correct as-is Engine over heat issue is back

[NineLine]

43 minutes ago, Lixma 06 said:

If 'our' P-51 was sent into combat there would be a placard in the cockpit that read 'AVOID VERTICAL MANEOEUVRES LIKE THE PLAGUE'. 

But you don't need to avoid them like the plague, you need to fly them appropriately. I did four or five stall turns without blowing up my engine, you just need to be mindful of your temps and such.

 

53 minutes ago, Reflected said:

Also, why isn't anything like this mentioned in training materials

It sort of is, you need to maintain proper temps and fly your gauges and stick to the limits of the aircraft, there are a lot of ways to break the engine in the P-51 that are not listed specifically in the manuals.

[Doughguy]

vor 20 Minuten schrieb Reflected:

So I guess it's not true then?

no you just dont get my point.
 

Zitat

you just dismissed Goody's book, so I guess you1re not interested in historical sources.

neither did i dismiss valid historical sources. but it simply is not stated in the manual. period.

just because something is not expressedly written in a manual, doesnt make it untrue. thats what you´re negating.

Zitat

Here's a period instruction video. "Any prohibited maneuvers?" - they're only worried about structural damage on the wings and oil supply during negative g-s.

How about this: videos and specs are very specific to the specs of a 51. you dont need to repeat bfm etc in every manual.

Any manual gives cornerstones about the specific vehicle. Not general do´s n donts of any aircraft that will apply, which a steep climb and resulting engine temperature rise is.
Aswell it wont state: dont do dives for too long or your wings will fall off. it talks about precise altitudes and dive speeds.
Just as it states specific temperatures which should not be exceeded.

That a stall will induce a lack of cooling, and hence temperature rise to a point itll fry the engine, is something indicated by that fact that the manual explicitly states how its coolin system works. Speed>Airflow>Cooling.

The rest is a bit of common sense and an instructor tellin you so, so you´ll have it in the back of your mind.

Edited February 16, 2022 by Doughguy

[Reflected]

@NineLine & @Doughguy I get your arguments: so it was something so basic, that it wasn't P-51 (Spit) - specific enough to be mentioned in trainings and manuals.

But then, why isn't this issue present on any other warbird in DCS? If it was so general and basic?

In DCS is very 'Merlin-specific', so either all other aircraft are too forgiving or these are too unforgiving. If the contrast between these types and others had been so stark, then there would need to be sources mentioning this, but there is none. And that is my argument. It's quite possible that it's all correct, and as you said, it was something very basic and generally applicable, but then we have a different issue in DCS: all other warbirds. OK, let's not compare them to the 109, but to the P-47, the aircraft that many pilots flew before transferring to the P-51.

If I had to show anyone in DCS how to transfer from the P-47 to the P-51, this instruction would be written in bold red letters, because it's something new, something the player didn't have to keep in mind while flying the P-47.

You see what I mean?

[NineLine]

No because the P-47 is a different engine, and different cooling requirements, and anything with an engine you are flying you would still monitor the gauges and fly within the limits. 

[Reflected]

4 hours ago, NineLine said:

No because the P-47 is a different engine, and different cooling requirements, and anything with an engine you are flying you would still monitor the gauges and fly within the limits. 

I completely agree with you there.

But this defeats your previous argument saying it's not mentioned in any of the Spit/ Mustang manuals, films, memoirs, anecdotes because it's  such a basic thing, that's true for every engine.

I'm not debating the fact that you have to keep an eye on the temps and manage your engine carefully. I'm debating the fact that a mere 4-5 seconds of tumbling out of control should be enough to break your engine permanently.

[NineLine]

Yet the fact remains, that you will overheat the engine flying like you showed, you cannot bring the aircraft to a standstill in mid air with the RPM maxed out and expect it to survive. Again, the limits are in the manual, temps and RPM and MP, by abusing one, you go well over the limits on another. Set the P-51D to 2700 RPM and 46 MP, and you can do stall turns to your heart's content. 

[Reflected]

I can't: p51cooling2.trk

and here I'm flying at combat settings, but as the speed drops below 100 mph, I pull the throttle to idle - consequently RPM also drops: p51cooling3.trk

Edited February 16, 2022 by Reflected

[Doughguy]

Zitat

In DCS is very 'Merlin-specific', so either all other aircraft are too forgiving or these are too unforgiving

to be frank ive not flown any other aircraft so far in dcs apart from the öony and anton.

youre literally comparing apples and oranges. each airplane has its very specific kinks. if its so merlin specific as you say, guess what, i guess it is? cause... its a very specificly build engine? and certainly not a radial engine and or a jumo. the prototype anton also had problems with temp as its cooling was ineffective. 

as for the lack of resources regarding the downside of the pony, well historical accounts of pilots should be taken with a grain of salt without smudgin their effort.

