BF109 Engine Damage in boost/emergency mode

[ZachariasX]

You are missing the point.

 

Unless your point was NOT that engines have actual power limits higher than the stated limits in the manual, then I didn‘t miss the point. It‘s just that if you wanted to disqualify your statements, you did well with what you actually wrote there as last comment. Still I‘m positive you didn‘t exactly mean what your sentence really read.

 

Regarding the limits: Naturally stated engine limits are compelled to be lower than what they could be for a *specific* engine, as they have to be safe limits for *all* engines produced and guarateed under all circumstances.

 

That some Joe could get higher MAP without instantly dying is just a consequence. But since he just flew around maxing what he had at hand, his conclusion are bad advise for someone having in any direction 2 hours of sea underneath him. He said he could abuse the engine for days and be ok. Would you really bet your life on an ex post finding of someone that actually admitted blowing parts of his engine after a couple of days? But yes, since you, unlike in reality, are getting a factory fresh aircraft on every spawn, you don‘t think that this is bad. In real life, since you for sure are good enogh for promotion and a personal aircraft, would you really be flying one that on the next mission you cannot be sure about if the engine lasts the whole mission? Or would you expect you ground crew to exchange powerplants after each landing to put in an engine that they guarantee lastting a whole mission? Or would you be ok them handing you an aircraft that they have no idea whether it will last for a whole mission?

 

How much headroom there is beyond recommended max ratings for each type of engines clearly is another matter.

 

As you stated with your quotes above, American engines do have rather conservative ratings. Depending on athomosphere, there is no predetonation in the Allison (as we have it in the P-40), and you should be able to run it (with good fuels) with the throttle firewalled, *provided you can handle heat*. The Lightning is a slightly different matter, as the turbocharged engine is a much more complicated matter, and running that at sea level at 60‘‘ manifold is very different from running it at 24k feet altitude at this setting. Different partsate getting worn out there as well. High up, you will most likely be restricted by turbo charger bearing temps. You can argue then again, how much margin they have.

 

Generally, the closer you set max limits to the hard limits of the engine, the more frequent engine failures will be over enemy teritory. These losses stand against losses occuring to enemy action due to the pilot having less power at hand. Find your sweet spot.

 

It is clear that given their predicament in 1944 and onwards, the Germans had a different optimum than the Americans.

 

Also, and this is not just semantics, if a pilot says he won‘t do certain setting with the engine „because it wreck the engine“, it does mean that the engine will then be such that it doesn‘t turn the prop no more. You might not like it, but that is what he says.

 

The DB605, besides giving it more displacement to make up for fuel restrictions, is also redesigned for production efficiency. The more conservative use of ball bearings shows that. So if there was an engine that you can kill in a single sortie, personally, a DB605 with Methanol injection I would rank on top of that list. You are welcome to think otherwise though. Test bench runs are not combat situations.

 

As we are having a game here rather than actual war and we don‘t care about bailing out over forests or lakes, as JtD says, we behave slightly different piloting in the game than actual pilots back then would.

 

 

This is why I think one should link „the timer“ to heat from the engine. For the most part, this would be correct as well. Plus you have a gauge showing you the state of „the timer“ plus you know what to do to reset „the timer“ and it would involve having to disengage in many situations, meaning it would be a limit hard enough for people to respect it. What is never accepted in a competitive game is a random, terminal punishment.

 

The alternative would be total systems simulation. Is there anyone here seriously assuming we would get such and keeing the price of the planes the same? A2A simulations does all that, also persistent damage. But their modules are 5x the price.

[Sgt_Joch]

Again again again. 

 

How many time do I have to say this?

 

You keep spewing on about the hard limits, but we are not talking about those. Of course engines eventually hit power they cant handle, and likely fail immediately. WEP is not that. WEP is a setting that is within the hard limits but stresses the parts harder. It does not cause the engine to fail in 5min. You are confusing abusive behavior with catastrophic behavior. And you keep hammering on it like the definitions are going to change all of a sudden.

 

The only thing your quote shows is that you don't understand how WEP works. You push an engine enough, excessive heat and/or over-pressure and/or air-fuel detonation will destroy the engines within minutes.

 

again you are still arguing that the earth is flat when we all know it is round.

 

what we have in the game will not change in principle since it is realistic, you push past a certain point and the engine will eventually fail, whether in the case of a 109F4, it should be 1 minutes, 3?, 5? or some random factor based on time x and temperature Y is what has to be determined.

 

get with the program.

[Corsair]

RNG is bad for games. Its dumb to have things fail at random, especially when the change of it doing so IRL is extremely low. It would be completely asinine to get into a dogfight and suddenly have your engine fail or wing fall off.

But I'm not talking about failing everything randomly (like random structural failures.. that's pointless), but random failures of material (i.e engines) that have been pushed beyond their limits... and randomness doesn't imply high probability as you may suggest..

 

I think I don't understand your point and your don't understand mine.. so I'd like to know, what is your current views on the timed blowup of the engine after exceeding 1 minute of emergency power on the 109? (FYI the blowup always occurs around after 2'30" of emergency power)

Edited January 3, 2018 by EC5/25_Corsair

[LColony_Kong]

Unless your point was NOT that engines have actual power limits higher than the stated limits in the manual, then I didn‘t miss the point. It‘s just that if you wanted to disqualify your statements, you did well with what you actually wrote there as last comment. Still I‘m positive you didn‘t exactly mean what your sentence really read.

