correct as-is Cannot do a hammerhead without breaking engine

[andremsmv]

I have found that after the most recent update, it is impossible to do any sort of aggressive climbing maneuver in the P-51 without immediately leaking coolant and losing significant engine power. I'm not exactly sure what is causing this but this was not always the case and it is extremely difficult to effectively fly the P-51 in combat wit this bug now.

can't do a hammerhead.trk

[=475FG= Dawger]

-1 G for more than 10 seconds is a bad idea.

 

[grafspee]

ED implemented overheat damage to the engine, before you could hit 150c and you got some minor engine damage right now if you get to this temp your engine dies quick, and the symptom of damage is small vapor trail.

Edited July 13, 2021 by grafspee

[andremsmv]

14 hours ago, pmiceli said:

-1 G for more than 10 seconds is a bad idea.

 

 

This is a good point, but I just tested this without pulling any negative G's and my engine still broke.

 

Edit: I also decided to test actual -1G's for more than 10 seconds, and as expected the fuel pressure dropped to zero and the engine lost power (and for some reason the RPM shot to 4,000 and if someone can explain to me why this happens I would much appreciate this). I rolled back to level flight and my engine gauges returned perfectly to normal and there was no engine damage whatsoever, so this is not what causes the engine damage in an Immelmann or high-pitch maneuver.

Edited July 13, 2021 by andremsmv

[grafspee]

RPM shot to 4000 because, when engine loses power, prop governor cranks to prop fine pitch in order to maintain set rpm, so when engine got back fuel, sudden surge of power increased engine rpm so fast that prop governor could not react in time, it takes couple of seconds to blade pitch adapt to new situation, this is the reason why manuals advice not to do any sudden moves with throttle.

[grafspee]

22 hours ago, andremsmv said:

I have found that after the most recent update, it is impossible to do any sort of aggressive climbing maneuver in the P-51 without immediately leaking coolant and losing significant engine power. 

Coolant and engine overheat is the reason why you lost power. Trailing white vapor is indication of this.

[_Spad_]

On 7/13/2021 at 6:41 AM, andremsmv said:

I have found that after the most recent update, it is impossible to do any sort of aggressive climbing maneuver in the P-51 without immediately leaking coolant and losing significant engine power. I'm not exactly sure what is causing this but this was not always the case and it is extremely difficult to effectively fly the P-51 in combat wit this bug now.

can't do a hammerhead.trk 2.48 MB · 4 downloads

I haven't watched the track but the engine might have already been hot before you went into a climb? The reduced airflow at the top of the climb may have been enough to cook it.

[andremsmv]

On 7/13/2021 at 5:08 PM, _Spad_ said:

I haven't watched the track but the engine might have already been hot before you went into a climb? The reduced airflow at the top of the climb may have been enough to cook it.

That is a good point!

 

I did ensure that all the temperature gauges were in the green before I commenced my maneuver (as would be verified by the track file). It's a very short track file, and very easy to replicate. In fact, I have not been able to point my nose straight up and keep it there for more than 5 seconds without my engine dying. This does not happen with any other warbird.

[grafspee]

1 hour ago, andremsmv said:

That is a good point!

 

I did ensure that all the temperature gauges were in the green before I commenced my maneuver (as would be verified by the track file). It's a very short track file, and very easy to replicate. In fact, I have not been able to point my nose straight up and keep it there for more than 5 seconds without my engine dying. This does not happen with any other warbird.

I watched it, you overheated the engine. You went above 150c in quick time. In after mission raport it says Engine overheated   

It was always like this, but damage done to the engine until recent was very small, so you could continue flight, now you blow the cooling system venting coolant and engine it self getting fatal damage as well.

Edited July 15, 2021 by grafspee

[andremsmv]

On 7/14/2021 at 11:52 PM, grafspee said:

I watched it, you overheated the engine. You went above 150c in quick time. In after mission raport it says Engine overheated   

It was always like this, but damage done to the engine until recent was very small, so you could continue flight, now you blow the cooling system venting coolant and engine it self getting fatal damage as well.

