Are engine limitations purely temperature based?

You cant hear or feel anything when engine is running too hot. This is what pilots had to do, monitor engine temps while in a fight.

Once you will hear or see something it will permanent damage to engine.

You wont notice performance deterioration too unless it is big lose in performance which = engine is dead any way.

The whole idea of heaving MP,RPM, oil temp, coolant temp, carb temp is that pilot cant hear smell or see it, he need gauges for it.

And that is exactly why those types of extreme settings are not seen in combat servers, because you simply do not have the time to monitor them as closely as you need to, to "Ride the razors edge" of performance. Though, it IS there if/when you might need it.

Regarding the long term wear issues being implemented. True, would indeed be more realistic, but then would have to expect realistic repair times. Oh, and by the way, that would then lead to realistic health conditions. Get wounded? can fly for X amount of time, if ever again.. I mean you want realism right?

So, back to reality, in that this is just entertainment software, so it is just "easy" that we all get to jump into fresh aircraft with healthy bodies and go out and attack someone else also "at their best".

I'm not going in to this rabbit hole with you.

The risk of overboosting was discussed there as well. Someone metioned a story of a P-38 pilot who flew a sortie with the RPM way lower than recommended for a certain manifold pressure cause he believed it would save fuel. When he landed he still had plenty of fuel leftover whereas the rest of the squadron landed more or less on fumes.

 

The mechanics asked how he did it and when he answered they were furious, believing hed ruined 2 good engines. They tore them apart for inspection and found nothing wrong with them.

 

So apparently its not so simple to figure out exactly what will happen with weird engine settings sometimes.

I think this is a great example of how engines don't just break when running outside of the specs. Having death clocks and other mechanics to kill the engine, mostly instantly in sims I might add, is pure BS. Running certain settings longer than the times given in manuals will sure make the thing last less long in the end, but most probably it won't be noticable on sortie unless it's considerably much over the limits.

For example the Harrier has a limit with TO WI that goes for 15 seconds (short lift wet). If you use this 16 seconds or more, the JPT goes up, literally lowering the operational limits instantly. If you use that for 15 seconds, then fly at 70% RPM and <500°C JPT for half an hour and then start using a power setting that's cleared for 30 minutes, the same happens, because the limit has been "used up" with those 15s at short lift wet. Bollocks! BTW that other sim that shall not be named acts exactly like this as well - at least it's better than its predecessor that had simple death clocks without considering different power settings at all. But this is a great example, as sims have been using those techniques to literally enforce those operational limits for ages, that has been burned into the minds as what it should be, and exactly that's the problem we have to face. Engines don't instantly die IRL unless they run out of oil or take damage from outside sources which is something you really don't want to happen. Of course they're sensitive to overboosting or even underboosting and if you're off too far from the specs you'll not be having a nice day, but still it won't happen from one second to another.

Nick talked about this in the

That would be nice idea, when wear of the engine would be saved somewhere and assigned to IP.

As an option for combat servers. With limited number of aircraft per player.

That would actually be amazing to have your "personal" airframe with all the strain and fatigue added to it over the course as you go fly several missions. To reset it, just repair. If you don't do that, you might take it over to the next mission or get a new one there (= make it an option). Would especially be cool for campaigns. And not just the engine... the whole thing.

The problem, as I see it, is how the engine damage is represented in DCS. The unrealistic CLONK! sound with the propeller seizing. Instant death. Even Nick Grey stated in an interview that it is "rubbish".

Actually I wanted to post that bit as well,

Folks you discuss things noone IRL would really consider when operating the plane.

The P-51D is meant to have the coolant/oil rad doors in AUTOMATIC basically all the time. If the automatic works properly it will open the door fully on the ground. If it doesn't its not working properly and should return to the ramp and not go flying.

About powersettings. I know no sane pilot that would try to fly such a plane at max power setting with a lower RPM than given in the POH. I also never read a single account of a fighter pilot ever reducing RPM when he had to go balls to the wall on an escape.

This is just gamey FlighSimmer Min-Max BS behaviour as most sims simply lack the modelling of the funny consequences of detonation that will very likely appear in a situation where you try to run a V-1650-7 at 61" or 67" inches @ only 2700-2800 RPM.

Engine damage modelling is suffering in most sims, which create articifical limits in engine operations that where not present actual operations of the planes and engines. There are from all sides alot of references where guys just flew balls to the wall until they hit the homeplate without the engine quiting. Was is useable after that torture no, did it outright fail? No. But keep in mind, that to some extend is also survivor bias. Those guys returned and could tell the story. How many never made it back to report on when their engine failed due to overstress at overtime WEP use.