 

Regarding the limits: Naturally stated engine limits are compelled to be lower than what they could be for a *specific* engine, as they have to be safe limits for *all* engines produced and guarateed under all circumstances.

 

That some Joe could get higher MAP without instantly dying is just a consequence. But since he just flew around maxing what he had at hand, his conclusion are bad advise for someone having in any direction 2 hours of sea underneath him. He said he could abuse the engine for days and be ok. Would you really bet your life on an ex post finding of someone that actually admitted blowing parts of his engine after a couple of days? But yes, since you, unlike in reality, are getting a factory fresh aircraft on every spawn, you don‘t think that this is bad. In real life, since you for sure are good enogh for promotion and a personal aircraft, would you really be flying one that on the next mission you cannot be sure about if the engine lasts the whole mission? Or would you expect you ground crew to exchange powerplants after each landing to put in an engine that they guarantee lastting a whole mission? Or would you be ok them handing you an aircraft that they have no idea whether it will last for a whole mission?

 

How much headroom there is beyond recommended max ratings for each type of engines clearly is another matter.

 

As you stated with your quotes above, American engines do have rather conservative ratings. Depending on athomosphere, there is no predetonation in the Allison (as we have it in the P-40), and you should be able to run it (with good fuels) with the throttle firewalled, *provided you can handle heat*. The Lightning is a slightly different matter, as the turbocharged engine is a much more complicated matter, and running that at sea level at 60‘‘ manifold is very different from running it at 24k feet altitude at this setting. Different partsate getting worn out there as well. High up, you will most likely be restricted by turbo charger bearing temps. You can argue then again, how much margin they have.

 

Generally, the closer you set max limits to the hard limits of the engine, the more frequent engine failures will be over enemy teritory. These losses stand against losses occuring to enemy action due to the pilot having less power at hand. Find your sweet spot.

 

It is clear that given their predicament in 1944 and onwards, the Germans had a different optimum than the Americans.

 

Also, and this is not just semantics, if a pilot says he won‘t do certain setting with the engine „because it wreck the engine“, it does mean that the engine will then be such that it doesn‘t turn the prop no more. You might not like it, but that is what he says.

 

The DB605, besides giving it more displacement to make up for fuel restrictions, is also redesigned for production efficiency. The more conservative use of ball bearings shows that. So if there was an engine that you can kill in a single sortie, personally, a DB605 with Methanol injection I would rank on top of that list. You are welcome to think otherwise though. Test bench runs are not combat situations.

 

As we are having a game here rather than actual war and we don‘t care about bailing out over forests or lakes, as JtD says, we behave slightly different piloting in the game than actual pilots back then would.

 

 

This is why I think one should link „the timer“ to heat from the engine. For the most part, this would be correct as well. Plus you have a gauge showing you the state of „the timer“ plus you know what to do to reset „the timer“ and it would involve having to disengage in many situations, meaning it would be a limit hard enough for people to respect it. What is never accepted in a competitive game is a random, terminal punishment.

 

The alternative would be total systems simulation. Is there anyone here seriously assuming we would get such and keeing the price of the planes the same? A2A simulations does all that, also persistent damage. But their modules are 5x the price.

The point was you cant make a precise technical statement in the negative from someone whose precise experience is both dubious and clearly not remembered all that accurately. 

 

 

Everything you stated here is just ammunition for my point of view, not yours. You are admitting to the fact that the ratings are dependent on the specific needs of the user nation. You are admitting that the ratings are generally well below actual immediate failure points.  And you are admitting that pilot behavior varies IRL and is also not relevant to how be behave in game. 

 

Which is why it boggles the mind that you still want to implement mechanics that are asinine abstractions that will do a very poor job of "simulating" something we cant really do in a game, while obliterating the practical accuracy of aircraft performance in combat. 

[Sgt_Joch]

 

What this article shows, in actual fact, is that the WEP ratings were absolutely at levels thought possible for use. 60-70 MAP  would not have been allowed if it caused imminent engine seizure: This would have been pointless to allow if it had. Did it make it more likely that some part might fail? Sure. But then again, your air frame has a higher chance of failure at the max G-limit of the air frame. Now and again, you might have a plane that fails when it pulls its rated limit. Crap happens. But that does not mean we should look at proscribed limits as certain failure points. 

 

 

well again you are making the standard rookie mistake of thinking that just because late war, i.e. 44-45 P38s, could handle 60-70" HG, that early war limits don't matter and it was just a matter of pushing the throttle forward.

 

late war planes, whether Allied or Germans used all sorts of improvements, i.e. stronger internal parts, higher octane fuel or anti-detonation like MW50, water injection, intercoolers, etc. so they could handle the higher effective compression ratio without destroying the engine by excessive heat and/or air-fuel pre-detonation and/or mechanical failure. 

 

you push a 109F4 to 1.80 ATA and its life could be measured in seconds.

[LColony_Kong]

The only thing your quote shows is that you don't understand how WEP works. You push an engine enough, excessive heat and/or over-pressure and/or air-fuel detonation will destroy the engines within minutes.

 

again you are still arguing that the earth is flat when we all know it is round.

 

what we have in the game will not change in principle since it is realistic, you push past a certain point and the engine will eventually fail, whether in the case of a 109F4, it should be 1 minutes, 3?, 5? or some random factor based on time x and temperature Y is what has to be determined.

