7 1/2 Hour War Emergency Test of Pratt&Whitney R-2800 26 April 1944

[Ehret]

52 minutes ago, Talon_ said:

In contrast the P-47 can fly like this:

 

WEP 5m

Combat 4m

Engine death after those 4m

 

Climb to +7000m, set RPM to 2500-2550rpm, enable water injection and mix 100% - the MP will rise to 61" and that's (MP/rpm) low enough to extend the timer for the whole 15m... Performance will approach (at least level speed) that of the K4... or match it when you have under 50% fuel and 4/6 guns.

[Legioneod]

3 minutes ago, Ehret said:

 

Climb to +7000m, set RPM to 2500-2550rpm, enable water injection and mix 100% - the MP will rise to 61" and that's (MP/rpm) low enough to extend the timer for the whole 15m... Performance will approach (at least level speed) that of the K4... or match it when you have under 50% fuel and 4/6 guns.

Thats besides the point though. The P-47 should be able to go 5min WEP and 15 min combat in sequence just like the K-4. It also shouldnt have to lower settings just to get the full 15min at WEP, this is unrealistic and isnt what the water is for. The 15min of water is for WEP settings of 64" at 2700rpm, nothing less than that.

 

Can water be used at lower settings for longer? sure, but that's not what it's historical use if for.

[Venturi]

6 hours ago, II./JG77_Manu* said:

Probably not exactly like this, but those kind of tests weren't that unusual when testing the boundaries of engines

 

Can we see a simliar 7.5hr test document of 1.98 ata for the DB605?

1 hour ago, II./JG77_Manu* said:

 

P40s max powersetting ...  not possible to use. 

Actually...

[II./JG77_Manu*]

7 minutes ago, Venturi said:

 

Can we see a simliar 7.5hr test document of 1.98 ata for the DB605?

Yeah surely somewhere

[Sgt_Joch]

1 hour ago, Talon_ said:

 

It's more that the 109s can recharge WEP while at Combat while the P-47 actually reduces Combat by flying WEP.

 

You can fly a 45 minute 109 sortie without ever using Continuous power if you like:

 

WEP 10m

Combat 10m

WEP 10m

Combat 10m

WEP 5m

 

After this time your water will run out and you'll only have a few liters of fuel left in a full tank.

 

In contrast the P-47 can fly like this:

 

WEP 5m

Combat 4m

Engine death after those 4m

 

I would not be surprised if that gets tweaked and the P47 gets similar treatment, i.e. 5 min WEP, 5 min recharge, 5 min WEP, etc. Matt alluded to it in a post.

 

 

[Ehret]

36 minutes ago, Legioneod said:

Thats besides the point though. The P-47 should be able to go 5min WEP and 15 min combat in sequence just like the K-4. It also shouldnt have to lower settings just to get the full 15min at WEP, this is unrealistic and isnt what the water is for. The 15min of water is for WEP settings of 64" at 2700rpm, nothing less than that.

 

Can water be used at lower settings for longer? sure, but that's not what it's historical use if for.

 

Yes - I agree. It's an issue and unrealistic, yet... in the sim practice when you have to go higher anyway (64" @ 2700m 5m or 15m isn't going change that much when facing K4s on the deck) you will get the 15m of full power possible in thinner air. Because the turbo-supercharger system will not be able to provide the full 64" anymore should one withhold use of the water injection?

 

I'm just saying that we aren't affected that much by the 5m of WEP issue. It should be changed; I have doubts that it will as long the current combat/emergency system is in the place. Besides the point maybe.

[=RvE=Windmills]

17 minutes ago, Sgt_Joch said:

I would not be surprised if that gets tweaked and the P47 gets similar treatment, i.e. 5 min WEP, 5 min recharge, 5 min WEP, etc. Matt alluded to it in a post. 

 

It would be good to confirm this, would safe a lot of typing and nagging the devs if its already in the works.

[Matt]

30 minutes ago, Sgt_Joch said:

I would not be surprised if that gets tweaked and the P47 gets similar treatment, i.e. 5 min WEP, 5 min recharge, 5 min WEP, etc. Matt alluded to it in a post.

That was just my personal opinion.

 

Actually, my personal opinion is that all these time limits should be a difficulty setting and that it should be possible to deactive them completely. But i don't think this is ever gonna happen.

[Legioneod]

41 minutes ago, Matt said:

That was just my personal opinion.

 

Actually, my personal opinion is that all these time limits should be a difficulty setting and that it should be possible to deactive them completely. But i don't think this is ever gonna happen.

