P-47 Thunderbolt M1 official engine mod ?

[ZachariasX]

1 hour ago, Voyager said:

I gather one can still get 145/115 today if one is willing to pay for it. 

Up to 180 "octane" in fact, good for ~145 (!) inches MAP on the Merlin along with supplementation of ADI.

 

Today, there's lots of differnent candy in the store:

https://vpracingfuels.com/master-fuel-table/

 

115/145 is just one of them. "Just" ~13 bucks per Gallon. So it's either a nice vacation or filling up the plane at  the pump. Along with the fuel, you can fill in 60 Gallons of M/W50. The 45 Gallons you use as spray water to be pourred on the radiators in flight comes cheap then. This just in case you want +145 boost.

 

So, yes you can get it today, and in contrast to back then, it is real fuel and not that coal producing turd of the fourties.

[Talon_]

8 hours ago, Sgt_Joch said:

1954 P51 manual. Already raised and dealt with here:

 

 

 

1945 called.

[Sgt_Joch]

10 hours ago, Fumes said:

Completely irrelevant. It is the same airplane. 

 

 

 

irrelevant? pointing out that you are quoting a page out of context is not irrelevant.

61" in a 1954 F51 is not WEP, not when the P51H was running at 90".

you also fail the point out that the 1954 maual has exactly the same warnings about exceeding time limits which is found in other manuals.

If you read deeper in the engine operating procedures, they make it clear (p.67) that carburetor air/ engine coolant temperatures have to be kept below a maximum, otherwise there is a "danger of detonation".

 

At p. 82 of the manual dealing specifically with detonation/pre ignition, it is clearly stated that if it occurs, rpm/boost must be immediately reduced, otherwise the engine can be destroyed in seconds.

[ZachariasX]

10 minutes ago, Sgt_Joch said:

If you read deeper in the engine operating procedures, they make it clear (p.67) that carburetor air/ engine coolant temperatures have to be kept below a maximum, otherwise there is a "danger of detonation".

 

At p. 82 of the manual dealing specifically with detonation/pre ignition, it is clearly stated that if it occurs, rpm/boost must be immediately reduced, otherwise the engine can be destroyed in seconds.

Predetonation can occur well below stated maximum manifold pressures if you are operating your engine in a bad way. And yes, predetonation CAN destroy an engine within seconds. HOWEVER, done right, you will NOT have predetonation at stated max. MAP and that "destroyed in seconds" does not apply. This is why they write "in danger of" and not "will happen".

 

It would be nice if predetonation was modelled. But that is not a trivial thing to do.

[BlitzPig_EL]

Much of the issues we are having in our discussions on this subject stems from the fact that most people's knowledge of the internal combustion engine is as follows...

Put key in ignition.  Turn key to start.

Put gear lever in the "D" position.

Step on the pedal on the right.

Done.

 

All this quibbling over the wording of manuals that were written to save the government money on engine repairs has nothing to do with how an engine really works, or it's ability to withstand use in extreme operating regimes.

 

[Sgt_Joch]

Well I do know engines since I used to strip them down, rebuild them and race hot rods in my younger days. 

 

There is a fine line between extracting maximum power and blowing an engine because RPM, boost, compression ratio or just sheer power is too high.

 

Anyone who understands engines and knows the dangers of detonation knows that all this talk that you can run engines at maximum power for an unlimited time is bull.

Edited December 5, 2018 by Sgt_Joch

[Talon_]

5 hours in the case of the V-1650-7...

 

 

Edited December 5, 2018 by Talon_

[sevenless]

58 minutes ago, Talon_ said:

5 hours in the case of the V-1650-7...

 

 

 

So there you have it. 5 minute increment solution we have right now is artificial and should be rectified. The interesting sentence here is:

 

"In fact, the former procedure may even be preferable, as it eliminates temerature cycles which also promote engine wear."

 

So the Mustang is fine with 5 hours WEP before the engine needs inspection, the Thunderbold engine is fine with running 7,5 hours continously at full WEP.

 

Only limiting factor to use WEP Boost should be available water and all else should be left to the discretion of the pilot. I hope the devs rectify this in their next patches. No more silly blowing up engines due to overusage of boost or WEP.