 

get with the program.

No it wont. Sorry, there is no debate on this subject. Engines simply do not fail as a function of time (within minutes) of using WEP. It does not happen. It is not reality. I have already posted ample evidence of this, but you insist on making up this fantasy anyhow. Time based failure happens withing hours. 

 

Learn to live in real life. Not a video game. 

[LColony_Kong]

well again you are making the standard rookie mistake of thinking that just because late war, i.e. 44-45 P38s, could handle 60-70" HG, that early war limits don't matter and it was just a matter of pushing the throttle forward.

 

late war planes, whether Allied or Germans used all sorts of improvements, i.e. stronger internal parts, higher octane fuel or anti-detonation like MW50, water injection, intercoolers, etc. so they could handle the higher effective compression ratio without destroying the engine by excessive heat and/or air-fuel pre-detonation and/or mechanical failure. 

 

you push a 109F4 to 1.80 ATA and its life could be measured in seconds.

[Edited]

 

Enough of that.

 

60-70 MAP was possible on earlier P-38s as well, it just was not an official rating. That quote could be for either. Nor am I arguing that we use power settings that were unofficial or over the instant limits. 

 

And yeah, if you push a F4 to 1.8ata it would fail in seconds. But that is because 1.8ata exceeds the HARD LIMITS of the engine, AND IS NOT, an example of running the engine for a long period at A HIGH BUT PHYSICALLY POSSIBLE POWER. To use the GPU analogy again: Running a higher than default voltage will kill your card quicker, but usually over a long and useful period of time. But you CAN ABSOLUTELY input a voltage that kills it immediately. Just like being rough on the human body causes failure over long periods, not usually immediately. And breaking a bone with a hammer is an example of immediate or rapid failure from a force that is beyond any sort of physical capacity. 

 

-A Bridge will fail after years of use. If you drive a battleship over it it breaks immediately. 

 

For some reason you dont understand the difference between failure due to wear and failure due to hard limit violation. 

Edited January 24, 2018 by Fumes

[ZachariasX]

The point was you cant make a precise technical statement in the negative from someone whose precise experience is both dubious and clearly not remembered all that accurately. 

 

 

Everything you stated here is just ammunition for my point of view, not yours. You are admitting to the fact that the ratings are dependent on the specific needs of the user nation. You are admitting that the ratings are generally well below actual immediate failure points.  And you are admitting that pilot behavior varies IRL and is also not relevant to how be behave in game. 

 

Which is why it boggles the mind that you still want to implement mechanics that are asinine abstractions that will do a very poor job of "simulating" something we cant really do in a game, while obliterating the practical accuracy of aircraft performance in combat.

 

There‘s no need for you being that defensive. Indeed, there is not much of an argument that physical limits of (fresh) engines are higher than ratings in the manual.

 

But I do think you are getting ahed of yourself by disqualifying the opinion of people that one can freely assume knows better than any of us, regardless of his courses in school.

 

Your request for a modelling limits of engines „as they truly are“ I find far from practical (especially as you give no details about how to actually implement it), especially if planes should meet the $10 bracket and be profitable. My argument is now how to best approximate what you are dreaming of. And I consider it far from asinine from using temperature as a mean. High powered engines are for the most part temperature restricted and you will produce a lot of steam by just keeping at max. power and happily do what you are doing.

 

The more you max out an engine, the less margin you have. Try to go 10 km at max power with an F1 car. It will blow up half way. It never has to do more than 2 km full power without a cooling period. That is how narrow you can set a window.

 

On most cases, you will overheat your engine in planes like we have them in the game by using exessive power. Keep in mind, optimal cooling is dimensioned to given rated power outputs. You use more power, up goes your heat. Opening rads is adding drag, so you need to open rads further, leading you in a dumb situation. People can learn how to deal with that in the game and they have in real aircraft.

 

Calling that asinine, fine. But what do you call a wish that is not substancuated with a practical way to realize it? Or should we just be fine in having all engines be allowed throttle fully forward, all the time? Can you be more specific how to fix the issue other than people being incompetent or donkeys?

[LColony_Kong]

There‘s no need for you being that defensive. Indeed, there is not much of an argument that physical limits of (fresh) engines are higher than ratings in the manual.

 

But I do think you are getting ahed of yourself by disqualifying the opinion of people that one can freely assume knows better than any of us, regardless of his courses in school.

 

Your request for a modelling limits of engines „as they truly are“ I find far from practical (especially as you give no details about how to actually implement it), especially if planes should meet the $10 bracket and be profitable. My argument is now how to best approximate what you are dreaming of. And I consider it far from asinine from using temperature as a mean. High powered engines are for the most part temperature restricted and you will produce a lot of steam by just keeping at max. power and happily do what you are doing.

 

The more you max out an engine, the less margin you have. Try to go 10 km at max power with an F1 car. It will blow up half way. It never has to do more than 2 km full power without a cooling period. That is how narrow you can set a window.

 

On most cases, you will overheat your engine in planes like we have them in the game by using exessive power. Keep in mind, optimal cooling is dimensioned to given rated power outputs. You use more power, up goes your heat. Opening rads is adding drag, so you need to open rads further, leading you in a dumb situation. People can learn how to deal with that in the game and they have in real aircraft.