It's sure make the sim alot better if it did.

[Rattlesnake]

You know I realized something: Simply adding something in the tech-chat along the lines of “3:55 of WEP time left” would by itself make the management of planes with less than effectively infinite WEP a lot more comprehensible and improve the situation a great deal, without changing the system itself at all.

We’ve gotten down in the weeds with a lot of this stuff, so I feel like it is important for us all to step back and take a big picture look st that situation:

 

In the last update one of two airplanes added gained the highest boost setting ever used operationally, although it was rare. The other airplane did not get the maximum boost whose use can be documented, despite the fact that this was actually common.

 

Moreover, the airplane of the two which far and away has the best speed, climb, and turn at normal combat altitudes in the game (and equal dive apparently) was also given a much longer maximum power duration. Bear in mind that even given effectively infinite WEP also the second airplane still won’t beat or equal the first really.

 

Now does this seem like the proper course of action to everyone? Because to me it seems like singling out a kid who already has a club foot and making him also put on ankle weights before sending him out to play dodgeball with the other kids. 

Edited November 27, 2018 by CMBailey

[Rebel_Scum]

4 hours ago, Venturi said:

 

Can we see a simliar 7.5hr test document of 1.98 ata for the DB605?

 

IIRC, total engine life for the DB605 was quite a bit shorter than that of the R-2800.

[Talon_]

8 minutes ago, Rebel_Scum said:

 

IIRC, total engine life for the DB605 was quite a bit shorter than that of the R-2800.

 

Generally a block full of .50cal does that to an engine  

[Rebel_Scum]

Just now, Talon_ said:

 

Generally a block full of .50cal does that to an engine  

LOL!

[Ehret]

Something interesting and useful - boost times for the combat power:

52" @ 2700rpm lasts 15m and +3m to engine seizure (as expected)

but

52" @ 2510rpm lasts... 35m and +6m to engine seizure

and

48.5 @ 2510rpm lasts... +1.5h then ran out the fuel

 

So the combat mode flag can be ignored as long you have MP under 50" and  rpm under 2550 it seems. It will ease controlling MP by the boost lever immensely. You can set throttle to 100% and don't care if you just exceeded (by turbo lag) the nominal limit by few inches.

Edited November 28, 2018 by Ehret

[HR_Zunzun]

7 hours ago, CMBailey said:

This would literally give an enormous advantage to people who don’t play very addictively. Run the engine into the ground, wait five hours, do it again. People would actually win dogfights just because they happened to catch their opponents at 5:55:00 engine time or something. You could game it just by jumping in other airplanes and running them like hell, and probably all sorts of other ways I’d have to think about. How about something nice, simple,  and reasonable like 10-15 minutes WEP/however long the water lasts and probably just unlimited combat time for everything?

 

Very interesting, thank you.

[Rebel_Scum]

7 hours ago, CMBailey said:

How about something nice, simple,  and reasonable like 10-15 minutes WEP/however long the water lasts and probably just unlimited combat time for everything?

This by far is the most reasonable solution.

[Talon_]

Fuel is a pretty major limiter of Combat power in these 2000hp late-war birds anyway.

[Stilico]

I love this sim, but my three biggest complaints are the limited number of AI due to performance, the stupidity of said AI, and engine timers. I've gotten more and more bitter, over the years, about these engine timers. At this point, I've just started to think that the reason they exist is to gimp the German and American/British planes in order to make the Russian planes perform better. I would rather just rip the timers out all together and let fuel be the limiting factor.

[Rattlesnake]

27 minutes ago, Stilicho said:

I love this sim, but my three biggest complaints are the limited number of AI due to performance, the stupidity of said AI, and engine timers. I've gotten more and more bitter, over the years, about these engine timers. At this point, I've just started to think that the reason they exist is to gimp the German and American/British planes in order to make the Russian planes perform better. I would rather just rip the timers out all together and let fuel be the limiting factor.

The problem for Russian bias theory is that the arguably more gimped side in BoBP were the allies of USSR.

42 minutes ago, Talon_ said:

Fuel is a pretty major limiter of Combat power in these 2000hp late-war birds anyway.

To reiterate, an artificially increased rate of fuel burn (1.5-2X) might be an elegantly simple way of encouraging both power moderation and realistic fuel loads at takeoff.

Edited November 28, 2018 by CMBailey

[LColony_Kong]

11 hours ago, CMBailey said:

Interesting stuff here .