they simply had the specs hammerd in and told not what to do that they did watch the instruments very closely. some sure will not and not live on to tell the story or maybe even simply not said theyve screwed the engine because they didnt pay attention. sure mightve had some consequences screwing government property.

its with every other kinks of any other machine. not everything in the manual explicitly or alltogether cause if you can add 1 + 1 youll understand what "dont go below the temps red line" means.

then again..again manual again might be "faulty", not takin in account some numbnut might not do the math...

i think we can agree that high temps in an engine are bad. regardless of engine and plane. not cooled not working. its a commonality. 

specs just differ by each airframe.

just as turn ratio and stall characteristics and the tendency to get ones wings ripped off.  not everything of this is expressedly written in manuals.

Edited February 16, 2022 by Doughguy

[NineLine]

1 hour ago, Reflected said:

I can't: p51cooling2.trk

You can't keep the power up when the plane slows to a stop, even on my second vertical, I actually thought I was going to overheat the engine as I left the power on too long. 

 

[Reflected]

Yes, you can do stall turns at max continuous and closing the throttle to 0 as the speed drops below 100. But that's not a realistic combat scenario. I have yet to hear a convincing argument why this behavior is correct. Above are listed several counter arguments. Pilots' notes, memoirs, anecdotes, training videos, you name it. And the only counter argument I've heard is 'You can't expect to cross the red line without any consequence'.

No, I'm not expecting that. But I do expect being able to stall out and tumble for 4-5 seconds without permanently destroying the engine. Who knows, maybe the the temp took longer to climb and cross the red line? Maybe the prop wash is not factored in DCS? I can't see what's under the hood, I just see the symptom, a behavior that looks unrealistic to me based on the below and above mentioned arguments:

- The Spit MkI's negative g cutout is all over the news, yet a way more dangerous and permanent issue is not? This gave a marked advantage to the 109. I guess not killing the engine in the vertical is a more marked advantage yet never mentioned.

- Both the Spit and the Mustang was regularly ran up to full throttle on the ground (0 airspeed) - see video below as an example. In this track, it took me only 15 seconds at full throttle to cause permanent damage: p51cooling4.trk

- None of the pilots' notes mention this danger, apparently because it's not Merlin specific, but the other warbirds in DCS are not prone to this, because it's Merlin specific.

- In over 20-30 personal memoirs not once I've seen this mentioned

- In the above type-specific training video, they explicitly ask about prohibited maneuvers. The reply doesn't mention stall turns. Not even power on spins. The only thing they're worried about is keeping the oil being fed to the engine.

- The real life P-51 manual does say the throttle should be closed immediately upon entering a spin - but as the above tracks show, in DCS it's too late by then.

Would there be any kind of source that would possibly change your minds (no sarcasm meant)? I'm looking everywhere, this is all I can come up with for now.

 

 

[grafspee]

Let'a talk about something more trivial, like take off.

Just set 20-25C which is not super hot anyway, and try to take off, apparently in DCS you have to use 2700rpm and 40" to not over heat because if i use 3000rpm even 50" won't prevent plane to overheat so yes cooling efficiency is below the real one.  P-51 manual states clearly that manual mode for radiator is used only when auto fails if you leave cooling in Auto mode in DCS you just cook engine at take off.

@Reflectedyeah full engine run up was done by crew regular. 

Edited February 16, 2022 by grafspee

[NineLine]

18 minutes ago, Reflected said:

Yes, you can do stall turns at max continuous and closing the throttle to 0 as the speed drops below 100. But that's not a realistic combat scenario. I have yet to hear a convincing argument why this behavior is correct. Above are listed several counter arguments. Pilots' notes, memoirs, anecdotes, training videos, you name it. And the only counter argument I've heard is 'You can't expect to cross the red line without any consequence'.

No, I'm not expecting that. But I do expect being able to stall out and tumble for 4-5 seconds without permanently destroying the engine. Who knows, maybe the the temp took longer to climb and cross the red line? Maybe the prop wash is not factored in DCS? I can't see what's under the hood, I just see the symptom, a behavior that looks unrealistic to me based on the below and above mentioned arguments:

- The Spit MkI's negative g cutout is all over the news, yet a way more dangerous and permanent issue is not? This gave a marked advantage to the 109. I guess not killing the engine in the vertical is a more marked advantage yet never mentioned.

- Both the Spit and the Mustang was regularly ran up to full throttle on the ground (0 airspeed) - see video below as an example. In this track, it took me only 15 seconds at full throttle to cause permanent damage: p51cooling4.trk

- None of the pilots' notes mention this danger, apparently because it's not Merlin specific, but the other warbirds in DCS are not prone to this, because it's Merlin specific.