[Sgt_Joch]

it is not WEP, it is 61" which in 1954 on post-war 150 octane AVGAS puts no appreciable strain on the engine. Remember these are peacetime settings.

 

even in 1944, on 100 octane fuel, 61" was considered military (i.e. combat) power with a 15 minute limit.

 

 

Edited December 5, 2018 by Sgt_Joch

[Talon_]

150 octane was not used in peacetime. Allies were already back to 100 octane in May 1945.

[Rattlesnake]

3 hours ago, Sgt_Joch said:

Well I do know engines since I used to strip them down, rebuild them and race hot rods in my younger days. 

 

There is a fine line between extracting maximum power and blowing an engine because RPM, boost, compression ratio or just sheer power is too high.

 

Anyone who understands engines and knows the dangers of detonation knows that all this talk that you can run engines at maximum power for an unlimited time is bull.

The power settings we are discussing in this thread aren't usually the maximum power these engines could possibly produce, these are fighters not racers. Therefore references to engines specialized for the track may not be an apples to apples comparison. This principle is especially applicable to the R-2800.

During durability testing of the C series R-2800 by Republic, it was decided to find out at what manifold pressure and carburetor temperature detonation could be induced. They ran the engine at extreme boost pressures that produced 3,600 hp! But wait, it gets even more amazing. They ran it at 3,600 hp for 250 hours, without any failure! This, with common 100/130 avgas. No special fuels were used. Granted, the engines were completely worn out, but survived without a single component failure. Try that with Rolls Royce Merlin or Allison V-1710.

https://www.456fis.org/P-47M.htm

IIRC the WEP for a  P-47M produced 2800HP. An engine setting that is 800 horsepower below a setting the engine has proved able to survive for 250 hours isn't walking a fine line, it actually has an enormous amount of buffer.

And the Merlin in the P-51H could apparently tolerate at least 90" MAP producing 2200 horsepower with water injection. Keep in mind this was not a stress test, it was cleared for operational use.

Edited December 5, 2018 by CMBailey

[sevenless]

10 minutes ago, CMBailey said:

The power settings we are discussing in this thread aren't usually the maximum power these engines could possibly produce, these are fighters not racers. Therefore references to engines specialized for the track may not be an apples to apples comparison. This principle is especially applicable to the R-2800.

During durability testing of the C series R-2800 by Republic, it was decided to find out at what manifold pressure and carburetor temperature detonation could be induced. They ran the engine at extreme boost pressures that produced 3,600 hp! But wait, it gets even more amazing. They ran it at 3,600 hp for 250 hours, without any failure! This, with common 100/130 avgas. No special fuels were used. Granted, the engines were completely worn out, but survived without a single component failure. Try that with Rolls Royce Merlin or Allison V-1710.

https://www.456fis.org/P-47M.htm

 

Thanks! One more argument against artificial time limits in the game. WEP times at the discretion of the pilot as long as water is present and all is fine and in accordance with published sources.

[=362nd_FS=RoflSeal]

5 hours ago, Sgt_Joch said:

 

irrelevant? pointing out that you are quoting a page out of context is not irrelevant.

61" in a 1954 F51 is not WEP, not when the P51H was running at 90".

you also fail the point out that the 1954 maual has exactly the same warnings about exceeding time limits which is found in other manuals.

If you read deeper in the engine operating procedures, they make it clear (p.67) that carburetor air/ engine coolant temperatures have to be kept below a maximum, otherwise there is a "danger of detonation".

 

At p. 82 of the manual dealing specifically with detonation/pre ignition, it is clearly stated that if it occurs, rpm/boost must be immediately reduced, otherwise the engine can be destroyed in seconds.

F-51H and F-51Ds did not run the same engine, Hs had provisions for water injection. The H is in effect a completely different aircraft.

 

Your highlighted phrases just reinforce the fact that as long as the engine is withing operating temperature windows, WEP is not gonna destroy it in seconds. At the moment the engine destroys itself ingame when these figures are well within

Edited December 5, 2018 by RoflSeal

[Sgt_Joch]

That is a bench test, so not necessarily applicable to production aircraft.

 

it is easy to find examples of actual P47s having issues as soon as they got close to their limit:

 

https://forum.il2sturmovik.com/topic/41212-water-injection-inconsistency-between-k-4-and-p-47d/?do=findComment&comment=698848

[Rattlesnake]

10 minutes ago, Sgt_Joch said:

That is a bench test, so not necessarily applicable to production aircraft.