Iv'e been saying this for ages now :). The WEP time limits only exist to maintain the time before overhaul. They do not exist due to danger of per flight engine destruction when you exceed the time. You can also find this exact same test for the Merlin and the Allison. As well as other evidence, including manuals (spitfire) literally spelling out what I just said. 

 

It should also be exceedingly obvious to everyone that most of the time to climb tests would have been impossible if these limits really killed the engine when exceeded. 

 

 

The engine limits were already bonkers but with bodenplatte its going to get even more crazy. Especially since Il2 forces the player to fly strict combat or military settings, not just WEP. 

47 minutes ago, Rebel_Scum said:

This by far is the most reasonable solution.

Id prefer complete removal of limits. But I would be fairly satisfied with this. Unlimited combat and 15 min of WEP. 

Edited November 28, 2018 by Fumes

[R6ckStar]

1 hour ago, Ehret said:

Something interesting and useful - boost times for the combat power:

52" @ 2700rpm lasts 15m and +3m to engine seizure (as expected)

but

52" @ 2510rpm lasts... 35m and +6m to engine seizure

and

48.5 @ 2510rpm lasts... +1.5h then ran out the fuel

 

So the combat mode flag can be ignored as long you have MP under 50" and  rpm under 2550 it seems. It will ease controlling MP by the boost lever immensely. You can set throttle to 100% and don't care if you just exceeded (by turbo lag) the nominal limit by few inches.

 

This how I've been using the P47, just put the throttle to the wall and control the MAP with the boost, you can really micromanage the Manifold this way.

And also use different amounts of WEP too

[Stilico]

31 minutes ago, CMBailey said:

The problem for Russian bias theory is that the arguably more gimped side in BoBP were the allies of USSR.

 

 

Indeed, but I was referring to the actual Russian made planes, not the sides. I get that it's most likely an unfounded conspiracy theory, but is there a single Russian plane that has significant performance problems due to engine management?  Meanwhile, the German players have been complaining about timer restrictions for ages, and now the American planes are even worse than the German ones. I love the P-40, but it's an absolutely miserable plane to fly with those timers. I can specifically remember a long dogfight I was in with two 109's where I was managing to hold my own until my combat power gave out and killed my engine. Or, how many times have you had another plane on your six and you've needed to go full throttle to try and escape, but you're worried about the timer to the point that it affects your decision making? 

 

No, I don't want players going full WEP in transit, but I know for a fact that, when their life was on the line, the real pilots of these planes couldn't care less about engine maintenance. In fact, the real Russian pilots that we're supposed to be simulating didn't even fly their P-40's this way, and I'm pretty sure that they *did* burn out their planes just using it all the time. /rant

[Rattlesnake]

56 minutes ago, Stilicho said:

 

 

Indeed, but I was referring to the actual Russian made planes, not the sides. I get that it's most likely an unfounded conspiracy theory, but is there a single Russian plane that has significant performance problems due to engine management?  Meanwhile, the German players have been complaining about timer restrictions for ages, and now the American planes are even worse than the German ones. I love the P-40, but it's an absolutely miserable plane to fly with those timers. I can specifically remember a long dogfight I was in with two 109's where I was managing to hold my own until my combat power gave out and killed my engine. Or, how many times have you had another plane on your six and you've needed to go full throttle to try and escape, but you're worried about the timer to the point that it affects your decision making? 

 

No, I don't want players going full WEP in transit, but I know for a fact that, when their life was on the line, the real pilots of these planes couldn't care less about engine maintenance. In fact, the real Russian pilots that we're supposed to be simulating didn't even fly their P-40's this way, and I'm pretty sure that they *did* burn out their planes just using it all the time. /rant

You inspired me to compare the Yak-1 to the 109 F4.
The Yak's engine has 35.1 liters of displacement and gets its maximum power of 1260hp@2700rpm on nominal mode with 1050mm of mercury, which=41.34 inches of mercury.
The 109's engine has 34 liters of displacement and gets it's maximum power of 1350hp@2700rpm at emergency with 1.42 ATA=42.49 inches of mercury.

So let me get this straight. They are both liquid-cooled V-12s. They are almost exactly the same displacement. But the Klimov can last forever while putting out 1260hp, while the DB can only last 3 minutes pulling less than 100 more horsepower with one inch of mercury more boost?!?!?!

But wait, there's more!!! In the game "combat" mode on the 109 is limited to 30 minutes. In this mode it is putting out 1200 horsepower @2500RPM and 1.3 ATA/39 inches of mercury. So we are to believe that the Klimov can survive LONGER putting out more horsepower at higher boost and RPM than the DB can putting out less horsepower at lower boost and RPM? Something doesn't smell right.
 

