reported Engine overheating?

[Doughguy]

Was flying mp today and my doras engine died twice today once i accelerated past 3000 u/min at about 6000m

on the first t/o i warmed her up to about 70°C and rolled to the runway and took off with about 90°C. 

Climbed with 3250 until i reached 400kmh then throttled back to 3000 u/min

At 6k i kept crusing with about 2700 u/min, all fine, stable. once i pushed past 3000 u /min i just noticed slight vibrations then it immediatelly died.

 

On the 2nd i let her warm up to 90°C then rolled off and  took off with 3250 but throttled back to 3000 once i reached 300kph and climbed to 6k.

All fine and swell. 100°C constantly at 2700 u/min. Pushed my throttle forward past 3000 u/min. Same thing. Died almost instantly.

I just noticed that radiator flaps were closed, but upon t/o and flight they were wide open.

I did not touch them on both occasions.

Track file

https://1drv.ms/u/s!AqPXiw0yQDEVgkquAPHQyTYvwzpb?e=f20gTN

 

It is strange as i basically t/o with the same procedures and never experienced this.

 

Whoops sorry, just noticed wrong subforum @NineLine  please be so kind and move it into the bugs/problemd section?

Edited September 22, 2023 by Doughguy

[Art-J]

Not a MP guy myself, can't figure out how to play this replay track of yours. A shot in the dark though: are you sure you turned on water injection? Both the circuit breaker on the right panel and the switch on the left one? Is it available on this server you played at all? I recall reading some servers limit MW50 availability.

On the other hand, having inop MW injection shoulnd't kill the engine so fast I think (?), as the regulator drops the manifold pressure anyway, from 1.9'ish to 1.7'ish.

Just tried to replicate what you did, but using stock Channel cold-start mission and taking off immediately after warm-up to 50 degrees. Then spent some time about 6500 m flying at 3250 RPM with MW on and off. In both attempts the engine ran fine for a few minutes so I'm at loss about what could've happened in your case.

[Doughguy]

Yeah the mw50 isnt available on 4ya. Im tryin to figure out what happened. Ive not touched the mw50 switch or radiators. Popping the cb's for the mw50 shouldnt have an effect if you dont turn on mw50. Ive not used an dora with the mw50 tank filled with b4. So no switching aswell. 

Someones suggested taking off with 50 deg on oil and coolant and he ran fine. But appatently he ran into some engine failures aswell just recently.

I tried sp cold start with different temps and she was running fine.

Even with an air spawn 90 deg temps initially and its all good.

I literally had no probs with her before but 2 dead engines in the same sortie is pretty rare.

Edited September 22, 2023 by Doughguy

[NineLine]

Moved, thanks. ALso I will try and take a look soon.

[Doughguy]

@NineLine

Could you have a look? My engine died again today with the rpm around 2700. did a proper start up and didnt really abuse the engine afaik.

https://1drv.ms/u/s!AqPXiw0yQDEVgk3nzjYrykHjPfJG?e=nMMuhq

Engine Failure occure at the end of the track

Edited October 31, 2023 by Doughguy

[Hobel]

vor 4 Stunden schrieb Doughguy:

@NineLine

Could you have a look? My engine died again today with the rpm around 2700. did a proper start up and didnt really abuse the engine afaik.

https://1drv.ms/u/s!AqPXiw0yQDEVgk3nzjYrykHjPfJG?e=nMMuhq

Engine Failure occure at the end of the track

 

What minute exactly? and how long is the track?

[Doughguy]

The last 10 mins. Its a rather long track unfortunately. Was circling over st. Lo when the engine started making funny noises and then cuts out from overheating. No idea why tho as ive not been pushing it anywhere near over 3000 past the start of the 2nd sortie iirc. Not touched the radiators etc.

Edited November 1, 2023 by Doughguy

[NineLine]

12 hours ago, Doughguy said:

@NineLine

Could you have a look? My engine died again today with the rpm around 2700. did a proper start up and didnt really abuse the engine afaik.

https://1drv.ms/u/s!AqPXiw0yQDEVgk3nzjYrykHjPfJG?e=nMMuhq

Engine Failure occure at the end of the track

 

I'll take a look soon, thanks 

[Doughguy]

Cheers!

[Hobel]

vor 6 Stunden schrieb Doughguy:

The last 10 mins. Its a rather long track unfortunately. Was circling over st. Lo when the engine started making funny noises and then cuts out from overheating. No idea why tho as ive not been pushing it anywhere near over 3000 past the start of the 2nd sortie iirc. Not touched the radiators etc.

 

last 10 minutes of what?
of a total of 30 minutes or 2 hours? knowing this beforehand makes it much easier to see the problem, depending on whether I can run the video only in real time or maxwith 2x time lapse and if I then miss the problem....

[NineLine]

14 hours ago, Doughguy said:

Cheers!

I am only part way through your track (I like to watch them a normal speed so I tend to take breaks :D) but I noticed a lot of time spent over 3000 RPM below 7500 m. 

Where I am at right now though, your coolant looks ok, but your oil is a bit high. 

[grafspee]

11 hours ago, NineLine said:

I am only part way through your track (I like to watch them a normal speed so I tend to take breaks :D) but I noticed a lot of time spent over 3000 RPM below 7500 m. 

Where I am at right now though, your coolant looks ok, but your oil is a bit high. 

3250 w/o mw50 is also climb power with 30min limit so unless he was staying at that power +30min, this shouldn't not be the problem. Ofc if dcs manual matches what we have in game.

[NineLine]

3 hours ago, grafspee said:

3250 w/o mw50 is also climb power with 30min limit so unless he was staying at that power +30min, this shouldn't not be the problem. Ofc if dcs manual matches what we have in game.

No and as I said the point I am at in the track temps look mostly ok, but it's still outside recommended procedures.