 

it is easy to find examples of actual P47s having issues as soon as they got close to their limit:

 

https://forum.il2sturmovik.com/topic/41212-water-injection-inconsistency-between-k-4-and-p-47d/?do=findComment&comment=698848

It is also possible to pick examples of every sort of engine ever built failing at completely unremarkable settings because of a variety of factors. Unless you want the game to begin simulating possible but random and unlikely failures your argument here is irrelevant.

And as this example takes into account engines being operated improperly (without water) it is completely irrelevant for this discussion also.

Now Sgt. Joch, if you want to argue that detonation should be modeled, I will gladly help lobby the devs for that, and even more gladly keep a careful eye on temperature while operating in the game, knowing that my engine will stay with me as long as I stay within limits, rather than knowing that it's gonna go kaput in a little over 5 minutes period, no matter what I do.

Edited December 5, 2018 by CMBailey

[=362nd_FS=RoflSeal]

13 minutes ago, Sgt_Joch said:

That is a bench test, so not necessarily applicable to production aircraft.

 

it is easy to find examples of actual P47s having issues as soon as they got close to their limit:

 

https://forum.il2sturmovik.com/topic/41212-water-injection-inconsistency-between-k-4-and-p-47d/?do=findComment&comment=698848

You do realise this was a test, and they also spell out the solution to these detonation problems which is installing a different water jet.

Point is and again you seem to be selectively blind on purpose, then engine was having trouble due to detonation, a malign effect on any engine, not arbitrary timers being exceeded

Edited December 5, 2018 by RoflSeal

[Sgt_Joch]

Just now, RoflSeal said:

 

Your highlighted phrases just reinforce the fact that as long as the engine is withing operating temperature windows, WEP is not gonna destroy it in seconds.

 

agreed. Your point is what?

 

if we had a proper engine and temperature model, you would not worry about limits, you would worry about temperature and WEP would, depending on the circumstances cause the temp to spike causing the pilot to back off of WEP or risk detonation.

 

since we have a very simplified temperature modeling, removing engine limits will just result in players being able to run WEP all the time with no limits, which is worse and much less "realistic" then what we have now.

 

You look at actual combat reports of pilots using WEP  and there are plenty on WW2 Aircraft Performance, they are always in ideal conditions, i.e straight line runs at high altitude or combat dive in a straight line, ideal conditions to keep the engine cool.

 

 

[Rattlesnake]

6 minutes ago, Sgt_Joch said:

 

 

since we have a very simplified temperature modeling, removing engine limits will just result in players being able to run WEP all the time with no limits, which is worse and much less "realistic" then what we have now.

 

You look at actual combat reports of pilots using WEP  and there are plenty on WW2 Aircraft Performance, they are always in ideal conditions, i.e straight line runs at high altitude or combat dive in a straight line, ideal conditions to keep the engine cool.

 

 

Considering the frequent and often deliberate use of WEP beyond limits the engine  going kaput after five minutes is the least realistic of possible compromises. Better was the automatic shutoff solution in Aces High. War Thunder’s temperature based solution also has more merit because at least it is monitorable and analog, and in the spirit of the limitations actually faced by engines.

Edited December 5, 2018 by CMBailey

[Sgt_Joch]

13 minutes ago, CMBailey said:

 

Now Sgt. Joch, if you want to argue that detonation should be modeled, I will gladly help lobby the devs for that, and even more gladly keep a careful eye on temperature while operating in the game, knowing that my engine will stay with me as long as I stay within limits, rather than knowing that it's gonna go kaput in a little over 5 minutes period, no matter what I do.

 

no one is in favor of the current system or think it is ideal. If players want the option to turn off time limits in their own game or on a server, I am all in favour.

 

What I do not agree with is just removing time limits for everyone with the current engine modeling or trying to argue that that is somehow more realistic than the current system.

 

 

Edited December 5, 2018 by Sgt_Joch

[Rattlesnake]

2 minutes ago, Sgt_Joch said:

 

no one is in favor of the current system or think it is ideal. If players want the option to turn off time limits in their own game or on a server, I am all in favour.

 

What I do not agree with is just removing time limits for everyone with the current engine modeling or trying to argue that that is somwhow more realistic than the current system.

