For the sake of discussion.. alison engines

[Sublime]

So I read here recently the p40 shares the shame alisson as the 38 and p39.

I can see the similarities in the 40 and 39.

Not the 38

For example my p40 rpm almost always staus at 73% where my p38 usually is at 83%

Whats the deal?

Is this improvements over the war to the engine?

[AndyJWest]

The P-38 has turbochargers. The P-39 & P-40 don't. As for RPM figures, where are you getting a % figure from?

Edited April 2, 2020 by AndyJWest

[RedKestrel]

15 minutes ago, Sublime said:

So I read here recently the p40 shares the shame alisson as the 38 and p39.

I can see the similarities in the 40 and 39.

Not the 38

For example my p40 rpm almost always staus at 73% where my p38 usually is at 83%

Whats the deal?

Is this improvements over the war to the engine?

It's the same engine but different block numbers - actually slightly different block numbers in one engine than the other (presumably for counter-rotating props).
EDIT: I just checked the RPM in the tech specs and its the same between the P-38 and the P-40 - max is 3000 RPM for WEP/Combat and 2600 RPM nominal. The % from the tech tips just indicates the percentage travel of the throttle lever so its not going to be the same in different cockpits even for the same engine. You should go by the RPM on the dial whenever possible, rather than percentage numbers in the tech tips.

Edited April 2, 2020 by RedKestrel

[Lusekofte]

You should stop using tech chat. In special when referring to engine performance. 
The Allisons on the late version of P 38 is different than a early war P 40. 
You need to look at the instruments and read rpm and boost. 
While you cannot exceed 45 boost on the P 40 in this game you can fly continually with it on the P 38. 
And the devs already admitted that P 40engine limits and endurance are wrong. So comparing them is also wrong

[II/JG17_HerrMurf]

22 minutes ago, 216th_LuseKofte said:

And the devs already admitted that P 40engine limits and endurance are wrong. So comparing them is also wrong

 

Can you post the quote or link?

[Lusekofte]

29 minutes ago, II/JG17_HerrMurf said:

 

Can you post the quote or link?

No because Jason was very general in his wording about engine dm on the video

And in last DD they refered to the problem of glass engine. And I assume P 40 is among them. At least I hope he not only ment the radials on fw 190 and P 47 

Edited April 2, 2020 by 216th_LuseKofte

[sevenless]

They were flying recce missions with 2nd TAF in 1944 so bring on those Allison equiped Mustang IIs FR919.

 

[danielprates]

43 minutes ago, 216th_LuseKofte said:

No because Jason was very general in his wording about engine dm on the video

And in last DD they refered to the problem of glass engine. And I assume P 40 is among them. At least I hope he not only ment the radials on fw 190 and P 47 

 

I know I am alone in this, but I like how the engine damage is modelled in the P40 - at least, when you overthrottle in low altitudes, that being a single stage supercharger and thus being able to raise MP far above what it can endure if you do it in low altitudes. I mean, in those cases I kinda expect the engine to just... blow up very quickly.

 

Now, as far as continued use just above the proper regime... there I agree it wears out too fast - as per the general consensus around here.

 

Last dev video was all about new gunfire damage types, but iirc Jason mentioned that new mechanical damage is in the works. Maybe this will be adressed.

[Lusekofte]

1 hour ago, danielprates said:

know I am alone in this, but I like how the engine damage is modelled in the P40

Well after flying it enough. I do not mind the restrictions either. But it get a arcadish feel to it the way it is. 
I find it excellent modeled compared to the 109. It is what you expect it to be. After reading about it. But still I like engine damage to have more parameters than rpm boost timer and heat. It is sort of locked to the clock

[danielprates]

5 minutes ago, 216th_LuseKofte said:

Well after flying it enough. I do not mind the restrictions either. But it get a arcadish feel to it the way it is. 
I find it excellent modeled compared to the 109. It is what you expect it to be. After reading about it. But still I like engine damage to have more parameters than rpm boost timer and heat. It is sort of locked to the clock

 

To be clear, I only like the way you can ruin almost instantly an engine at low altitudes if you go full throttle, which is what I expect in a single-stage supercharged engine of that power. Can't remember right now but if you do that on sealevel, you can go straight away to, what, 20 inches of mercury above the engine's limit, maybe more? That can't be good. Hope they keep it if the P40 goes through an overhaul.

