Merlin engines stall and negativ G

[Brennus54]

Hi dear crazy airmen,

We all know that early Merlin engines staled when pilot puted some negativ G. CLOD is a Sim and i think we all expect it is as close as possible to reality.

If I remember right, in the CLOD vanilla version Merlin engines were correctly staling with negativ G.

A part of you guys may alrealdy know that a basic tactic to avoid a british fighter which was in the 6 was to dive in a negativ G with the 109.. In that way the poor experienced Saxon pilot who followed this maneuver was stalling his engine, and the experienced one had to roll 180 ° to follow the dive... (and the 109 is faster in a dive, yes)

AND, as you know, Saxon fighters are far more forgiving than German fighter which are more technics to fly and need experienced pilot to be flown efficiently (this point should not produce any debate, pilots and historians are in agreement about that).

SO, its very frustrating to reproduce histocal tactics which worked and see that the dice are loaded. Merlin just cough but never stall in the current 4.312 version.

The question : Do the 5.00 PATCH will fix this in a correct and historical way ?

La bonne journée

[Bonditaria]

You must be flying too well, if you fly worser you will stall that engine more often.

But in all seriousness, go to the bug tracker and read this:

http://tfbt.nuvturais.de/issues/743

Perhaps it covers the issue? Please upvote the bug if you like it!

[Vlerkies]

Well make sure you are sitting down :P cause it may be 'even less' of an issue than it is now if Miss Tilly and her orifice take center stage.

:salute:

[Akula93]

Hi Brennus54

I tought behavior of merlin engines is historical in this game.

I dont see any differance to neg G behavior of engines on Hurricanes or Spitfires models in TF4 and in vanila game.
Just did test and they do same thing in both game versions, i pull nose down, and sound of engine goes off, and RPMs go down, power lost.
After 5-10s i pull up and fuel goes back in engine and RPM go up in both versions of game same, and engine recovers.
So you belive this is not engine stall, like they had historicly, and this is buged?
What you think should happend to engine thats differant then whats in both game versions, engine should stop working totaly and not being able to restart ?

[ATAG_Colander]

:popcorn2:

[9./JG52 Mindle]

[emoji85]

[BOO]

Hi Brennus54

I tought behavior of merlin engines is historical in this game.

I dont see any differance to neg G behavior of engines on Hurricanes or Spitfires models in TF4 and in vanila game.
Just did test and they do same thing in both game versions, i pull nose down, and sound of engine goes off, and RPMs go down, power lost.
After 5-10s i pull up and fuel goes back in engine and RPM go up in both versions of game same, and engine recovers.
So you belive this is not engine stall, like they had historicly, and this is buged?
What you think should happend to engine thats differant then whats in both game versions, engine should stop working totaly and not being able to restart ?

I think Brennus's point is that the effect of the cut out and stall is significantly smaller than would have been experienced at this point in time in and, as a result, the resultant advantage of gain is also smaller. Im only guessing but this does come back to the "real" v gaming aspects of any simulator in terms of a) just how much engine management is modelled, b) d (it being CLOD) is actually working c) the effect this has on the enjoyment of the game for the average person.

As Bondi points out, theres the bugtraker and that is what its used for. But, for the record, and as a Saxon flyer myself, I do understand Brennus's point because the management of the effect (if not the effect itself) isnt as involved and time consuming as i would imagine it might have been in life.


Regards

BOO

[Brennus54]

Ahah,

thx for your quick answers guys,

First, if you are right and the engine don't stall in the vanilla version, my remember must be wrong. Since the TF patchs i don't have a vanilla version anymore.

Second, i didn't check the bug tracker before wrote my post. My english language isn't very well but i don't read in this bug report the same thing that i explain to you.

I read plenty times that these engines can stall when putting a negativ G. Indeed in many french testimony we can read that "le moteur pouvait caler", it means that the engine could totaly stop.. yes. You never read or hear this from veteran or historian ? Do i am mistaking since 15 years ?

thx for your support Boosterdog. :)

the fact is that in many occasion, when a "merlin engine fighter" was in my six, sometimes i put violent negativ G to avoid his bullets, the saxon plane do the same thing each time and it don't affect his position behind me at all.... never. That is why i think it is strange, furthemore, again, i read many times that these engines could shut down when too much negativ G was put.

[Vlerkies]

24:30 Bader explains.

https://www.youtube.com/watch?v=vDzZnCkbxgs
It sounds good in the game, but the long lasting debate has been about the penalty (in airspeed) for just following, despite the sound.