 

Calling that asinine, fine. But what do you call a wish that is not substancuated with a practical way to realize it? Or should we just be fine in having all engines be allowed throttle fully forward, all the time? Can you be more specific how to fix the issue other than people being incompetent or donkeys?

Yes I can be more specifc, gladly. 

 

As you say, modeling the engine complexities that are possible is not practical. I agree with this, and it has been one of the things I am trying to argue. 

 

Here is the thing: Broadly speaking, WEP ratings are set so that if the pilot stays withing those limits, the engine will have an expected life of XXX hours. This number of hours was based on how many missions were expected to be needed. This could obviously vary, and thing from 6 missions to 50. The point here is that we are so far below the breaking point that the time to fail is a matter of missions. It does not have anything to do with what the pilot has to worry about per a single mission (for that same power rating of course).

 

We cant practically, as you seem to agree above, model the extreme complexities that might cause random failure anyhow. I do not deny that the engine might fail anyway. Stuff can break despite best efforts. You could very will lose and engine due to random failure at cruise. So in my view modeling this at all is silly. As I have tried to point out, it opens up a whole additional can of worms. It also has bad effects on multiplayer since you would have all sorts of non-player induced problems. 

 

The aircraft should be modeled in game based on what should, if nothing breaks, happen. In other words, how it performs if it is functioning as intended. Since WEP limits dont actually have anything to do with per mission failure, they should not be modeled at all. This is simply a matter of modeling consistency. Treating the limit as they are now hurts the realistic performance of planes tactically, while at the same time not simulating anything really at all. We are being forced to observe a manual proscription that had nothing to do with what we actually deal with in the time frame of the game. Any ww2 pilot could have done the same thing. It really doesnt mater if you lose 3 missions of engine life if the airplane doesnt return to base at all. 

 

So my proposal is super simple: remove any and all failure due to throttle usage due to time. 

Edited January 3, 2018 by Fumes

[ZachariasX]

Yes I can be more specifc, gladly. 

 

....snipp...

 

So my proposal is super simple: remove any and all failure due to throttle usage due to time.

 

Ok, I see understood you then. Great.

 

So, if we did that, you basically proposed my solution then. Or do you think the engine will not require more cooling when run at higher power outputs?

[LColony_Kong]

Ok, I see understood you then. Great.

 

So, if we did that, you basically proposed my solution then. Or do you think the engine will not require more cooling when run at higher power outputs?

It depends on if the cooling system could manage the heat or not. As has been pointed out, most WEP settings were verified for much longer periods than were allowed for use, so it does not appear that there was any cooling issue. If there was it would seem that it was still below any sort of immediate failure limit. 

 

In my view specific evidence is needed to show that any thermal issue was of immediate concern on a per mission basis. It shouldn't be assumed. However if evidence on a per engine basis points to heat getting so hot that a something would immediately fail (not just be abused) then your solution sounds reasonable. I might also add that it would make sense to evaluate this from a speed perspective as well. You might not get any thermal issues as speed, but you might see them at 120knots. 

[ZachariasX]

It depends on if the cooling system could manage the heat or not. As has been pointed out, most WEP settings were verified for much longer periods than were allowed for use, so it does not appear that there was any cooling issue. If there was it would seem that it was still below any sort of immediate failure limit. 

 

In my view specific evidence is needed to show that any thermal issue was of immediate concern on a per mission basis. It shouldn't be assumed. However if evidence on a per engine basis points to heat getting so hot that a something would immediately fail (not just be abused) then your solution sounds reasonable. I might also add that it would make sense to evaluate this from a speed perspective as well. You might not get any thermal issues as speed, but you might see them at 120knots. 

Cooling solutions are made such that they are suitable to a certain flight configuration. They are made to provide enough heat exchange that it is enough for the rated power outputs stated in the manual. It is therfore that you cannot directly compare engine margins on the test bench with those you have in flight. The test bench has always a cooling solution installed to suit whatever you do with the engine. In the aircraft, you don't have that.

 

As long as it is reasonably cold (it is at altitude) and there is sufficient airflow (you going sufficiently fast) there is no cooling issue. In the game now, we have a very consumer friendly version of the cooling predicament, and you shouldn't take that for granted in the real world. But for our purposes, it helps making the sim a bit more playable, as it removes terminal operating errors that are not obvious to the common player.

 

The margins in the cooling solution of the airplanes cover basically one situation: you extending from a bad situation in a straight line at max speed. You should be able to do so for quiet some time with max power setting. However, you going in tight circles, low speed, throttle firewalled, thus will produce a steaming engine within minutes. (Isn't it then, when you don't have enough power?) Same goes for high power, steep climbs. This will also make you also apreciate hot and humid conditions when trying to take of a heavily loaded aircraft. As in the real world.

 

Hobbyist solutions like Methanol and NOX injection are a different story as can kill your engine within minutes (besides imposing significant weight and range penalties). You really make these standard only in situations of great desperation to max the limits of what you have. It is plausible that your engine is a goner after 5 min of such power.

[LColony_Kong]

Cooling solutions are made such that they are suitable to a certain flight configuration. They are made to provide enough heat exchange that it is enough for the rated power outputs stated in the manual. It is therfore that you cannot directly compare engine margins on the test bench with those you have in flight. The test bench has always a cooling solution installed to suit whatever you do with the engine. In the aircraft, you don't have that.