[Sublime]

3 hours ago, 216th_LuseKofte said:

You should stop using tech chat. In special when referring to engine performance. 
The Allisons on the late version of P 38 is different than a early war P 40. 
You need to look at the instruments and read rpm and boost. 
While you cannot exceed 45 boost on the P 40 in this game you can fly continually with it on the P 38. 
And the devs already admitted that P 40engine limits and endurance are wrong. So comparing them is also wrong

Well damnit.  I hate to admit it but its hard to not use tech chat. For one overheats - lotsa instraments are HARD to see if overheating. Otherwise I gues wait till I stream white smoke?

Problem number 2 -- the designer specs will put an rpm or whatever but I noticed it often is lower or doesnt match what peak is percentage wise.

For example the P40. I run it at 74% rpm and dont touch it besides emergencies.  This serves me well.  I dont have glass engine probs.  Idk. Just saying.

As am aside pleasant surprise - i have as much realism on as possible excet technochat says percentages etc.

I was SHOCKED flying a Ju87 to be near my IP and see "Take off power is now restored"

Did they fix that???

So if no technochat remember I got 1 joy and trackir.  How do I turn off all technochat then, and what are your solutions then for being able to see the temps? Not a problem in some planes. Others its frankly a nightmare.

3 hours ago, 216th_LuseKofte said:

You should stop using tech chat. In special when referring to engine performance. 
The Allisons on the late version of P 38 is different than a early war P 40. 
You need to look at the instruments and read rpm and boost. 
While you cannot exceed 45 boost on the P 40 in this game you can fly continually with it on the P 38. 
And the devs already admitted that P 40engine limits and endurance are wrong. So comparing them is also wrong

And boost in mean manifold pressure i presume

[=621=Samikatz]

I think everyone agrees that hard manual limits aren't an ideal way to simulate engine limits, but what is the proposed alternative? It has to be:

 

a) Something objective and measurable, has to be based on some value true to the airplane, can't be done "by feel" or because it "seems right"

b) Something that can be applied equally to all nations and aircraft. If you base it on a certain kind of test, it has to be one everyone has done

 

What else falls under that?

[Jade_Monkey]

6 hours ago, 216th_LuseKofte said:

No because Jason was very general in his wording about engine dm on the video

And in last DD they refered to the problem of glass engine. And I assume P 40 is among them. At least I hope he not only ment the radials on fw 190 and P 47 

They are talking damage model of the engine  regarding bullets and explosions, not engine mgmt. I would not expect that in the upcoming patch.

[41Sqn_Skipper]

3 hours ago, =621=Samikatz said:

I think everyone agrees that hard manual limits aren't an ideal way to simulate engine limits, but what is the proposed alternative? It has to be:

 

a) Something objective and measurable, has to be based on some value true to the airplane, can't be done "by feel" or because it "seems right"

b) Something that can be applied equally to all nations and aircraft. If you base it on a certain kind of test, it has to be one everyone has done

 

What else falls under that?

 

One alternative would be to have a peristent engine status over all servers. 

So by violating the limits slightly in one flight, your engine status is worse in the next flight. This means slightly worse performance and also higher chance for fatal and even random failure (= even without violating limits). 

The same status over all servers.

 

To restore engine status you need to spend maintenance points that would be slowely gained by flight time.

 

Of course crashing the aircraft would need to be considered, e.g. replacement aircraft could be "second hand" and magically have the same engine status. 

 

Could work in career mode or TAW environment. But in general the concept has a lot of flaws ... People would fly on autopilot on empty servers to collect maintenance points. I'd rather take the current system ...