 

 

It is not my ideal but it would be an improvement, if you compare actual operations to the game, and has the virtue of simplicity. 

[LColony_Kong]

55 minutes ago, RoflSeal said:

F-51H and F-51Ds did not run the same engine, Hs had provisions for water injection. The H is in effect a completely different aircraft.

 

Your highlighted phrases just reinforce the fact that as long as the engine is withing operating temperature windows, WEP is not gonna destroy it in seconds. At the moment the engine destroys itself ingame when these figures are well within

u beat me to it

6 hours ago, Sgt_Joch said:

 

irrelevant? pointing out that you are quoting a page out of context is not irrelevant.

61" in a 1954 F51 is not WEP, not when the P51H was running at 90".

you also fail the point out that the 1954 maual has exactly the same warnings about exceeding time limits which is found in other manuals.

If you read deeper in the engine operating procedures, they make it clear (p.67) that carburetor air/ engine coolant temperatures have to be kept below a maximum, otherwise there is a "danger of detonation".

 

At p. 82 of the manual dealing specifically with detonation/pre ignition, it is clearly stated that if it occurs, rpm/boost must be immediately reduced, otherwise the engine can be destroyed in seconds.

Other people already pointed out the errors in this post regard it being a F-51D, and about the details of detonation, so I will only cover two things:

 

1) The only relevant context is that it is discussing the reason time limits are in place. It does not matter that it is not referring to WEP, or that it was written in 1954. Its the same plane with the same limits and power settings. If anything it is interesting that they went out of their way to spell this out. 

 

2) XachariasX already went into the details, but I am not even sure why you brought up pg67 to be honest. How on earth did you make the jump from from one thing to the other? Who said there was a overheating problem from high powers?

 

Also, I have stated I am for two different changes to the game. My ideal, and the one I think most mechanically realistic, is to remove all limits except when water runs out. 

 

But I did say that I also find removing all combat/military limits and giving all planes 15min of WEP (or till water runs dry whichever is first) would also be mostly satisfactory. 

 

 

Edited December 5, 2018 by Fumes

[Talon_]

56 minutes ago, Sgt_Joch said:

That is a bench test, so not necessarily applicable to production aircraft.

 

it is easy to find examples of actual P47s having issues as soon as they got close to their limit:

 

https://forum.il2sturmovik.com/topic/41212-water-injection-inconsistency-between-k-4-and-p-47d/?do=findComment&comment=698848

 

76" or ~3,000hp

 

Good thing we have that 400hp buffer on our 2600hp engines at WEP so this shouldn't affect us.

 

 

[Sgt_Joch]

53 minutes ago, Fumes said:

u beat me to it

Other people already pointed out the errors in this post regard it being a F-51D, and about the details of detonation, so I will only cover two things:

 

error that I referred to it as a P51 instead of F51? man, get a life. 

 

and no you are wrong, there is no error in my analysis of "detonation". Try to read and understand for once.

 

53 minutes ago, Fumes said:

 

1) The only relevant context is that it is discussing the reason time limits are in place. It does not matter that it is not referring to WEP, or that it was written in 1954. Its the same plane with the same limits and power settings. If anything it is interesting that they went out of their way to spell this out. 

 

no, you are quoting a page out of context to try to argue that engine limits do not matter , when other comments in the same manual such as at p. 67 and 82 make it clear that the manual contains the exact same warnings about exceeding limits. Here I will repat to make it easier for you:

 

"If you read deeper in the engine operating procedures, they make it clear (p.67) that carburetor air/ engine coolant temperatures have to be kept below a maximum, otherwise there is a "danger of detonation".

 

At p. 82 of the manual dealing specifically with detonation/pre ignition, it is clearly stated that if it occurs, rpm/boost must be immediately reduced, otherwise the engine can be destroyed in seconds."

 

now whether you are doing that because you think no one will notice or you genuily do not understand the concept only you know.

 

53 minutes ago, Fumes said:

 

2) XachariasX already went into the details, but I am not even sure why you brought up pg67 to be honest. How on earth did you make the jump from from one thing to the other? Who said there was a overheating problem from high powers?

 

 see above

 

I have said what I have to say in this thread, so stop quoting me. 