 

As long as it is reasonably cold (it is at altitude) and there is sufficient airflow (you going sufficiently fast) there is no cooling issue. In the game now, we have a very consumer friendly version of the cooling predicament, and you shouldn't take that for granted in the real world. But for our purposes, it helps making the sim a bit more playable, as it removes terminal operating errors that are not obvious to the common player.

 

The margins in the cooling solution of the airplanes cover basically one situation: you extending from a bad situation in a straight line at max speed. You should be able to do so for quiet some time with max power setting. However, you going in tight circles, low speed, throttle firewalled, thus will produce a steaming engine within minutes. (Isn't it then, when you don't have enough power?) Same goes for high power, steep climbs. This will also make you also apreciate hot and humid conditions when trying to take of a heavily loaded aircraft. As in the real world.

 

Hobbyist solutions like Methanol and NOX injection are a different story as can kill your engine within minutes (besides imposing significant weight and range penalties). You really make these standard only in situations of great desperation to max the limits of what you have. It is plausible that your engine is a goner after 5 min of such power.

I agree with you that in a straight line you could run WEP pretty much as long as needed. 

 

 

When it comes to low speed, examples, I already stated that this might be a issue in some circumstances in one of my past posts. However, I do not think you can assume very specifically that this would be a major problem in a general sense. As with most things in engineering, the cooling solution on the aircraft is almost certainly going to be well beyond what is possible to exceed in most flight regimes. With notable exceptions, such as the Yak 1. But when we have these exceptions, you virtually always have plenty of testimony documenting the issue. 

 

If an airplane didnt have a known general cooling issue, it is should be assumed unless there is better evidence, that simply increasing the power would not cause a general problem. The proof of this is in the pudding, as many engines retained the same cooling solution through multiple iterations of massive power increases. Sometimes on the order of several hundred hp. 

 

In the end what is needed is something very similar to the system in DCS,a system in which I have run WEP in P-51s for over and hour. 

 

However, I still think that if no such system exists, it is more realistic overall to remove the limits from most airplanes. 

 

OR

 

What it we had a relatively simple system where WEP could be used indefinitely without risk of failure except during certain regimes. So for example, if you go below a certain airspeed for X amount of time and you have been using excessive WEP X amount of time, maybe then you can have some semi-random failures. But in other regimes, such as level flight, the risk is zero. At least then the player would know when he was taking a risk, without making that risk all encompassing to the extend of making WEP itself a roulette wheel. 

Edited January 3, 2018 by Fumes

[Nocke]

Fumes, I have the feeling what your arguments come down to is basically a higher absolute maximum power as what we have now. Instead of WEP you would then call that the hard limit. But - based on what data should a developer set that value? They do have the WEP values and use them. That is better then pure fantasy, I think.

[Venturi]

The most generalizable "hard limit" to these engines' power, is always onset of detonation - which destroys an engine in a matter of a few seconds if not checked.

 

Where the onset of detonation occurs, is based on what boost levels (in whatever boost measurement you like) which the fuel-in-question's octane rating will support.

 

The German engines were already rated much closer to this point, having lower octane fuel and thus lower boost limits already, with automatic engine management systems to further reduce user error at "the usable edge" of power delivery. Additionally, the engine management systems automatically highly enriched the fuel mixture to suppress detonation when the throttle was "firewalled". This is what gave the ubiquitous "smoke plume" from the German fighters, that American bomber pilots always noted when the Luftwaffe rose to greet them...

On the other hand 100/130 octane fuels that the Americans and British used, allowed for much higher boost levels.

 

The engines which were pushed beyond the "hard limit" of detonation, failed very quickly indeed. 

 

However, pushing an engine beyond its rated power for too long, could induce hot spots and detonation even if the instantaneous boost level required to cause detonation wasn't reached (but the boost level being close to this point).

 

This has NOTHING to do with coolant or oil temperature (if anything, more closely related to oil temps!).

 

I've written about this before at length...

[Nocke]

So the detonation point/hard limit for an engine without hot spots could be determined, or is known, but actually you would have randomly earlier failure, with higher probabilities for hotter engines?

[Venturi]

Precisely, if the boost was close to the detonation point, as the engine parts like valve heads, spark plug tips got hotter (NOT coolant, or oil even, really) - then the detonation threshold was reduced.

65" seems to be the limit at 130 octane rating for American fuels. German B4 fuel used a different octane rating but it was a significant amount lower.

This is simplified, because the compression ratio has a lot to do with this as well. (You use the compression ratio and the Manifold Pressure to determine the actual cylinder pressures at top dead center of piston stroke).

[Nocke]

my question is, is it possible for the devs to find/calculate/guestimate reliable data for the detonation point as function of fuel quality and mixture for all the planes we have?

i would guess not, but am willing to learn ...

[Venturi]

It is very quantifiable because compression ratios for all engines are documented, so are the maximum boosts that the fuel octane rating supported.

 

However, my response to this general line of thinking is, "if there is no will, there can be no way". I for one, am much more interested in flying a simulator than a game. 