Edited April 3, 2020 by 41Sqn_Banks

[Lusekofte]

7 hours ago, Sublime said:

Well damnit.  I hate to admit it but its hard to not use tech chat. For one overheats - lotsa instraments are HARD to see if overheating. Otherwise I gues wait till I stream white smoke?

Problem number 2 -- the designer specs will put an rpm or whatever but I noticed it often is lower or doesnt match what peak is percentage wise.

For example the P40. I run it at 74% rpm and dont touch it besides emergencies.  This serves me well.  I dont have glass engine probs.  Idk. Just saying.

As am aside pleasant surprise - i have as much realism on as possible excet technochat says percentages etc.

I was SHOCKED flying a Ju87 to be near my IP and see "Take off power is now restored"

Did they fix that???

So if no technochat remember I got 1 joy and trackir.  How do I turn off all technochat then, and what are your solutions then for being able to see the temps? Not a problem in some planes. Others its frankly a nightmare.

And boost in mean manifold pressure i presume

Yes manifoil pressure

 

3 hours ago, Jade_Monkey said:

They are talking damage model of the engine  regarding bullets and explosions, not engine mgmt. I would not expect that in the upcoming patch.

damn 

 

I simply wish for a bit more elegant  solution. 
Thing is the more I fly P 40 and read about it

the more I like it,

I admit I was disappointed when flying it the first year or two. Now I like it, the one and only thing That confuse me is how easy it get total failure, because my impression of allisons was quite opposite.  

[CountZero]

9 hours ago, Sublime said:

...

I was SHOCKED flying a Ju87 to be near my IP and see "Take off power is now restored"

Did they fix that???

...

 

No they didnt fix it. 
You were playing either on Normal realisam or with Instrument Panel option turned on in realisam.
This messages regarding timers expired or recovered show up ONLY when Instrument Panel option is turned on, and that makes no sence and its clear bug as all other techchat messages work on all realisam settings as intendet.

Its like your G limits on/off is controled by unlimited ammo in realisam settings, makes no sence and it would be clear bug.

 

So when they decided that we have this fantasy timers that blow your engines after they expired ( totaly unrealistic and arcade way), and then get recovered after some time, its important that techchat messages that tell player how to play game work bug free. 

As there is no other way to know for sure when timers are out and when they got recharged, and how this flying game works thats what will kill your engine ( totaly unrealistic ) also power settings impact their usage so its never same time as spec say it is and recharges are so random ( totaly unexplained) on airplanes some have 1:1 and some 1:13 ratios betwen used time and recharge times.

If this was working same for real pilots in ww2 that after RECOMENDED time was used up his engine blow up like time bomb, in real airplane there would be alarm bell or big red light informing pilots he used up his 1-3-5min Boost or auto limiter for power or what not ( it was not as real engines dont blow up they just get thier overhaul times shorten by time pilot used up). But as this is just arcade game mehancic made up for this game, and in real life was just recomendation and not important as in game, its IMPORTANT for arcade game that player is informed bug free when timer is out by game and recovered like all other arcade techchat messages ( open canopy gear down and so on showing up on all realisam settings) so we can properly use this fantasy mehanic how its ment to be used by game.

Its simple to fix, its explained where bug is, its basic like bug with like nav lights that you can see brighter as you zoom out from space but for some reason dont get fix.

[kendo]

5 hours ago, 41Sqn_Banks said:

 

One alternative would be to have a peristent engine status over all servers. 

So by violating the limits slightly in one flight, your engine status is worse in the next flight. This means slightly worse performance and also higher chance for fatal and even random failure (= even without violating limits). 

The same status over all servers.

 

To restore engine status you need to spend maintenance points that would be slowely gained by flight time.

 

Of course crashing the aircraft would need to be considered, e.g. replacement aircraft could be "second hand" and magically have the same engine status. 