I agree, this is SIM behavior and I have done nothing but explain THAT side of it. I enjoy racing aircraft in DCS. There is a small community that enjoys doing the same. With that, we use what is given to us to the utmost potential, thus, these settings have been discovered YEARS ago. IF ED chooses to change things to more realistic behavior, so be it. In the meantime, this is, what it is.

Still, will also say this, the manuals are written for what is safe and PROVEN. I am sure there are plenty of pilots, ESPECIALLY in a wartime condition, threw the book out the window and did what they thought they need to to survive. Sometimes it works, sometimes it gets them killed. There are manual modes for a reason for cooling, if something could be pushed a bit further, that is the pilot's choice.

The P-51D is meant to have the coolant/oil rad doors in AUTOMATIC basically all the time. If the automatic works properly it will open the door fully on the ground. If it doesn't its not working properly and should return to the ramp and not go flying.

You are of course correct. Unfortunately this belief in using the manual setting to fully OPEN comes from the DCS P-51 Manual on page 126 but it does clearly state that it should be in AUTOMATIC for takeoff, it also says that it should be in full OPEN for all operation on the ground.

The real manual states that the pilot should OPEN and CLOSE the Coolant and Oil switches manually and listen to determine if the doors are opening during the pre-start procedures. Then set to AUTOMATIC. It never talks about opening them again during normal procedures. The next step is to prime the engine and starting. It doesn't mention anything about opening these for taxing and checking that they are set to AUTOMATIC is the first item on the pre-takeoff checklist.

This is one of my favorite subjects in DCS.

It's clear that many people don't understand the workings of IC engines and how manifold pressure works and/or is generated and how actual requested power vs. maximum power (potential) relates to throttle settings (which we don't have control of BTW...) and how that mixes with prop pitch.

I'm not saying DCS gets all of this perfect and that there's no "gaming" of the simulation going on :). Just for the record :).

The P-51D is meant to have the coolant/oil rad doors in AUTOMATIC basically all the time. If the automatic works properly it will open the door fully on the ground. If it doesn't its not working properly and should return to the ramp and not go flying.

It doesn't work this way though.

The door moves too slow. I don't know if it moves at a realistic speed or not but when you taxi it has some level of airflow and "auto" closes the door a decent bit from full open. It sits there and maintains and indeed works just fine....

Until you get on the power :).

The heat ramps up quite quickly and the door doesn't keep up.

Makes much more sense to do it like the manual states. Open it, then put it in auto sometime after going full power. Or just before or whatever...

The real manual states that the pilot should OPEN and CLOSE the Coolant and Oil switches manually and listen to determine if the doors are opening during the pre-start procedures.

Excalty. You check that the doors will react on the pre start CL. Than put them in AUTO and leave them there and monitor the temps to see if they work properly.

The heat ramps up quite quickly and the door doesn't keep up.

Not sure how you operate it on the ground. I operate it like the real one and it does just fine. Take care to have atleast around 1000rpm all the time, no tail wind and the temps with AUTO working will just stay in the allowed temps range. If coolant ramps up due to outside conditions and you have to wait anywhere, turn into the wind, increase RPM to about 1500 and temp will stay within limits.

I never ever had a situation so far in DCS where the AUTOMATIC wasn't able to handle ground operations from start up over take-off to climb out.

If auto cant keep temps within limits manual will also fail, cause the max open position is the same for both and the coolant capability is the same.

Folks you discuss things noone IRL would really consider when operating the plane.

 

The P-51D is meant to have the coolant/oil rad doors in AUTOMATIC basically all the time. If the automatic works properly it will open the door fully on the ground. If it doesn't its not working properly and should return to the ramp and not go flying.

 

 

About powersettings. I know no sane pilot that would try to fly such a plane at max power setting with a lower RPM than given in the POH. I also never read a single account of a fighter pilot ever reducing RPM when he had to go balls to the wall on an escape.

 

This is just gamey FlighSimmer Min-Max BS behaviour as most sims simply lack the modelling of the funny consequences of detonation that will very likely appear in a situation where you try to run a V-1650-7 at 61" or 67" inches @ only 2700-2800 RPM.

 

 

Engine damage modelling is suffering in most sims, which create articifical limits in engine operations that where not present actual operations of the planes and engines. There are from all sides alot of references where guys just flew balls to the wall until they hit the homeplate without the engine quiting. Was is useable after that torture no, did it outright fail? No. But keep in mind, that to some extend is also survivor bias. Those guys returned and could tell the story. How many never made it back to report on when their engine failed due to overstress at overtime WEP use.

Amen to this.

Getting higher speed at low rpm it is purely theoretical BS nothing common with real plane. As you said.