Half rolls takes/buys time, time for the enemy to escape, and also they loose sight of their prey for a moment.

Its been debated on these forums ad nausem though and it is what it is.
Come TF5, i expect the Miss Shilling will make an appearance anyway making this all moot. The carbs pretty much act as if they have the restrictor already.

[Gromit]

Reality is if your already in gun range just sticking your nose down is not going to save you, the guys who dived away in reality did not have an enemy 100yds behind them!

Engine cutout will not affect how the elevators work, a 109 cant expect it's dive manoeuvre to be more effective as that is a function of elevators not engine, a spit or hurri can bunt it's nose just as well as a 109, if your out of gun range the dive acceleration and the resultant neg G cut on the attacker will allow you to extend and escape, BUT, this is TOTALLY dependant on the situation, if the attacker has more energy you will take longer to escape and therefore be vulnerable, the dive away works fine as long as you have not left it too late.

So if your in a close in dogfight it's too late, you cant outrun bullets!

[Brennus54]

The carbs pretty much act as if they have the restrictor already.

I consider this as a confession.

[Brennus54]

Reality is if your already in gun range just sticking your nose down is not going to save you, the guys who dived away in reality did not have an enemy 100yds behind them!

Engine cutout will not affect how the elevators work, a 109 cant expect it's dive manoeuvre to be more effective as that is a function of elevators not engine, a spit or hurri can bunt it's nose just as well as a 109, if your out of gun range the dive acceleration and the resultant neg G cut on the attacker will allow you to extend and escape, BUT, this is TOTALLY dependant on the situation, if the attacker has more energy you will take longer to escape and therefore be vulnerable, the dive away works fine as long as you have not left it too late.

So if your in a close in dogfight it's too late, you cant outrun bullets!

Of course gromit, i agree, but that is not the question here.

[Vlerkies]

I consider this as a confession.
Not for me to make any confession lol. I just know an engine will loose power and drive without fuel, thats all, not just sound.

It's been a point of contention and/or discussion for a long while and we have all just learned to live with it.

Moving forward though to TF5.0, it would arguably be a moot point as in '41 Miss Shilling was doing her rounds around the RAF airfields sorting the starvation issue out, albeit being a interim measure, but certainly much improved.
Anyway, with a bit of patience and teamworkthe mighty Luftwaffe will prevail.
Even in real life the odds were stacked, at least after '41.

:salute:

[Akula93]

I think Brennus's point is that the effect of the cut out and stall is significantly smaller than would have been experienced at this point in time in and, as a result, the resultant advantage of gain is also smaller. Im only guessing but this does come back to the "real" v gaming aspects of any simulator in terms of a) just how much engine management is modelled, b) d (it being CLOD) is actually working c) the effect this has on the enjoyment of the game for the average person.

As Bondi points out, theres the bugtraker and that is what its used for. But, for the record, and as a Saxon flyer myself, I do understand Brennus's point because the management of the effect (if not the effect itself) isnt as involved and time consuming as i would imagine it might have been in life.


Regards

BOO

Thanks now its clear to me, as i see that effect is modeled and not changed from vanila game, he just wonts it to be bigger so advantage is better. ( Hope that means not to also add flying spaners, dust and stuff in cocpits like that guy says in video Vlerkies posted ;) )

[Gromit]

I consider this as a confession.

Guys go fly one, the cutout is there and does what it's supposed to, negative G cutout does not happen instantly with the slightest neg G, the float chamber has fuel in it so the engine runs until that is drained, but just fly one and push the nose down it's splutters and coughs until you restore + G .

[Akula93]

Guys go fly one, the cutout is there and does what it's supposed to, negative G cutout does not happen instantly with the slightest neg G, the float chamber has fuel in it so the engine runs until that is drained, but just fly one and push the nose down it's splutters and coughs until you restore + G .

Yes this is what i see in tests in both games, but no spanners flying in cocpits , good ground crew :)

[Gromit]

Of course gromit, i agree, but that is not the question here.

Then I don't understand , you wrote -

""the fact is that in many occasion, when a "merlin engine fighter" was in my six, sometimes i put violent negativ G to avoid his bullets, the saxon plane do the same thing each time and it don't affect his position behind me at all.... never. That is why i think it is strange, furthemore, again, i read many times that these engines could shut down when too much negativ G was put. ""

if he is shooting at you it's too late, the engine spluttering does not stop the elevators working, so I am confused here?