British
Rolls-Royce Merlin 6:1
Rolls-Royce Griffon 6:1
Bristol Perseus 6.75:1
Bristol Hercules 7.0:1
Bristol Centaurus 7.2:1
Napier Sabre 7:1

USA
V1710 6.65:1
Wright R1820 6.45:1
Wright R2600 6.9:1
Wright R3350 6.85:1
PW R1830 6.7:1
PW R2800 6.75:1

German
DB601 6.9:1
DB605 7.5/7.3:1 with 87-octane fuel; 8.5/8.3:1 with 100-octane fuel
DB603 7.5:1 left block, 7.3:1 right block
BMW801 6.5:1
Jumo 211 6.5:1
Jumo 213 6.5:1

Japan
Mitsubishi Kasei 6.6:1
Mitsubishi Kinsei 6.6:1
Nakajima Sakae 7:1

[Nocke]

Thx. I think I got it.

construction details of spark plugs, valves and seats, chamber geometry are minor factors?

[Venturi]

Reductio ad absurdum, my friend.

The significant factors are as I've stated.

[YSoMadTovarisch]

If running WEP kills engine within a few minutes it would have never been allowed in the first place because combat pilots under stress during combat wouldn't be timing how long they've run WEP.

Edited January 4, 2018 by YSoMadTovarisch

[Panthera]

If running WEP kills engine within a few minutes it would have never been allowed in the first place because combat pilots under stress during combat wouldn't be timing how long they've run WEP.

 

Agreed, no manufacturer would ever in a million years approve of running the engine at a power setting that would completely wreck the engine within just 5 min, let alone 1 min.

 

The time limits that were provided were for longevity reasons to stretch the TBOs as much as possible, a key factor in any war of attrition.

 

That the DB605 would be run twice for 5 min at 1.42ata during the initial run-in before installation kind of says it all. If the engine was ever gonna fail it would be during the run-in where all the parts are tightly fitted. Anyone who's ever bought a new motorcycle knows about this as well, you don't approach the limits during the run-in period, and this was even more true back in the old days when everything was individually matched a serial numbered to ensure parts weren't interchanged.

Edited January 4, 2018 by Panthera

[LColony_Kong]

 

But no....the engine is likely to explode if you run it too long! 1 whole hour of climbing. Impossible!

Edited January 4, 2018 by Fumes

[Panthera]

Yeah, hopefully the devs are listening and these stupid time limit failures either get significantly increased (to say 10-15 min to simulate a well worn engine), or ideally completely removed.

[Blutaar]

How often was Notleistung available per DB60X, what was the "cooldown" of it and how much Notleistung time could be squeezed out of the 150-200hrs before overhaul? If it is ones per flight for just 1 minute or 1 minute for the whole engine. How could then a manufacturer justify a guaranteed 1min Notleistung timelimit while he knew that after one minute is over, the engine will randomly fail or needs to be exchanged after lets say 90sec of usage? It seems to be highly unlikely to give such timers with this knowledge without giving clear warnings what would happen if times are exceeded. Also one minute is so little that it is nearly useless and the max speed of the plane is not really usable because of that. Max speed is written in the manual for a reason and not just for the nice number!

 

Im not completely against some form of limitation because i think it is impossible to remove time limits without a massive shitstorm. People got used to it and wont let it go completely while others think that hard limits are more realistic. I guess a thermal solution is the best for what we can hope for with much shorter cooldowns per max boost intervals just like in the Yak1 for example. Or a overall boost time limit that will not recover but needs to be high enough to be usable in combat but short enough to prevent people from using it while not in combat and force them to stay witihin the limits. And on top of that a realism option to remove timers.

[SCG_OpticFlow]

How often was Notleistung available per DB60X, what was the "cooldown" of it and how much Notleistung time could be squeezed out of the 150-200hrs before overhaul? If it is ones per flight for just 1 minute or 1 minute for the whole engine. How could then a manufacturer justify a guaranteed 1min Notleistung timelimit while he knew that after one minute is over, the engine will randomly fail or needs to be exchanged after lets say 90sec of usage? It seems to be highly unlikely to give such timers with this knowledge without giving clear warnings what would happen if times are exceeded. Also one minute is so little that it is nearly useless and the max speed of the plane is not really usable because of that. Max speed is written in the manual for a reason and not just for the nice number!

 

Im not completely against some form of limitation because i think it is impossible to remove time limits without a massive shitstorm. People got used to it and wont let it go completely while others think that hard limits are more realistic. I guess a thermal solution is the best for what we can hope for with much shorter cooldowns per max boost intervals just like in the Yak1 for example. Or a overall boost time limit that will not recover but needs to be high enough to be usable in combat but short enough to prevent people from using it while not in combat and force them to stay witihin the limits. And on top of that a realism option to remove timers.

 

IMO an option to disable the timers should be the first and the easiest step. P40 pilots would like that as well, i presume.

[LukeFF]

Another option could be giving the player an option for different time limits, i.e., 1.5x official limits, 2x, etc.

[Sgt_Joch]

anecdote from "Bodenplatte", John Manhro and Ron Putz, 2004 (excellent book btw)

 

p. 137. Unteroffizier Micheal Vogl of 10/JG 3 is egressing back to base after the attack in a Me109 K4:

 

"..I took a quick look over my shoulder and was just able to see that two aircraft had jumped on me from behind. I immediately recognized them as enemy fighters who tried to intercept us on the way back. From then on I did not look back and only with emergency power and flying on the deck could I be saved. ... Because I flew too long with emergency power, the engine quit and I had to pull up and looked for a place to land. I belly-landed my aircraft south of Kalkar..."