[grafspee]

24 minutes ago, NineLine said:

No and as I said the point I am at in the track temps look mostly ok, but it's still outside recommended procedures.

No, Manual do not match what we have in game or No, 3250 is not climb power, or No using 3250 for less then 30min for not climbing will damage engine. I'm not sure where this "no" fits is it answer to all what i said or to one particular thing.

Edited November 2, 2023 by grafspee

[NineLine]

No as in no I am not saying the manual doesn't match the sim. But the manual does say max continuous under 7500m is 3000. I would suggest anything other than climb is somewhat abusive and worth noting.

And again, I have not gotten to the failure yet. I wasn't able to get back to the track last night.

[Doughguy]

On 11/1/2023 at 12:50 PM, Hobel said:

last 10 minutes of what?
of a total of 30 minutes or 2 hours? knowing this beforehand makes it much easier to see the problem, depending on whether I can run the video only in real time or maxwith 2x time lapse and if I then miss the problem....

The whole track. after my engine siezed and i made a belly land i exited the server. i dont have the correct timeframe sorry

[Hobel]

Oka I am confused.

3000 rpm continuous power is clear.

Max 30min 3250 rpm  only over 7500m?

And under 7500m what is the highest rpm web limit?
i thought 30min 3250rpm should also apply below 7500m?

If it doesn't then what is max rpm limit below 7500m?

[Doughguy]

16 hours ago, NineLine said:

I am only part way through your track (I like to watch them a normal speed so I tend to take breaks :D) but I noticed a lot of time spent over 3000 RPM below 7500 m. 

Where I am at right now though, your coolant looks ok, but your oil is a bit high. 

Hm.. i usually climb with 3000 after i reach 300kph upon start and climb to 6k with said settings.

Once im at said alt i throttle back to about 2800, and on egress to 2500 depending on fuel etc.

But yea for combat i also push it to 3250 but not all the time but i rarely fly her above 6k. shes quite a fuel guzzler.

 

On the latest track the failure occured on the last few minutes. I dont recall it anymore on my first track im afraid, but i figuerd i mightve indeed have a double bind for the mw50 switch and that mightve killed the engine iirc. but i cant really pin point that as ive noticed that days later and it might be some wonky stuff after an update.

[grafspee]

6 minutes ago, Hobel said:

Oka I am confused.

3000 rpm continuous power is clear.

Max 30min 3250 rpm  only over 7500m?

And under 7500m what is the highest rpm web limit?
i thought 30min 3250rpm should also apply below 7500m?

If it doesn't then what is max rpm limit below 7500m?

It is easy max continuous up to 7500 is 3000rpm above 3250rpm. 30 min limit for 3250rpm below 7500m, above no limit

[Doughguy]

1 minute ago, grafspee said:

It is easy max continuous up to 7500 is 3000rpm above 3250rpm. 30 min limit for 3250rpm below 7500m, above no limit

Thats i fly by.

[Hobel]

vor 2 Minuten schrieb grafspee:

It is easy max continuous up to 7500 is 3000rpm above 3250rpm. 30 min limit for 3250rpm below 7500m, above no limit

Ah good, then I've understood it correctly, thanks to you.

[grafspee]

45 minutes ago, Doughguy said:

Hm.. i usually climb with 3000 after i reach 300kph upon start and climb to 6k with said settings.

Once im at said alt i throttle back to about 2800, and on egress to 2500 depending on fuel etc.

But yea for combat i also push it to 3250 but not all the time but i rarely fly her above 6k. shes quite a fuel guzzler.

Proper climb procedure from DCS Dora manual

If you climb at 3000 rpm you are below climb power level so you are not abusing engine.

I don't buy claims that not climbing Dora with climb power which is 3250 rpm is engine abuse at all since climbing at 3250 with 280-290 kph is way more abusive then flying at same power at higher speed due to much better cooling. As long as you not running engine +30min at 3250rpm no engines will be harmed.

If someone wonder, i assume that that 3min limitation if for 3250rpm + mw50.

Ofc if DCS manual tells the truth about sim model.

 

Edited November 2, 2023 by grafspee

[NineLine]

I think you are misunderstanding what I am saying, I never said there was anything wrong with climbing at that level, but the use of over 3000 during flight/combat etc is not recommended below 7500m, ASWELL I am not saying that is the issue here, I haven't finished the track, what I am reporting is my concerns with the flight based on my normal procedures with the Dora and what the manual says. I don't doubt you can push it farther, but as with anything pushing harder can lead to more issues late. 

53 minutes ago, Doughguy said:

Hm.. i usually climb with 3000 after i reach 300kph upon start and climb to 6k with said settings.

Once im at said alt i throttle back to about 2800, and on egress to 2500 depending on fuel etc.

But yea for combat i also push it to 3250 but not all the time but i rarely fly her above 6k. shes quite a fuel guzzler.

 

On the latest track the failure occured on the last few minutes. I dont recall it anymore on my first track im afraid, but i figuerd i mightve indeed have a double bind for the mw50 switch and that mightve killed the engine iirc. but i cant really pin point that as ive noticed that days later and it might be some wonky stuff after an update.

Yeah I didnt make it through the track yesterday, and my game timed out over night so back to the start we go

[Hobel]

vor 8 Minuten schrieb NineLine:

but the use of over 3000 during flight/combat etc is not recommended below 7500m,

And what is the limit below 7500m?
Is 30min for 3250rpm lvl flight below 7500m correct or not?

[grafspee]

26 minutes ago, Hobel said:

And what is the limit below 7500m?
Is 30min for 3250rpm lvl flight below 7500m correct or not?

This is what @NineLine linked earlier.

This refers only to Cruise, doing combat there is no single reason in DCS manual to not use 3250 in climb or in combat.