- In over 20-30 personal memoirs not once I've seen this mentioned

- In the above type-specific training video, they explicitly ask about prohibited maneuvers. The reply doesn't mention stall turns. Not even power on spins. The only thing they're worried about is keeping the oil being fed to the engine.

- The real life P-51 manual does say the throttle should be closed immediately upon entering a spin - but as the above tracks show, in DCS it's too late by then.

Would there be any kind of source that would possibly change your minds (no sarcasm meant)? I'm looking everywhere, this is all I can come up with for now.

 

 

All I have said is backed up by Nick Grey, you simple cannot keep the throttle up, especially at max, and expect the engine to survive, its simple that. 

Again, it is implied in the manual as you can CLEARLY see in your videos and tracks that you are running the temps outside the limits. You are not flying the aircraft right if it is overheating, I'm sorry that is as simple as it is. I know other games do not model this, and you can firewall everything and not have an issues, but it simple isn't realistic, and honestly I cant see many pilots wanting to get into a stall turn as a tactical maneuver anyways, personally I love it when someone does that in front of me, but it seems hardly beneficial to do in most cases. 

Also when they run it up on the ground, do they open all the coolers full open? I think so, if you do that in there air you can carry a little more power and a little more time, but it is still a bad deal to push the engine hard into a stall. I mean a real Spitfire/P-51 Owner/Operator is telling me exactly this, I don't know what else to say... And after all that, I have stated that we have a new cooling system coming for these aircraft, that will be even more true to life, but at the end of the day, engine abuse is engine abuse. 

And also note, you can have the same issue in the Luftwaffe aircraft, I just jumped into the 109 and did a full power stall turn the results were the same...

[grafspee]

7 minutes ago, NineLine said:

Also when they run it up on the ground, do they open all the coolers full open? I think so,

Exactly they do, but in DCS you will still cook engine on the ground at power way below max.

Do cooling shutter can not keep up with temp change yes, take off at auto cooling mode will make your engine overheat. If ED modeled sctuation speed right, then cooling model is not right.

Edited February 16, 2022 by grafspee

[NineLine]

6 minutes ago, grafspee said:

Exactly they do, but in DCS you will still cook engine on the ground at power way below max.

So you want me to report the bug you cant run high MP and RPM on the ground, because in the air I am not seeing an issue.

Notice on the video above all the cowling and such is removed as well right?
I am running right now at 2800 RPM and 40 in and the coolant temp is higher, oil temp is fine, and engine hasnt exploded.

[Reflected]

1 minute ago, NineLine said:

You are not flying the aircraft right if it is overheating, I'm sorry that is as simple as it is. 

Once again, this is NOT what I'm saying. But should it overheat in a mere 5-6 seconds without airflow? I'm not debating the effects of overheating.

1 minute ago, NineLine said:

I mean a real Spitfire/P-51 Owner/Operator is telling me exactly this, I don't know what else to say...

What exactly did he say about the matter? I'm asking because you're giving me statements that I do not disagree with,  so him backing those up won't help me understand the real life behavior.

@grafspee I do not see that either, I always take off at 3000 RPM and 52" with no problem.

[Doughguy]

Zitat

The real life P-51 manual does say the throttle should be closed immediately upon entering a spin - but as the above tracks show, in DCS it's too late by then.

i dont have the manual at hand but i recall power on spins are mentioned in prohibited manouvers.

again theres multiple things to take kn account. the power on spin alone and lack of airspeed and hence temperature rise from a climb.

if you enter a power spin on its own, the manual has the procedure correctly. youve had enough airspeed beforehand, hence reducing throttle upon entering the spin is correct.

if you howerevet are in a steep climb with airspeed already low and then enter a spin... well.. do the math.

again: speed is cooling cooling is life.

Zitat

 

In over 20-30 personal memoirs not once I've seen this mentioned

 

again. i guess the pilots were taught to keep limits. and whod take the flak for breaking an engine because of a silly mistake. theres simply things peope do not talk about. especially memoirs. personal image.

as for the video i cant really watch it atm but with the hood taken off and coolers open i can imagine why it doesnt break...

iirc ive read that on the ground youre supposed to have the coolers open anyway.

as for sources: well come up with something that tells otherwise.

one cant say things arent realistic without being able to back up claims. eventually the merlin manual will give clues if one can dig that up.

i'm rather neutral here.  the flight model might be indeed kinked but people simpl claiming things arent right based on "sim experience" not being a pilot nor flown that very aircraft let alone in anger is a rather poor argument aswell eh?

 

@grafspee

i cant really see say ive ever cooked the engine on take off. 

it was stated by ed that they work on a new cooling system for the warbirds.

however this wont change general characteristics merely give 4 5 6 more seconds at its best. and i bet you a 10er people will crawl out their holes bitching about.

[grafspee]

@Doughguy @Reflected so you clearly don't watch temp gauge then, set ambient temp at 20-25 C put some rockets and try to take off with auto cooling on and watch temp gauge.