Edited November 28, 2018 by CMBailey

[Ehret]

15 minutes ago, CMBailey said:

But wait, there's more!!! In the game "combat" mode on the 109 is limited to 30 minutes. In this mode it is putting out 1200 horsepower @2500RPM and 1.3 ATA/39 inches of mercury. So we are to believe that the Klimov can survive LONGER putting out more horsepower at higher boost and RPM than the DB can putting out less horsepower at lower boost and RPM. Something doesn't smell right.

 

Perhaps this video can explain the Klimov "phenomena"?

[Rattlesnake]

18 minutes ago, Ehret said:

 

Perhaps this video can explain the Klimov "phenomena"?

I've seen it and it doesn't for two reasons. The first reason is that the Yak doesn't appear to be one of the planes Greg says it was used on. The second and more important reason is that the Klimov is not doing anything special compared to the DB. Refer to the figures again, especially the last part about combat power. The game is breaking the DB 601 after 30 or so minutes while it is making LESS horsepower at LESS boost at LOWER RPMs than the Klimov can put out for infinity. 

[-=PHX=-SuperEtendard]

The 605 makes 1300 HP for 30 min which is pretty good, you can almost use it as continuous in combat zones. With the Klimov you are stuck with that until mid 1944 before upgrading to 1325 HP of the PF-2. There's the 107, but I think the 1700 HP regime was time limited for that one?.

Not very fun flying M-105PF's Yak-9D vs MW 50 109s at the end of the war if your unit wasn't upgraded with Yak-3 or Yak-9M/U

2200 HP with the Sabre rated for 1 hour at +9 boost (when cleared for +11) would be pretty good in that regard hehe.

Edited November 28, 2018 by -=PHX=-SuperEtendard

[Rattlesnake]

4 minutes ago, -=PHX=-SuperEtendard said:

The 605 makes 1300 HP for 30 min which is pretty good, you can almost use it as continuous. With the Klimov you are stuck with that until mid 1944 before upgrading to 1325 HP of the PF-2. There's the 107, but I think the 1700 HP regime was time limited for that one?.

Not very fun flying M-105PF's Yak-9D vs MW 50 109s at the end of the war if your unit wasn't upgraded with Yak-3 or Yak-9M/U

2200 HP with the Sabre rated for 1 hour at +9 boost (when cleared for +11) would be pretty good in that regard hehe.

Yes, it is true that for all practical online flying purposes 30 minutes=eternity. The point is that DB in game *will* eventually break while under less stress of every kind, while the Klimov will not, while doing more of all the things that cause stress to an engine. This simply doesn't make physical sense and shows the pitfalls of relying on sometimes arbitrary guidelines.

[=362nd_FS=RoflSeal]

3 hours ago, Ehret said:

 

Perhaps this video can explain the Klimov "phenomena"?

Only fitted to Mikukins. D-9s should have something similar

[LukeFF]

8 hours ago, CMBailey said:

You know I realized something: Simply adding something in the tech-chat along the lines of “3:55 of WEP time left” would by itself make the management of planes with less than effectively infinite WEP a lot more comprehensible and improve the situation a great deal, without changing the system itself at all.

 

This wouldn't solve anything for those who don't use technochat.

 

6 hours ago, Stilicho said:

At this point, I've just started to think that the reason they exist is to gimp the German and American/British planes in order to make the Russian planes perform better.

 

It's comments like these that will get the topic closed, so let's not go that way.

Edited November 28, 2018 by LukeFF

[Rattlesnake]

51 minutes ago, LukeFF said:

 

This wouldn't solve anything for those who don't use technochat.

 

A factually true statement. So is “Kaleidoscopes are of no use to the blind”.

 

Edited November 28, 2018 by CMBailey

[HandyNasty]

5 hours ago, CMBailey said:

But wait, there's more!!! In the game "combat" mode on the 109 is limited to 30 minutes. In this mode it is putting out 1200 horsepower @2500RPM and 1.3 ATA/39 inches of mercury. So we are to believe that the Klimov can survive LONGER putting out more horsepower at higher boost and RPM than the DB can putting out less horsepower at lower boost and RPM? Something doesn't smell right.

About the survivability of the engine, and correct me if I'm wrong (I am not that knowledgable in engines), but wouldn't that be an issue of fuel quality? The 87 octane the germans used vs the 95 (100?) octane of the VVS. The low octane grade of the fuel of the LW made engine life rather short, no?