 

[LColony_Kong]

4 minutes ago, Sgt_Joch said:

 

error that I referred to it as a P51 instead of F51? man, get a life. 

 

and no you are wrong, there is no error in my analysis of "detonation". Try to read and understand for once.

 

 

no, you are quoting a page out of context to try to argue that engine limits do not matter , when other comments in the same manual such as at p. 67 and 82 make it clear that the manual contains the exact same warnings about exceeding limits. Here I will repat to make it easier for you:

 

"If you read deeper in the engine operating procedures, they make it clear (p.67) that carburetor air/ engine coolant temperatures have to be kept below a maximum, otherwise there is a "danger of detonation".

 

At p. 82 of the manual dealing specifically with detonation/pre ignition, it is clearly stated that if it occurs, rpm/boost must be immediately reduced, otherwise the engine can be destroyed in seconds."

 

now whether you are doing that because you think no one will notice or you genuily do not understand the concept only you know.

 

 

 see above

 

I have said what I have to say in this thread, so stop quoting me. 

 

Well yes, it makes sense to point out you had the wrong plane. Its one of several....shallow readings of documents that have lead to much confusion on your part. 

 

I am not quoting a page out of context. I am quoting the only page that was relevant to this thread. The page you quote has literally nothing to do with this thread. Where is your evidence that running full power will induce a temperature problem? You are just presuming this. Where is your evidence that running full power causes detonation? Again same thing. The only thing those other sections show is what the pilot is supposed to do if a problem begins. The reason for the problem could be anything. 

 

I am not quoting anything out of context Joch. Rather, you are simply presuming that every section of every manual that lists anything about temperature or detonation is immediately connected to engine failure and WEP in the specific manner in which you are arguing. 

 

[Gambit21]

He’s not trolling, and accusing him of such doesn’t help your position.

 

 

To to everyone else;

 

Don Bryan of the 352nd flew a Jug with increased boost, thanks to his crew chief.

 

I have the info somewhere in one of my phone interviews with him. I’ll try and find it later.

[Talon_]

[HR_Zunzun]

57 minutes ago, Gambit21 said:

He’s not trolling, and accusing him of such doesn’t help your position.

 

 

To to everyone else;

 

Don Bryan of the 352nd flew a Jug with increased boost, thanks to his crew chief.

 

I have the info somewhere in one of my phone interviews with him. I’ll try and find it later.

I have it here.

Spoiler

 

Very nice issue if you love the P-47. It really made me look into the P-47. I suppose you still can get it somewhere.

 

 

 

Edited December 5, 2018 by HR_Zunzun

[sevenless]

@ZUnzun. Thanks! Excellent read and very enlightening on the engine tuning.

[Gambit21]

That’s it!

Saves me some work and much better anyway - thanks.

[Panthera]

I think the crux of the matter here is keeping within the oil & water temperature limits, and as long as you could manage this it didn't really matter what power setting you were running the engine at. In other words you could keep running at max available boost pressure for as long as the oil & water temp needle didn't enter the red zone, you just had to be aware that you were wearing the engine down more rapidly and thus decreasing it's time between overhauls.

 

The 1954 manual even explains why these time limits were put in place to begin with, i.e. to incentivize pilots not to use it unnecessarily - an important guideline during wartime where your logistical systems are already being pushed to their absolute limits, giving little room for reckless operation of valuable equipment. 

 

Edited December 5, 2018 by Panthera

[Rattlesnake]

29 minutes ago, Panthera said:

The 1954 manual even explains why these time limits were put in place to begin with, i.e. to incentivize pilots not to use it unnecessarily - an important guideline during wartime where your logistical systems are already being pushed to their absolute limits, giving little room for reckless operation of valuable equipment. 

 

Veteran describes taking his mechanic up for a ride in his P-47 (he had to sit in the guy's lap to fly) and using the water injection just to show him how it pushed you back in the seat. Hardly a thing to do with an engine so delicate that five minutes of WEP would destroy it.

And also a good sign that these young men WOULD play around with max power settings if you didn't discourage them with stern warnings and procedures, etc.

Edited December 5, 2018 by CMBailey

[HR_Zunzun]

4 hours ago, Panthera said:

I think the crux of the matter here is keeping within the oil & water temperature limits, and as long as you could manage this it didn't really matter what power setting you were running the engine at. In other words you could keep running at max available boost pressure for as long as the oil & water temp needle didn't enter the red zone, you just had to be aware that you were wearing the engine down more rapidly and thus decreasing it's time between overhauls.