 

Yes that is my point! That the engine overheats far too quickly. Note that I did start the maneuver at a normal engine temperature.

[grafspee]

Since i own dcs p-51, it stragle to cool down below 200mph when ambient temp is above 20c. Only what changed recently is new engine behavior when overheating. Prior to that you could hit 150c and plane kept flying.

If it comes to real P-51 i doubd that it is possible to do such thing 61" 3000 and hand on the prop 0 airspeed, you would blow motor as well.

Edited July 18, 2021 by grafspee

[Magic Zach]

As a guy that does shenanigans on the Aerobatics Online server quite often, I can say that you can do a hammerhead in the 51, but it's a lot better if you do it to the left, and you can't have the engine firewalled constantly at the top, below 150 indicated.
Zoom up straight vertical
Monitor your angle
At 175 IAS, chop the throttle, apply a little right rudder
Once you fall under 100, smash the throttle forwards and kick the rudder left
When you swing until your nose is at the horizon roughly, cut the throttle but keep holding left rudder
Fall
When pointing down, ease throttle back up but watch the temps, they can be a bit toasty after that but can be cooled down pretty quickly again as well

Edited July 18, 2021 by Magic Zach

[NineLine]

On 7/18/2021 at 8:47 AM, andremsmv said:

Yes that is my point! That the engine overheats far too quickly. Note that I did start the maneuver at a normal engine temperature.

I am not sure I would agree that it overheated far to quickly, you kept the engine pretty much full open the whole time, the Mustang needs airflow, when you take it to stall but dont pull back on the throttle, you are going to overheat really fast, and you never gave it a chance to catch its breath. You need to manage the power as you slow down, keeping it full open at slow speeds and you get what you got.

[NineLine]

@Yo-Yoour FM dev was inspired to do a hammerhead after this thread showed up. 
 

 

[=475FG= Dawger]

On 7/28/2021 at 3:22 PM, NineLine said:

I am not sure I would agree that it overheated far to quickly, you kept the engine pretty much full open the whole time, the Mustang needs airflow, when you take it to stall but dont pull back on the throttle, you are going to overheat really fast, and you never gave it a chance to catch its breath. You need to manage the power as you slow down, keeping it full open at slow speeds and you get what you got.

So, why doesn't this same failure occur in the other water cooled aircraft in game if it is airflow related?

[NineLine]

Yes, it depends on the aircraft for sure, the Spitfire will overheat as well just like this. Some of the radials are much tougher engines, etc.

[grafspee]

This bother me as well for example, P-47 at stationary, cooling is provided by prop's internal part of blades which are not too sufficient, in case of P-51 or spitfire, outer parts of blades produce  prop wash for radiators , which imho should be greater  then inner parts in case of P-47. As i saw prop thrust diagram at about 3/4 length from prop center peak thrust is produced, this is where are P-51's or spitfire's coolers are.   

P-47 no problem, but in case of P-51 at warm day, i can't use full power for take off, coolant temp climbing up even at 200mph.

Edited July 29, 2021 by grafspee

[=475FG= Dawger]

39 minutes ago, NineLine said:

Yes, it depends on the aircraft for sure, the Spitfire will overheat as well just like this. Some of the radials are much tougher engines, etc.

Radials in DCS are all air-cooled so the P-47 and Fw190A8 are excluded from this conversation. 
 

However, if there is a failure mode in the P-51 due to insufficient airflow through the radiator at high power settings, one would expect to be able to achieve similar failures in the Spitfire, Dora and 109. 
 

I have not specifically tested the Dora or Spitfire but the 109 certainly does not fail in this manner.

 

So, why not? 
 

Either it is incorrect in the 109 or incorrect on the P-51.

 

Please let me know which so that I may submit the report appropriately. 

[NineLine]

You probably need to try to abuse them like you were abusing the Mustang and you will find your answer:

 

32 minutes ago, grafspee said:

This bother me as well for example, P-47 at stationary, cooling is provided by prop's internal part of blades which are not too sufficient, in case of P-51 or spitfire, outer parts of blades produce  prop wash for radiators , which imho should be greater  then inner parts in case of P-47. As i saw prop thrust diagram at about 3/4 length from prop center peak thrust is produced, this is where are P-51's or spitfire's coolers are.   