 

so:

 

1. Vogl flew his AC too long at emergency power and the engine was destroyed; and

2. He states matter of factly that the engine quit because he flew too long with emergency power since: i) this is what the pilot manual says; and ii) this is what he learned in his training.

 

p.s. I guess he did not get the memo from PC gamers/wannabe pilots that engine operating limits are just a figment of his imagination. 

[JtD]

I'm pretty sure the engine didn't quit because of elapsed time, rather because of excessive heat or maybe an empty MW50 tank. Engines really don't care about time limits, it's just not in the physics.

[Dakpilot]

anecdote from "Bodenplatte", John Manhro and Ron Putz, 2004 (excellent book btw)

 

p. 137. Unteroffizier Micheal Vogl of 10/JG 3 is egressing back to base after the attack in a Me109 K4:

 

"..I took a quick look over my shoulder and was just able to see that two aircraft had jumped on me from behind. I immediately recognized them as enemy fighters who tried to intercept us on the way back. From then on I did not look back and only with emergency power and flying on the deck could I be saved. ... Because I flew too long with emergency power, the engine quit and I had to pull up and looked for a place to land. I belly-landed my aircraft south of Kalkar..."

 

so:

 

1. Vogl flew his AC too long at emergency power and the engine was destroyed; and

2. He states matter of factly that the engine quit because he flew too long with emergency power since: i) this is what the pilot manual says; and ii) this is what he learned in his training.

 

p.s. I guess he did not get the memo from PC gamers/wannabe pilots that engine operating limits are just a figment of his imagination. 

 

 

But if you can run a P-51 at WEP in DCS for an hour you should be able to do the same in all aircraft in BoS

 

 

Cheers Dakpilot

[LColony_Kong]

anecdote from "Bodenplatte", John Manhro and Ron Putz, 2004 (excellent book btw)

 

p. 137. Unteroffizier Micheal Vogl of 10/JG 3 is egressing back to base after the attack in a Me109 K4:

 

"..I took a quick look over my shoulder and was just able to see that two aircraft had jumped on me from behind. I immediately recognized them as enemy fighters who tried to intercept us on the way back. From then on I did not look back and only with emergency power and flying on the deck could I be saved. ... Because I flew too long with emergency power, the engine quit and I had to pull up and looked for a place to land. I belly-landed my aircraft south of Kalkar..."

 

so:

 

1. Vogl flew his AC too long at emergency power and the engine was destroyed; and

2. He states matter of factly that the engine quit because he flew too long with emergency power since: i) this is what the pilot manual says; and ii) this is what he learned in his training.

 

p.s. I guess he did not get the memo from PC gamers/wannabe pilots that engine operating limits are just a figment of his imagination.

Oh yes, because he inspected the engine to see why it failed. As JTD pointed out the time wasn't the issue, but was likely any number of causes. This pilot is actually a perfect example of the coconut effect that people like your self are arguing for.

 

All hail the coconut effect

[SCG_OpticFlow]

Oh yes, because he inspected the engine to see why it failed. As JTD pointed out the time wasn't the issue, but was likely any number of causes. This pilot is actually a perfect example of the coconut effect that people like your self are arguing for.

 

All hail the coconut effect

 

Or ran out of fuel...

[Sgt_Joch]

Oh yes, because he inspected the engine to see why it failed. As JTD pointed out the time wasn't the issue, but was likely any number of causes. This pilot is actually a perfect example of the coconut effect that people like your self are arguing for.

 

All hail the coconut effect

 

this from the man who thinks DCS is a reference document or boosting an engine is like overclocking a GPU.  

 

you can't cherry-pick evidence to fit your fantasy. So when there is an anecdote from one pilot that he flew at WEP longer than recommended, that is evidence that time limits don't matter but when you have an anecdote from another pilot that his engine self-destructed from excessive heat and/or detonation because he flew at WEP longer than recommended, your answer is that there must be another reason?

 

I can see why it is easy to keep believing the earth is flat. 

[curiousGamblerr]

I'm pretty sure the engine didn't quit because of elapsed time, rather because of excessive heat or maybe an empty MW50 tank. Engines really don't care about time limits, it's just not in the physics.

 

Obviously the engine doesn't care about the time directly. The point is, after a certain amount of time, the physics become unbearable for the mechanical parts of the engine.

 

Yes it could have been any number of things, maybe the engine was already worn, but then again, it's absurd that our engines should work like they're factory fresh every sortie. So a time limit simulates the danger of running the average engine too hard, since the average 109 engine on the front would have had some wear and tear.

 

If folks really want a realism option to disable the timers in single player, I'm all for options so everyone can game as they like. But to disable the timers in multiplayer would lead to complete absurdity, as most 109s cruised around at emergency power in their factory fresh engines. Limitations like this are all about encouraging vaguely realistic behavior- it's bad enough the average online player doesn't care about dying like an actual pilot, if they don't have to care about their engines like an actual pilot, MP will only get more absurd.

[LColony_Kong]

this from the man who thinks DCS is a reference document or boosting an engine is like overclocking a GPU.

 

you can't cherry-pick evidence to fit your fantasy. So when there is an anecdote from one pilot that he flew at WEP longer than recommended, that is evidence that time limits don't matter but when you have an anecdote from another pilot that his engine self-destructed from excessive heat and/or detonation because he flew at WEP longer than recommended, your answer is that there must be another reason?

