more flights, conducted with absolutely no use of carb heat (because someone pointed to that as the possible culprit) CHT temperatures remain low.

I'm not a beta tester, so I haven't flown the exact same flight over and over again with the same date/time settings etc. Obviously something else could be causing this, but I don't think so.

I understand that not everyone is having this problem. I'm posting about my experience mainly to give Marcel another data point. If it helps him fix it, fine - if not, I'll just have to stay alert so I know where to put down in case the engine quits.

absolutely correct trisager... and I do experience it the same way you do without any need to report anything else or due to wrong pilotage or whatever other exuses is being thrown at us.. I do I opperate according to sound principles and Carb heat usage (even at teh most conservative usage) once you have pulled that knob even for 3 minutes, suddenly the CHT temps will rise considerably in same flight and subsequent flights and I will experience engine failure within 3 hours after I initially used the carb heat even if it was just for that 3 minutes and never again.

Carb heat knob used = excessive CHT temps after carb usage = engine failure.. (all within the span of 3 hours)

tested numerous times and always from reset version. brand new... no other stupid excuse usage/pilotage etc..

When I dont touch carb heat I have flown easilly 10 hours without an inkling of any high CHT temps and very little engine wear

How do I know.

I check the data.cfg file and according to data.cfg file

no carb heat usage

[TIME]

TIME_FLIGHT=7.861111

TIME_ENGINE=9.827776

TIME_ENGINE_OVERHAUL=9.827776

TIME_AIRFRAME=9.827776

LANDINGS=27.000000

[CONDITIONS]

CONDITION_ENGINE=94.129684

with carb heat used 6 minutes in first flight (last minutes of 1st flight and during descent and landing and then switched of after landing) and then not used again during next 2 flights (initially from 100% correct reset value)

[TIME]

TIME_FLIGHT=1.26415

TIME_ENGINE=1.765522

TIME_ENGINE_OVERHAUL=1.765522

TIME_AIRFRAME=1.765522

LANDINGS=3.000000

[CONDITIONS]

CONDITION_ENGINE=57.698643

So Simon,

now please explain to me how that happen if I fly the simulation exactly the same during tests..

So please stop giving excuses like bad pilotage and other stuff as the result of the excessive engine wear.. we are not that stupid..

So there is NOTHING ELSE that might be going on that we are not reporting, which can be contributing....!!!

It has been proven time after time as you have been stating, use CH `correctly` according to the MS model, and the `problem` DO CONTINUE to exist exist. That would seem to indicate that even when proper pilotage is instigated, CH is a an issue as well as the following excessive engine wear due to excessive CHT.

It is not about excessive carb usage etc or whatever stupid reason u try to give for the excessive engine wear..

there is a problem with the simulation.. bottom line: well at least for me, and I have proven it..! so stop making excuses.

this a not criticizing a bloody awesome product, it is a valid concern we share, so please see this in this light and stop thinking we are out to try and degrade the katana.. we are just trying to make it flawless like the rest of the product that Marcel has created for us and that have broken every bloody FSX boundries..!

So Simon, if you do not have any constructive value to add to this issue, please refrain from posting here and rather let Marcel deal with it. At least he seem to grasp the bigger picture to what we are experiencing here.

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absolutely correct trisager... and I do experience it the same way you do without any need to report anything else or due to wrong pilotage or whatever other exuses is being thrown at us.. I do I opperate according to sound principles and Carb heat usage (even at teh most conservative usage) once you have pulled that knob even for 3 minutes, suddenly the CHT temps will rise considerably in same flight and subsequent flights and I will experience engine failure within 3 hours after I initially used the carb heat even if it was just for that 3 minutes and never again.

Carb heat knob used = excessive CHT temps after carb usage = engine failure.. (all within the span of 3 hours)

tested numerous times and always from reset version. brand new... no other stupid excuse usage/pilotage etc..

When I dont touch carb heat I have flown easilly 10 hours without an inkling of any high CHT temps and very little engine wear

How do I know.

I check the data.cfg file and according to data.cfg file

no carb heat usage

[TIME]

TIME_FLIGHT=7.861111

TIME_ENGINE=9.827776

TIME_ENGINE_OVERHAUL=9.827776

TIME_AIRFRAME=9.827776

LANDINGS=27.000000

[CONDITIONS]

CONDITION_ENGINE=94.129684

with carb heat used 6 minutes in first flight (last minutes of 1st flight and during descent and landing and then switched of after landing) and then not used again during next 2 flights (initially from 100% correct reset value)

[TIME]

TIME_FLIGHT=1.26415

TIME_ENGINE=1.765522

TIME_ENGINE_OVERHAUL=1.765522

TIME_AIRFRAME=1.765522

LANDINGS=3.000000

[CONDITIONS]

CONDITION_ENGINE=57.698643

So Simon,

now please explain to me how that happen if I fly the simulation exactly the same during tests..