And 4 5 6 s more will change a world in P-51 case.

Edited February 16, 2022 by grafspee

[Reflected]

1 minute ago, Doughguy said:

people simpl claiming things arent right based on "sim experience" not being a pilot nor flown that very aircraft let alone in anger is a rather poor argument aswell eh?

Care to point out where I ever mentioned "based on sim experience" or "anger"? I posted real life sources, haven't played another sim in about 3 years, and I'm not angry at all, only interested. Never mind, if you ever put words in my mouth again so that you can use them against me I'll just ignore it.

3 minutes ago, grafspee said:

@Doughguy @Reflected so you clearly don't watch temp gauge then, set ambient temp at 20-25 C put some rockets and try to take off with auto cooling on and watch temp gauge.

Just tried that. 3000 RPM, 52", 25C ambient, at 'liftoff' the coolant temp was on the red line but nothing serious. In 10 seconds it went down below the red line. No damage was done to the engine whatsoever.

[Doughguy]

vor 30 Minuten schrieb Reflected:

I do not see that either, I always take off at 3000 RPM and 52" with no problem.

me neither.  and ive fairly broadly tried different settings on take off.

cooler open/auto/closed etc.

vor 25 Minuten schrieb grafspee:

@Doughguy @Reflected so you clearly don't watch temp gauge then, set ambient temp at 20-25 C put some rockets and try to take off with auto cooling on and watch temp gauge.

And 4 5 6 s more will change a world in P-51 case.

 

i do. temp is usually high on take off especially with loads but regulates itself if you gain speed.

aswell the manual states that one should be cautious with amb temps above 25 °C. 

funny how everyone is experiencing different things on basic things. like people be talking about entirely different aircraft.

 

Edited February 16, 2022 by Doughguy

[Reflected]

29 minutes ago, NineLine said:

And also note, you can have the same issue in the Luftwaffe aircraft, I just jumped into the 109 and did a full power stall turn the results were the same...

I tried that too but couldn't cook the engine. I went straight up at 1.42 ATA, fell back spinning while the nose was still pointing up, no damage whatsoever. I'm sure you can break it, but it can take a helluva lot more than the Merlin: 109cooling.trk

 

[Doughguy]

vor 21 Minuten schrieb Reflected:

Care to point out where I ever mentioned "based on sim experience" or "anger"? I posted real life sources, haven't played another sim in about 3 years, and I'm not angry at all, only interested. Never mind, if you ever put words in my mouth again so that you can use them against me I'll just ignore it.

look all im sayin is you/we dont have the whole picture here. just because you and i read some accounts and played a sim doesnt make us experts.

youve said it yourself that it appears unrealistic to you because youve not read it in any memoirs. 

again, those books wont capture the whole picture. 

no hard feelings here and no anymosities. its a simple thing of facts vs opinions.

Edited February 16, 2022 by Doughguy

[Reflected]

2 minutes ago, Doughguy said:

look all im sayin is you/we dont have the whole picture here. just because you and i read some accounts and played a sim doesnt make us experts. no hard feelings here. 

I agree with you there. That's why I would love to find out how the real thing behaved. If Nick said explicitly: "the engine should degrade and die if you left the power on in a chandelle below 100 mph" I wouldn't dare questioning that.

Edited February 16, 2022 by Reflected

[Doughguy]

vor 2 Minuten schrieb Reflected:

I agree with you there. That's why I would love to find out how the real thing behaved. If Nick said explicitly: "the engine should degrade and die if you left the power on in a chandelle below 100 mph" I wouldn't dare questioning that.

 

there you go i can settle with that and am curious aswell. but just assuming things because they appear in a certain way w/o having the actual knowledge or just relying on warstories and here say simply arent hard facts.

hard facts would either be a clear statement by a pilot or excerpts of manuals of any kind regarding that very matter.

anything else is mere opinions i must say. wether its right or wrong now.

 

[grafspee]

55 minutes ago, Doughguy said:

me neither.  and ive fairly broadly tried different settings on take off.

cooler open/auto/closed etc.

i do. temp is usually high on take off especially with loads but regulates itself if you gain speed.

aswell the manual states that one should be cautious with amb temps above 25 °C. 

funny how everyone is experiencing different things on basic things. like people be talking about entirely different aircraft.

 

 

Can you point me where is this in p51 manual? I mean real manual not DCS manual. In dcs i know that i must be super cacious about temp.

[Doughguy]

vor 2 Minuten schrieb grafspee:

Can you point me where is this in p51 manual? I mean real manual not DCS manual. In dcs i know that i must be super cacious about temp.

i look it up. ive skimmed the manual yesterday eve and iirc it said something about amb temps if my eyes didnt deceive me. but it was more of a side   note really.