 

I can see why it is easy to keep believing the earth is flat.

As you well know, the GPU is just analogy to demonstrate a concept.

 

And and you also well know, DCS was referenced simply to indicate that other sims already acknowledge this issue and have other solutions.

 

And I haven't cherry picked anything. You don't seem to understand the difference between evidence in the positive vs evidence in the negative. Pilot anecdote that show engines running extremely long durations over the limit DO provide evidence that the time limits are arbitrary. Pilot examples of failure beyond the limit don't tell us anything about why the engine failed.

 

Not to mention we now have two threads with extensive non-anecdote evidence showing that the limits are just for operational reasons, and are not to prevent per mission failure.

 

But no amount of evidence matters to your camp. Your going to keep on arguing for a coconut effect because heaven forbid you lose your manual simulator that gives as much meaning as possible to studious guage reading and lever pulling.

[-=PHX=-SuperEtendard]

I agree with curiousgamblerr, besides from the 109 there are other planes that would go just happily in max performance mode like the I-16, MiG-3, early La-5, P-40 which gain a really good avantace under these regimes. The Ash-82F modification would be deemed totally unnecessary for example.

 

I also agree that the current 1-1.5 min limit on 1.42 ata is too harsh. I think a compromise should be made so it could be used for say 4-5 mins

[curiousGamblerr]

As you well know, the GPU is just analogy to demonstrate a concept.

 

And and you also well know, DCS was referenced simply to indicate that other sims already acknowledge this issue and have other solutions.

 

And I haven't cherry picked anything. You don't seem to understand the difference between evidence in the positive vs evidence in the negative. Pilot anecdote that show engines running extremely long durations over the limit DO provide evidence that the time limits are arbitrary. Pilot examples of failure beyond the limit don't tell us anything about why the engine failed.

 

Not to mention we now have two threads with extensive non-anecdote evidence showing that the limits are just for operational reasons, and are not to prevent per mission failure.

 

But no amount of evidence matters to your camp. Your going to keep on arguing for a coconut effect because heaven forbid you lose your manual simulator that gives as much meaning as possible to studious guage reading and lever pulling.

 

I get your point about positive and negative evidence, but this is not a clear cut theoretical case like a mathematical proof. The positive anecdote could be just as much a fluke of physics and metallurgy as the negative one.

 

But aside from all of that, I think the debate here is missing the point. This is a tactical combat simulator, not a study sim. It's as much about realism in behavior as it is about realism in aircraft. If 99% of actual pilots (or pilot hours) respected the limits according to training and manuals, knowing the possible danger of ignoring them, then in game we should also need to do so to create the most realistic tactical combat environment. 

 

Maybe the limits are slightly too strict, and maybe the implementation of the random-damage-after-exceeding-limits feature could be improved (e.g. increased chance of damage as time goes on over the limit) but the motivation behind the system is sound, and the current implementation is acceptable for the level of engine simulation we have in game. The devs will only improve all these things, but complete removal of this system would make a joke of this game as far as combat simulation goes.

[LColony_Kong]

I get your point about positive and negative evidence, but this is not a clear cut theoretical case like a mathematical proof. The positive anecdote could be just as much a fluke of physics and metallurgy as the negative one.

 

But aside from all of that, I think the debate here is missing the point. This is a tactical combat simulator, not a study sim. It's as much about realism in behavior as it is about realism in aircraft. If 99% of actual pilots (or pilot hours) respected the limits according to training and manuals, knowing the possible danger of ignoring them, then in game we should also need to do so to create the most realistic tactical combat environment.

 

Maybe the limits are slightly too strict, and maybe the implementation of the random-damage-after-exceeding-limits feature could be improved (e.g. increased chance of damage as time goes on over the limit) but the motivation behind the system is sound, and the current implementation is acceptable for the level of engine simulation we have in game. The devs will only improve all these things, but complete removal of this system would make a joke of this game as far as combat simulation goes.

Realisim in behavior is not a thing. Pilots in game should receive as realistic as possible an aircraft and then let them decide how to fly it. Behavior is subjective. Physics isn't.

 

You might as well put a mechanic in game that causes machine guns to explode if you use illegal burst lengths.

 

The problem is that this treats human behavioral recommendations as if they are hard physics, which makes doing the physics at any level pointless from the outset.

 

You might as well make airplanes break when pilot in game use tactics real ww2 pilots didn't use

[YSoMadTovarisch]

Obviously the engine doesn't care about the time directly. The point is, after a certain amount of time, the physics become unbearable for the mechanical parts of the engine.

 

Yes it could have been any number of things, maybe the engine was already worn, but then again, it's absurd that our engines should work like they're factory fresh every sortie. So a time limit simulates the danger of running the average engine too hard, since the average 109 engine on the front would have had some wear and tear.

 

If folks really want a realism option to disable the timers in single player, I'm all for options so everyone can game as they like. But to disable the timers in multiplayer would lead to complete absurdity, as most 109s cruised around at emergency power in their factory fresh engines. Limitations like this are all about encouraging vaguely realistic behavior- it's bad enough the average online player doesn't care about dying like an actual pilot, if they don't have to care about their engines like an actual pilot, MP will only get more absurd.

Yes, because the 109 doesn't build up heat while using WEP and we can't model engine failure due to overheating instead......