So please stop giving excuses like bad pilotage and other stuff as the result of the excessive engine wear.. we are not that stupid..

So there is NOTHING ELSE that might be going on that we are not reporting, which can be contributing....!!!

It has been proven time after time as you have been stating, use CH `correctly` according to the MS model, and the `problem` DO CONTINUE to exist exist. That would seem to indicate that even when proper pilotage is instigated, CH is a an issue as well as the following excessive engine wear due to excessive CHT.

It is not about excessive carb usage etc or whatever stupid reason u try to give for the excessive engine wear..

there is a problem with the simulation.. bottom line: well at least for me, and I have proven it..! so stop making excuses.

this a not criticizing a bloody awesome product, it is a valid concern we share, so please see this in this light and stop thinking we are out to try and degrade the katana.. we are just trying to make it flawless like the rest of the product that Marcel has created for us and that have broken every bloody FSX boundries..!

So Simon, if you do not have any constructive value to add to this issue, please refrain from posting here and rather let Marcel deal with it. At least he seem to grasp the bigger picture to what we are experiencing here.

Very well. I will let you handle it.

Except to say that in my case correct use of carb heat does NOT - repeat NOT - cause the data.cfg to display any significant degradation:

[TIME]

TIME_FLIGHT=35.473749

TIME_ENGINE=18.450138

TIME_ENGINE_OVERHAUL=18.450138

TIME_AIRFRAME=18.450138

LANDINGS=37.000000

snip

[CONDITIONS]

CONDITION_AIRFRAME=99.000000

CONDITION_CANOPY=99.000000

CONDITION_WING_LEFT=99.000000

CONDITION_WING_RIGHT=84.627984

CONDITION_ELEVATOR=99.000000

CONDITION_RUDDER=99.000000

CONDITION_FLAPS=95.125668

CONDITION_ENGINE=91.483042

CONDITION_GENERATOR=98.973918

CONDITION_BATTERY=98.982373

CONDITION_FLAPS_MOTOR=99.000000

STATUS_BRAKE_LEFT=98.913287

STATUS_BRAKE_RIGHT=98.904890

CONDITION_GEAR=98.997311

CONDITION_PROPELLER=99.000000

CONDITION_SPINNER=99.000000

CONDITION_STARTER=99.000000

CONDITION_GEAR_NOSE=99.000000

CONDITION_GEAR_LEFT=98.875313

CONDITION_GEAR_RIGHT=98.875313

CONDITION_TIRE_NOSE=91.438718

CONDITION_TIRE_LEFT=91.438635

CONDITION_TIRE_RIGHT=91.438635

CONDITION_WHEEL_FAIRING_NOSE=100.000000

CONDITION_WHEEL_FAIRING_LEFT=100.000000

CONDITION_WHEEL_FAIRING_RIGHT=100.000000

STATUS_VSI_GLAS=0.000000

CONDITION_FUEL_PUMP=97.864309

CONDITION_MECHANICAL_FUEL_PUMP=97.073181

CONDITION_FINGER_FILTER=96.065734

CONDITION_KX125TSO.1=71.500000

CONDITION_KT76A.1=73.500000

OIL_CAP=1.000000

CONDITION_MAGNETO_LEFT=98.984937

CONDITION_MAGNETO_RIGHT=98.985207

COOLANT_CAP=1.000000

PRESSURE_TIRE_LEFT=2.400000

PRESSURE_TIRE_NOSE=1.900000

PRESSURE_TIRE_RIGHT=2.400000

CONDITION_AILERONS=84.627984

CONDITION_FLAP_MOTOR=94.038850

ACCESS_DOOR_OIL_ANGLE=0.000000

OIL_COWLING=4.159413

OIL_WINDOW=10.398533

CONDITION_M803A=100.000000

CONDITION_GPS500=99.000000

So I guess flying it right, beats flying it wrong and blaming the developer...

I am interested in your explanation as you have assumed the role or arbiter in this matter.

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Very well. I will let you handle it.

Except to say that in my case correct use of carb heat does NOT - repeat NOT - cause the data.cfg to display any significant degradation:

So I guess flying it right, beats flying it wrong and blaming the developer...

I am interested in your explanation as you have assumed the role or arbiter in this matter.

:hello-bye_s:

Ok bye bye then... rather go annoy other people

We will take it up with Marcel, who by the way we do not blame.... as this is not about blaming/bashing a person. it is a concern where flying it right, creating wrong results..

you must be one hell of a depressed person to only see "negatives" in every post..

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:hello-bye_s:

Ok bye bye then... rather go annoy other people

We will take it up with Marcel, who by the way we do not blame.... as this is not about blaming/bashing a person. it is a concern where flying it right, creating wrong results..

you must be one hell of a depressed person to only see "negatives" in every post..