P-47 no problem, but in case of P-51 at warm day, i can't use full power for take off, coolant temp climbing up even at 200mph.

 

Cooling system is not perfect in the water cooled birds, as far as I am to understand it, the dev team still needs to update the cooling system to the new cooling system we introduced with the P-47/190A. That said, they are all different aircraft and will act differently based on their systems, one shoe doesnt fit all.

[=475FG= Dawger]

16 minutes ago, NineLine said:

You probably need to try to abuse them like you were abusing the Mustang and you will find your answer:

 

That wasn’t me but I will be putting together a comparison set of videos and tracks with regard to this issue.

 

There is a definite disparity in behavior. Yes, you can blow the 109 engine if you exceed its operating limits but the P-51 engine will fail when operated within its limits and the reasoning presented is lack of radiator airflow. If this is the case, it should similarly affect all liquid cooled engines.

16 minutes ago, NineLine said:

 

[NineLine]

6 minutes ago, pmiceli said:

There is a definite disparity in behavior. Yes, you can blow the 109 engine if you exceed its operating limits but the P-51 engine will fail when operated within its limits and the reasoning presented is lack of radiator airflow. If this is the case, it should similarly affect all liquid cooled engines.

Yes, please feel free to show me it operating it within its limits and it blowing, I would be happy to see the tracks. Thanks.

[Yo-Yo]

51 minutes ago, grafspee said:

This bother me as well for example, P-47 at stationary, cooling is provided by prop's internal part of blades which are not too sufficient, in case of P-51 or spitfire, outer parts of blades produce  prop wash for radiators , which imho should be greater  then inner parts in case of P-47. As i saw prop thrust diagram at about 3/4 length from prop center peak thrust is produced, this is where are P-51's or spitfire's coolers are.   

P-47 no problem, but in case of P-51 at warm day, i can't use full power for take off, coolant temp climbing up even at 200mph.

 

The amount of heat the system can dissipate depends not only on the air flow through it but on the temperature difference. For air cooled engines it much greater.

[=475FG= Dawger]

38 minutes ago, NineLine said:

Yes, please feel free to show me it operating it within its limits and it blowing, I would be happy to see the tracks. Thanks.

PM sent

[grafspee]

8 hours ago, Yo-Yo said:

The amount of heat the system can dissipate depends not only on the air flow through it but on the temperature difference. For air cooled engines it much greater.

Idea for liquid cooling is, that with cooling radiator you can achieve much much greater cooling surface then any air cooled engine. By the look of P-51 diagram radiator looks pretty large, bigger then 109 both combined, still bf-109 handle temps much better. 

P-51 is capable of doing military power run up on the ground, which is impossible in DCS.

At warm day even with radiator doors w/o 61" take off is not an option, In manuals no a single word about this issue, quite opposite in cold weather additional shutters are installed to prevent over cooling.

Manual states, that radiator controls stays at AUTO position all the time from start up to shut down, manual is used when auto fails, in DCS i have to use manual very often, this definitely says something.

Edited July 30, 2021 by grafspee

[NineLine]

1 hour ago, grafspee said:

Idea for liquid cooling is, that with cooling radiator you can achieve much much greater cooling surface then any air cooled engine. By the look of P-51 diagram radiator looks pretty large, bigger then 109 both combined, still bf-109 handle temps much better. 

P-51 is capable of doing military power run up on the ground, which is impossible in DCS.

At warm day even with radiator doors w/o 61" take off is not an option, In manuals no a single word about this issue, quite opposite in cold weather additional shutters are installed to prevent over cooling.

Manual states, that radiator controls stays at AUTO position all the time from start up to shut down, manual is used when auto fails, in DCS i have to use manual very often, this definitely says something.

 

As stated, there is a new cooling system coming for the liquid cooled engines, that said, abuse is abuse. And for the reference of the OP, it was pure abuse. Thanks.