[Brennus54]

Then I don't understand , you wrote -

""the fact is that in many occasion, when a "merlin engine fighter" was in my six, sometimes i put violent negativ G to avoid his bullets, the saxon plane do the same thing each time and it don't affect his position behind me at all.... never. That is why i think it is strange, furthemore, again, i read many times that these engines could shut down when too much negativ G was put. ""

if he is shooting at you it's too late, the engine spluttering does not stop the elevators working, so I am confused here?

It was a secondary arguement,
the question here is the penalty for negativ G with merlin engines. In the first post i wrote that sometimes the engine should stop when too many negativ G are put.

[Gromit]

It was a secondary arguement,
the question here is the penalty for negativ G with merlin engines. In the first post i wrote that sometimes the engine should stop when too many negativ G are put.

the prop is not feathered and is windmilling rotating the engine, as soon as you restore +G the engine is going to restart, just like bump starting a car with a flat battery, unless of course you let your airspeed drop to critical levels!

The problem is you read these comments such as engine stops and you don't get the full picture, if can you find any tests where they do this and describe what is required to restart the engine then that would clear thing considerably, because we can interpret what is written to suit ourselves, you need facts not anecdotes without specifics.

[Brennus54]

the prop is not feathered and is windmilling rotating the engine, as soon as you restore +G the engine is going to restart, just like bump starting a car with a flat battery, unless of course you let your airspeed drop to critical levels!

The problem is you read these comments such as engine stops and you don't get the full picture, can you find any tests where they do this and describe what is required to restart the engine, because you can interpret what is written to suit ourselves, you need facts not anecdotes without specifics.

I understand Gromit,
The fact is just that this information is very well know here, "caler" mean "shut down" in french. But again, maybe i am mistaken since 15 years;
Really nobody have the same information ?

[Gromit]

I have never found any technical info on this subject I have looked, just anecdotes, one thing I would say to anyone on this matter however, how many rpm does the starter on a merlin use to start the engine?

Because logically if your above this rpm threshold and the magneto's and fuel pump is working I can see no logical reason why the already hot engine would fail to re start under the rotation of the prop

[Vlerkies]

Guys go fly one, the cutout is there and does what it's supposed to, negative G cutout does not happen instantly with the slightest neg G, the float chamber has fuel in it so the engine runs until that is drained, but just fly one and push the nose down it's splutters and coughs until you restore + G .
The bone of contention is not that it is or isnt there, its more about the last bit, does it represent what it is supposed to, in speed and power sacrifice, not just a blurrrrrrr sound,.

It's little to nothing other than a sound splutter issue with little consequence, be honest, when in real life, it was avoided like the plague.

[Gromit]

The bone of contention is not that it is or isnt there, its more about the last bit, does it represent what it is supposed to, in speed and power sacrifice, not just a blurrrrrrr sound,.

It's little to nothing other than a sound splutter issue with little consequence, be honest, when in real life, it was avoided like the plague.

Test it Vlerkies, the engine splutters and the acceleration slows, bear in mind your going downhill so your never going to lose airspeed but your dive acceleration is hampered.

[Vlerkies]

Test it Vlerkies, the engine splutters and the acceleration slows, bear in mind your going downhill so your never going to lose airspeed but your dive acceleration is hampered.

I agree on almost all counts, BUT!
Sry theres a but. :)

You are chasing something that is going at full tilt!
It's only this little bit that irks me.
When you loose power, you properly loose power, and a plane going hell for leather at 2500+ rpm in front of you in a dive is really going to make some ground.

As you well know, there were tactics to combat this by RAF pilots, effective ones.
Still though been chased to many times in a dive away to think it was/is/right.

Anyway, like I sad above, TF5 all over anyway.

[Akula93]

The bone of contention is not that it is or isnt there, its more about the last bit, does it represent what it is supposed to, in speed and power sacrifice, not just a blurrrrrrr sound,.

It's little to nothing other than a sound splutter issue with little consequence, be honest, when in real life, it was avoided like the plague.


Maybe because in real life i would not wont to risk my engine stop running for even few seconds, as its my only safe way home and i for sure would not care if one enemy just run away from me when i have advantage on him and can disangadge and go home while hes in a dive, but in game i dont care if its not running as im safe in my La-Z-Boy. :)

[RAF74_Buzzsaw]

This issue has been discussed many times before.

TF has researched the subject in great detail, and the current modeling is correct.

We do not plan any changes for TF 5.0.