I thought you were taking over? Please provide an explanation, not obfuscation. If you can't, then it is you who should excuse yourself from the conversation.

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Please provide an explanation, not obfuscation.

Simon, This is a support forum. It is legitimate to provide a problem description without an attached explanation.

I appreciate that you are not seeing this, and that you are convinced that our problems are due to poor pilot skills. I tend to think that there is a something in the Katana that causes this issue on some setups (like the CTDs being reported in another thread, which I assume you are not seeing eiter), and I'm posting with the hope that Marcel will consider it and see if he can come up with an explanation.

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Simon, This is a support forum. It is legitimate to provide a problem description without an attached explanation.

I appreciate that you are not seeing this, and that you are convinced that our problems are due to poor pilot skills. I tend to think that there is a something in the Katana that causes this issue on some setups (like the CTDs being reported in another thread, which I assume you are not seeing eiter), and I'm posting with the hope that Marcel will consider it and see if he can come up with an explanation.

Correction, this is a DISCUSSION forum. The support is elsewhere.

On that basis I consider it perfectly valid to continue the DISCUSSION about whether this is an error of omission or skill, rather than assume that it is a bug that needs fixing...

Obviously bliksimpie will expand on this once he has actually decided to answer my question.

For now, as you say, this is a problem that afflicts some, but not many. In the absence of evidence to support a final conclusion either way, the occasional nature of this issue could be user error. And therefore warrants repeating just as much as the claim that it is a product issue.

And no, I don't see any CTD's. But then I don't bugger about with my system like a blind man in the dark, unlike some people.

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Correction, this is a DISCUSSION forum. The support is elsewhere.

Quoting the Aerosoft web page, "Forums: Our preferred way of doing support and by far the fastest ..."

On that basis I consider it perfectly valid to continue the DISCUSSION about whether this is an error of omission or skill, rather than assume that it is a bug that needs fixing...

Yes, fine by me. But you may want to consider the remote possibility that there could be a tiny issue with this product that is affecting some but not you. And that your assumption that the rest of this world's population is too dumb to breathe without your help may not be warranted...

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Correction, this is a DISCUSSION forum. The support is elsewhere.

On that basis I consider it perfectly valid to continue the DISCUSSION about whether this is an error of omission or skill, rather than assume that it is a bug that needs fixing...

Obviously bliksimpie will expand on this once he has actually decided to answer my question.

For now, as you say, this is a problem that afflicts some, but not many. In the absence of evidence to support a final conclusion either way, the occasional nature of this issue could be user error. And therefore warrants repeating just as much as the claim that it is a product issue.

And no, I don't see any CTD's. But then I don't bugger about with my system like a blind man in the dark, unlike some people.

yes I have only one answer for u.. "you seem to have a bit of knowledge around the real world katana, but obviously that is where it end as u know %^&* about support/proper meaningful discussions that could lead to solving a real issue for some of us and you and your issue do not warrant any explanation from me"

:byesad_s:

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Quoting the Aerosoft web page, "Forums: Our preferred way of doing support and by far the fastest ..."

Yes, fine by me. But you may want to consider the remote possibility that there could be a tiny issue with this product that is affecting some but not you. And that your assumption that the rest of this world's population is too dumb to breathe without your help may not be warranted...

Yes, and to facilitate that Aerosoft provide a multiplicity of forum, so that the focus can be given. This, however, is the discussion forum, defined by the publisher as:-

`Comments, Suggestions, small talk`

And most assuredly NOT a support forum. For that we have the Problems / Bugs / Issues forum, whose role is defined thus:-

`Post your bug reports or issues your having here.`

So ryanbatc, who is no fool and no stranger to the delineation of forums for a particular purpose, chose to pose his question here. And here is where it will be DISCUSSED. Until such time as YOU prove it IS a BUG. Whereupon we can all decamp to the correct forum to consider the implications.

Now, about that proof of yours? You're very good at trying to deflect attention away from the issue, aren't you?

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Now, about that proof of yours? You're very good at trying to deflect attention away from the issue, aren't you?

Like I said, I have described the problem as I experience it. No proof of any kind is required to post in a support forum - or a discussion forum for that matter.

Despite all the noise you continue to make, I expect that Marcel will eventually read it and consider it. That is what matters, really.

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Like I said, I have described the problem as I experience it. No proof of any kind is required to post in a support forum - or a discussion forum for that matter.

Despite all the noise you continue to make, I expect that Marcel will eventually read it and consider it. That is what matters, really.

My reply was to the self-appointed arbiter, not you. I provide evidence, not proof. Evidence of no problem is as indicative as proof that one exists.

The discussion shall continue.