And radiators doors were set up for best speed, you start manual operating them you get less performance.

In DCS more you close coolnat radiators more speed you gain, those tests says something difrent.

Are you aware that you can also manually manipulate the radiator flaps on both the 109 and 190 for increased speed as well? With the same consequences of overheat and engine failure.

If the pilot, has within his controls, the ability to manually manipulate them, expect them to be. I expect ED to have all of this information and this is what they have given us. At this point it has to be proven otherwise. Yes some charts have been shown and reasonable deductions made as to what would happen for this or that. Again, I expect ED has seen this data and made their choices as to how they want it to be. If they finally decide to change it, based on accurate information, so be it, but until then, it is what it is, a piece of entertainment software that you paid minimal money for, not a reality simulator.

Are you aware that you can also manually manipulate the radiator flaps on both the 109 and 190 for increased speed as well? With the same consequences of overheat and engine failure.

 

If the pilot, has within his controls, the ability to manually manipulate them, expect them to be. I expect ED to have all of this information and this is what they have given us. At this point it has to be proven otherwise. Yes some charts have been shown and reasonable deductions made as to what would happen for this or that. Again, I expect ED has seen this data and made their choices as to how they want it to be. If they finally decide to change it, based on accurate information, so be it, but until then, it is what it is, a piece of entertainment software that you paid minimal money for, not a reality simulator.

Can't you see that, you loose speed in p-51, according to this graph best speed should be obtained at 95C coolant temp.

So when you close coolant doors too much you loose speed not gain.In DCS you gain speed but no idea why.

If it comes to Oil shutter yes when close completely you have more speed, but not coolant, Fully closed coolant gives as much speed as fully open.

Coolant doors aren't simulated correctly here, it is clear.

Amazingme was right, if you shut those doors completely cross section is changing rapidly in this point creating additional drag, even when Meredith effect is strongest there, is handicapped by this drag.

So good balance must be obtained then between drag and Meredith effect, so manually closing or opening those doors should not give any speed if set up properly, Basically Green arc in temp gauge is the best setup for speed,

At least for continuous power. 46"/2700rpm, At this rating DCS p-51 act different. then on this graph above.

I see the chart, and agree that DCS does not follow that curve. What I am saying is that ED makes the decision as to why it is the way it is. I am just using what is provided to me.

Realism simulation, as you pointed out, is a VERY deep rabbit hole. ED is the one making the decisions on what is economically viable for how far down that rabbit hole they want to go down. We can make requests, or point out facts. They still have to implement it if they deem it worthy and the accuracy that THEY are going after.

So, on the point of realism, having a mission (scaled down for playable numbers) of say only 4 109k4, maybe 8 190's versus 30 Mustangs and say 100 bombers would be playable? Many that scream for realism would balk at the unbalance. Yet at that time of the war. Those are equivalent ratios the Germans had to deal with when those aircraft were available.

The point I am trying to make is enjoy what you are given, report with what you dont agree with and hope, but dont expect, that things will get implemented. If you do not enjoy it, there are plenty of other things out there to experience.

I see the chart, and agree that DCS does not follow that curve. What I am saying is that ED makes the decision as to why it is the way it is. I am just using what is provided to me.

 

Realism simulation, as you pointed out, is a VERY deep rabbit hole. ED is the one making the decisions on what is economically viable for how far down that rabbit hole they want to go down. We can make requests, or point out facts. They still have to implement it if they deem it worthy and the accuracy that THEY are going after.

 

So, on the point of realism, having a mission (scaled down for playable numbers) of say only 4 109k4, maybe 8 190's versus 30 Mustangs and say 100 bombers would be playable? Many that scream for realism would balk at the unbalance. Yet at that time of the war. Those are equivalent ratios the Germans had to deal with when those aircraft were available.

 

The point I am trying to make is enjoy what you are given, report with what you dont agree with and hope, but dont expect, that things will get implemented. If you do not enjoy it, there are plenty of other things out there to experience.

Partially agree, but for me DCS is Sim first, so lets get this sim right then we can start worry about historical balance,

In DCS defense, probably all planes are affected by this error, so p-51 isn't really much ahead based on this error, but because it was damm fast plane :)

I ran the engine pretty hard chasing down a K4, it never red lined. After killing him I brought it right back to 24 and 35 and rtb'd. 1 mile short of the rwy the engine seized. Is this normal?

I ran the engine pretty hard chasing down a K4, it never red lined. After killing him I brought it right back to 24 and 35 and rtb'd. 1 mile short of the rwy the engine seized. Is this normal?

Yes, common engine seizure due to WEP use.

In my opinion, not need to be changed, it is excellent