 

The 1954 manual even explains why these time limits were put in place to begin with, i.e. to incentivize pilots not to use it unnecessarily - an important guideline during wartime where your logistical systems are already being pushed to their absolute limits, giving little room for reckless operation of valuable equipment. 

 

With all the information have been provided in the last days that is the conclusion I am getting.

The problem with wearing is that is something that hasn´t been simulated so far (I think only A2A). We get a fresh new engine with every mission.Some sort of wearing effect has to be simulated if we want to get rid of any form of "instant bomb" time limits. Could be an accelerated wearing in the mission or taking the wearing effect across several missions (and due to the game nature of the simulator, I think that some form of a link to the player has to be established in this case). 

[Gambit21]

I don't think any long term wear needs to be simulated regardless of the outcome of this discussion. That's going too far, and the 'under the hood' mechanic is just too much coding to be plausible.

 

[Ehret]

29 minutes ago, Gambit21 said:

I don't think any long term wear needs to be simulated regardless of the outcome of this discussion. That's going too far, and the 'under the hood' mechanic is just too much coding to be plausible.

 

Then simplify it: instead of engine seizure we would get decreased power for emergency like 2 or 3 percent less. It'd be marginal and shouldn't change odds much yet a good (psychological at least) incentive to keep your engine fresh as long as possible.

If the pilot keeps the WEP for longer, still, the plane is scrapped after landing, any streak reset and if there is enemy who had some hits then gets a kill.

[HR_Zunzun]

39 minutes ago, Gambit21 said:

I don't think any long term wear needs to be simulated regardless of the outcome of this discussion. That's going too far, and the 'under the hood' mechanic is just too much coding to be plausible.

 

 

I wasn´t referring to simulate something 1:1. But some plausible approximation that makes us feel the effect of "abusing" the engine.  I suppose that something like the loss of power or cooling ability.... could be introduced without having to simulate something so complicated.

[Talon_]

For the curious I make 100 inches of R-2800 power about 3900hp

 

[ZachariasX]

1 hour ago, Talon_ said:

For the curious I make 100 inches of R-2800 power about 3900hp

That's this one then:

Spoiler

But it has an R3350-93 radial. From a Super Connie I gather. So, 500+ mph it is...

 

Edited December 6, 2018 by ZachariasX

[LColony_Kong]

19 hours ago, Ehret said:

 

Then simplify it: instead of engine seizure we would get decreased power for emergency like 2 or 3 percent less. It'd be marginal and shouldn't change odds much yet a good (psychological at least) incentive to keep your engine fresh as long as possible.

If the pilot keeps the WEP for longer, still, the plane is scrapped after landing, any streak reset and if there is enemy who had some hits then gets a kill.

No. Because this would be unrealistic. 

 

What is more this makes no sense from a game play perspective. If it so marginal it has no effect, then why would you even waste the coding time doing it? Psychological effect? To who? Someone who doesnt know it makes no difference?

 

The most realistic solution that doesn't involve a engine model or hyper-detailed persistent multiplayer campaign with a full logistical model..........is to remove the limits. 

[Ehret]

1 hour ago, Fumes said:

No. Because this would be unrealistic. 

 

What is more this makes no sense from a game play perspective. If it so marginal it has no effect, then why would you even waste the coding time doing it? Psychological effect? To who? Someone who doesnt know it makes no difference?

 

To all. The effect would be just on the edge; keeping your engine fresh would be beneficial still and the extending handicap not nearly big enough to make flying with it worthless. Not dissimilar when one forgets to reduce fuel load and realizes that in the middle of sortie. People DO care about small performance advantages. Yet, when handicapped by a minor amount (like taking slight battle damage) most will continue with the mission instead of RTB promptly.

 

For being unrealistic... the very multi-player experience is unrealistic, unfortunately. We don't have logistics, no wear of planes, no military like structure of command, often flying solo semi-randomly. At the top of the unrealistic list would be current artificial combat/emergency timer system. It forces most unrealistic behaviors; this simple proposal would be an improvement and could be implemented quickly. Not a final approach by any means.