 

[Kurfurst]

Octane number is not a ‘quality’ reference, simply showing the amount in the engine of pressure the fuel can sustain without self detonation, compared to iso-octane (=100).

 

Engines were designed to operate within detonation limits of a given fuel rating. Otherwise they would be very short lived indeed. But regardless of octane number, any fuel gives the same burning energy, and same power. The advantage of higher octane fuel is that the operating pressures can be raised further, and more oxigene can be crammed into the engine allowing to burn more fuel. More fuel burned = more power, but octanes have little to do with it directly (alternatively you can also use a larger displacement, or faster running engine, for example).

 

As a matter of fact, higher octane fuels are usually harder on engine components, due to the high content of additives used - primarly lead or aromatics based - to raise the knock resistance, or octane rating of the fuel. These additived are often either corrosive, or rend to foul valves clearances or eat away the valves,  gaskets etc.

[danielprates]

9 hours ago, Fumes said:

Iv'e been saying this for ages now :). The WEP time limits only exist to maintain the time before overhaul. They do not exist due to danger of per flight engine destruction when you exceed the time. You can also find this exact same test for the Merlin and the Allison. As well as other evidence, including manuals (spitfire) literally spelling out what I just said

 

Something like that crossed my mind, until someone pointed out to me that the test was carried out over several days. So who knows,  maybe it was dozens of 5mins runs. 

 

I am not too happy with how overuse is depicted in the game but you bet, using any piston engine in full throttle for an unchecked ammount of time will ruin in pretty soon.

[Legioneod]

7 minutes ago, danielprates said:

 

Something like that crossed my mind, until someone pointed out to me that the test was carried out over several days. So who knows,  maybe it was dozens of 5mins runs. 

 

I am not too happy with how overuse is depicted in the game but you bet, using any piston engine in full throttle for an unchecked ammount of time will ruin in pretty soon.

Based on the test report it seems like (and this is just speculation based off what I know) but it seems like the test were done in 10min increments over the course of 72 hours.

 

This would coincide with the amount of water that was available to the P-47 at the time which only lasted for 10-11 min at full WEP.

It makes sense if the test were done with max water in mind as I'm sure the military would have wanted to be sure that pilots could get the full amount of WEP available to them if they really needed it.

 

It doesn't make sense to only test at a fraction of what the pilot could actually use, it makes much more sense to test at the very maximum that the pilot could use, in the case of early P-47s this was 10-11min WEP, and in later P-47 it would be 15min WEP.

 

Just keep in mind that when doing test I'm sure it was tested with the aircraft itself in-mind and the amount of water that was available to it. The pilot needs to know that he can push the aircraft if he needs to, doing half test or test with less water makes little sense.

[MiloMorai]

It most probably would be tested with more water than the a/c carried as a safety factor. If the engine, for example be run for 20 minutes in testing then 10 minutes in the a/c should be safely used.

[Legioneod]

2 minutes ago, MiloMorai said:

It most probably would be tested with more water than the a/c carried as a safety factor. If the engine, for example be run for 20 minutes in testing then 10 minutes in the a/c should be safely used.

Agreed. It just doesn't make sense to test it at a lower limit than what was available to the actual aircraft in combat. That would be pretty detrimental to the pilot.

[II./JG77_Manu*]

45 minutes ago, danielprates said:

I am not too happy with how overuse is depicted in the game but you bet, using any piston engine in full throttle for an unchecked ammount of time will ruin in pretty soon.

 

Yes it will, but that didn't keep the pilots away from doing it anyway.

A couple of years ago I posted a source, where Russian P40-E pilots were saying, that they vastly exceeded the rating from the manuals and generally flew full throttle in combat areas, because they didn't like the continuous/combat performance (who can blame them?). This lead to a lot of engine wear. One pilots was reporting, that his P40 wasn't able to exceed 400kph at ground level after 6 weeks, because the engine was worn out. That's why P40 engines had to be switched quite regularly. But there wasn't a single source mentioning critical engine failure during flight because of high boost.

 

There was another source about German aircraft using seals for WEP. If you would want to use WEP, you had to break a seal. Seals would be checked on the ground and the pilot had to have a good explanation why he needed WEP. That was due to cost reasons, because WEP-ing weares an engine down quicker, which obviously leads to more service/engine switching, which costs more money. But not because the engine would blow up ?

[HR_Zunzun]

54 minutes ago, II./JG77_Manu* said:

 

Yes it will, but that didn't keep the pilots away from doing it anyway.