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wacko.gifwacko.gifwacko.gifwacko.gifwacko.gifrolleyes.gifrolleyes.gifrolleyes.gifohmy.gifohmy.gifohmy.gif

trisager and bliksimpie, guys Rule #1 on these forums Don't reply to anything by you know who. wink.gif

yeah you right... but we need to get the point over to Marcel that we do have an issue here to be discussed in more detail with some good common sense from Aerosoft support side... and we kept being giving sh!t excuses for the issue at hand from nothing but a snave. so lets rephrase Rule #1: "Don't reply to anything by the retard you know who"

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So, cornered by the absence of evidence you resort to increased use of emoticons, total ignorance of the purpose of the discussion and abrogation of the personal responsibility to justify your opinions with evidence?

How verrry helpful to the discussion...

Still, now you're ignoring me, you won't find the fact that I've just managed to make the engine drop 7 points in half an hour by the simple expedient of running CH in 22 Celsius ambient with a dew point at zero and maintaining near-full MP for climb and cruise at 7,500ft.

In other words, I've just proved that flying it wrong contributes to engine wear.

I continue to await your proof that flying it right also does so.

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Hi guys!

Sorry but I have to add some thermodynamics (well what I do remember!!!!) into this thread.

When you apply the carburettor hear, it increases the inlet air temperature to the engine, as a result the density of the air increases hence a modification on the fuel/air ratio (that is why the drop in the power output). This modification on the fuel/air ration plus the evidence on increases on the CHT suggest that the automixture simulated in the Rotax is too lean and is unable to adapt the mixture to the new inlet temperature. Consequently the engine is experiencing detonation (please if this is not the proper name of the phenomenon fell free to added) which is the cause of the degradation and eventually the complete failure of the engine.

For real pilots this is the reason why you should avoid leaning until CHT pick (perfect air/fuel ratio) and always fly your plane with a touch of rich mixture.

For those with the problem, you can add the weather and plane condition to your post so will be easy to find where the possible bug is.

For those with no problem, apart from flying on the numbers another good reason could be the weather conditions where you are flying on....

This comments are true if Marcel and 4X have used the exact thermodynamics tables necessarily to provide a perfect fuel/air ratio under given weather conditions and without including this subtle change on the inlet air temperature.

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Sorry mate, but you are wrong in both your understanding of thermodynamics, and how the impact of carb heat affects the engine.

Carb heat does NOT heat the inlet air (not in Rotax engines, other aviation engines are different).

Increase in temperature LOWERS air density, not increases it.

The stoichiometric ratio remains the same, regardless of the air temperature.

The Rotax system uses a heated carb throat to provide the heating effect. Heat is applied from a piped feed taken from the coolant, heating the carb body, not the air that flows through it. The cowling and position of the Bings in the Katana mean that the air that flows into the engine is ALWAYS heated. The icing of a Rotax carb is caused by condensate freezing in the throat or butterfly as a result of the velocity of the inducted air increasing, and causing ice to form typically on the butterfly valve and carb throat. By raising the temperature any ice does not adhere, so there is no accumulation.

The air does not freeze. So density effects are irrelevant as far as the air itself is concerned.

Carb ice on a Bing

sd_img_ch_ice.jpg

carb heat kit

sd_img_ch.jpg

Using this system, carb heat may be applied at all times with no detrimental effect, except for a minor reduction in power. However, the Rotax 912S is NOT prone to carb icing because the carb inlets receive warmed, dried air from under the cowling, not via a direct, pressurised cold feed from the exterior of the aircraft. I've never experienced it, even in the normally cold and wet British climate.

Marcel, on the other hand, did have it on a flight in a Katana for development purposes. So it CAN happen.

The discussion here is whether the application of carb heat directly causes engine status degradation, or whether inappropriate use of carb heat is part of a package of user errors that cumulatively cause same.

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Increase in temperature LOWERS air density, not increases it.

UUpppppssssss I got it complete wrong there....

Thanks for your feedback and how the Katana engine works

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The discussion here is whether the application of carb heat directly causes engine status degradation, or whether inappropriate use of carb heat is part of a package of user errors that cumulatively cause same.

and it was solved by Marcel even after some major scepticism from a snave when four very vocal complainants apparently misrepresent, misjudge, misreported this... and was just being plain miserable..

We are so fortunate to have Marcel here who is willing to listing to his customers even though it might have been "bad pilotage" he still took the time to investigate instead of just try to shut us up with ridiculous and unfounded statements.. Now that is "SUPPORT".. willingness to listen.. what a man..!

To see the final answer to this "discussion" go to this post to see where it was resolved quickly efficiently and very professional

http://forum.aerosoft.com/index.php?/topic/45658-carb-heat-high-cht-engine-self-destruct/

:bow_down2_s:

thanks Marcel...!

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