A couple of years ago I posted a source, where Russian P40-E pilots were saying, that they vastly exceeded the rating from the manuals and generally flew full throttle in combat areas, because they didn't like the continuous/combat performance (who can blame them?). This lead to a lot of engine wear. One pilots was reporting, that his P40 wasn't able to exceed 400kph at ground level after 6 weeks, because the engine was worn out. That's why P40 engines had to be switched quite regularly. But there wasn't a single source mentioning critical engine failure during flight because of high boost.

 

There was another source about German aircraft using seals for WEP. If you would want to use WEP, you had to break a seal. Seals would be checked on the ground and the pilot had to have a good explanation why he needed WEP. That was due to cost reasons, because WEP-ing weares an engine down quicker, which obviously leads to more service/engine switching, which costs more money. But not because the engine would blow up ?

 

That why I commented that a possible solution was to simulate wear in the engines if you abuse them.

The problem is very complex anyway. In one hand we know that most of the engines could run at any setting for longer than the pilot manual said without breaking down immediately. But on the other hand, I supposed that many pilots were flying them by the manual like in the sim while others didn´t. And in some engine models in some period of time due to technical faults exceeding the limits did have consequences. Who did what and to what extent and with which consequences?

What I would like is that the developers would offer different consequences for exceeding manual limits (damage vs degraded performance or another system) as a difficult option and let some engine data (and for the same reason damage data) to be exported. That way, in an online campaign, consequences could be imposed on the pilots that abused their engines. The mission designer could, for example, impose flying by the book if he wanted it (could be a system like the current one with engine failing or mission penalties like banning you to use the same model of the plane for  a certain amount of flying time or mission numbers). Other options and ways to simulate it could be possible too.

I think the more the options the better.

[danielprates]

1 hour ago, II./JG77_Manu* said:

 

Yes it will, but that didn't keep the pilots away from doing it anyway.

A couple of years ago I posted a source, where Russian P40-E pilots were saying, that they vastly exceeded the rating from the manuals and generally flew full throttle in combat areas, because they didn't like the continuous/combat performance (who can blame them?). This lead to a lot of engine wear. One pilots was reporting, that his P40 wasn't able to exceed 400kph at ground level after 6 weeks, because the engine was worn out. That's why P40 engines had to be switched quite regularly. But there wasn't a single source mentioning critical engine failure during flight because of high boost.

 

There was another source about German aircraft using seals for WEP. If you would want to use WEP, you had to break a seal. Seals would be checked on the ground and the pilot had to have a good explanation why he needed WEP. That was due to cost reasons, because WEP-ing weares an engine down quicker, which obviously leads to more service/engine switching, which costs more money. But not because the engine would blow up ?

 

That is very interesting historical data. I guess that, as always, the manufacturer sets theoretical limits much lower than the actual proven limit. In some cases for good outstanding reasons (like the Manchester's vulture engine which was prone to catching fire so was intentionally underrated to a lower max power) but, I guess, more generally because an engine should last at least 'x' hours and it would be problematic to have it lasting 1/10th of that. 

 

I think every case is different, but my guess would be (coinciding with your opinion, me thinks) that the most recurrent problem of running in max settings in any plane for, say, 1 or 2 hours, would be not an insta-breakdown, as it is in the game,  but more like a massive wear, in such a way that you could already see a decrease in performance in the very same flight (say, by the time  you are landing). Presuming of course you can run an engine like that and keep it cool, of course. I should imagine that in some situations, running in max settings for too long would bring your oil temperature to uncontrollable levels. 

 

1 hour ago, Legioneod said:

Based on the test report it seems like (and this is just speculation based off what I know) but it seems like the test were done in 10min increments over the course of 72 hours.

 

With such a short run, do you suppose they bothered with some artificial cooling? I mean, 10 mins is not a lot, but for a static run in max settings, it seems to me it is likely to go way above the max oil temperature. 

[Legioneod]

7 minutes ago, danielprates said:

 

With such a short run, do you suppose they bothered with some artificial cooling? I mean, 10 mins is not a lot, but for a static run in max settings, it seems to me it is likely to go way above the max oil temperature. 

Unlikely imo, that would defeat the purpose of the test. It's likely that they would have set up an environment that the aircraft would have likely operated in.

To test the engine outside of normal cooling that the aircraft would experience wouldn't help at all, the whole purpose of the test is to determine the safe/max power usage in normal operating conditions that the aircraft would experience.