 

Could work in career mode or TAW environment. But in general the concept has a lot of flaws ... People would fly on autopilot on empty servers to collect maintenance points. I'd rather take the current system ...

 

I had hope for something like this when they announced the Repair/Refuel/Rearm option.

 

It would basically work as you said, except instead of flying around to gain 'maintenance points', the effects would be felt at the Repair/Refuel/Rearm stage.

 

If you had really punished and abused your engine (over several missions quite possibly), there would eventually be a meaningful effect at the Repair stage - and we're not just talking a 5-minute penalty! That wouldn't be realistic and it also would not have any meaningful effect on deterring people from constantly flying around at max emergency power.

 

It would need to reflect your aircraft's engine being stripped down and serviced - so, say, you can't fly on any online servers for 24 hours (yeah, I know...I can hear the howls of anguish already!). Similar effects could also be implemented in Career mode.

 

Repair would also have to be a compulsory feature for Full Real, and not an optional extra that you could choose to avoid.

 

 

Edited April 3, 2020 by kendo

[41Sqn_Skipper]

How about not abusing your engine and just follow the given engine limitations? No need to care about how the limitation is implemented in detail.

If you use combat power twice in a flight and exceed in the allowed duration combined, guess what? You might blow up you engine, so don't do it or accept the random result.

 

1 minute ago, kendo said:

 

I had hope for something like this when they announced the Repair/Refuel/Rearm option.

 

It would basically work as you said, except instead of flying around to gain 'maintenance points', the effects would be felt at the Repair/Refuel/Rearm stage.

 

If you had really punished and abused your engine (over several missions quite possibly), there would eventually be a meaningful effect at the Repair stage - and we're not just talking a 5-minute penalty! That wouldn't be realistic and it also would not have any menaingful effect on deterring people from constantly flying around at max emergency power.

 

It would need to reflect your aircraft's engine being stripped down and serviced - so, say, you can't fly on any online servers for 24 hours (yeah, I know...I can hear the howls of anguish already!). Similar effects could also be implemented in Career mode.

 

Repair would also have to be a compulsory feature for Full Real, and not an optional extra that you could choose to avoid.

 

 

 

That' s an awesome idea. All it would need is to limit the planes by player individuelly so that RRR would be mandatory instead of respawn. Than RRR time could be increased when abusing limits.

[Bremspropeller]

14 hours ago, sevenless said:

They were flying recce missions with 2nd TAF in 1944 so bring on those Allison equiped Mustang IIs FR919.

 

Tac Recce FTW!

[41Sqn_Skipper]

2 minutes ago, Bremspropeller said:

 

Tac Recce FTW!

Allison engined Mustang as collector plane ❤️

[Sublime]

4 hours ago, CountZero said:

 

No they didnt fix it. 
You were playing either on Normal realisam or with Instrument Panel option turned on in realisam.
This messages regarding timers expired or recovered show up ONLY when Instrument Panel option is turned on, and that makes no sence and its clear bug as all other techchat messages work on all realisam settings as intendet.

Its like your G limits on/off is controled by unlimited ammo in realisam settings, makes no sence and it would be clear bug.

 

So when they decided that we have this fantasy timers that blow your engines after they expired ( totaly unrealistic and arcade way), and then get recovered after some time, its important that techchat messages that tell player how to play game work bug free. 

As there is no other way to know for sure when timers are out and when they got recharged, and how this flying game works thats what will kill your engine ( totaly unrealistic ) also power settings impact their usage so its never same time as spec say it is and recharges are so random ( totaly unexplained) on airplanes some have 1:1 and some 1:13 ratios betwen used time and recharge times.

If this was working same for real pilots in ww2 that after RECOMENDED time was used up his engine blow up like time bomb, in real airplane there would be alarm bell or big red light informing pilots he used up his 1-3-5min Boost or auto limiter for power or what not ( it was not as real engines dont blow up they just get thier overhaul times shorten by time pilot used up). But as this is just arcade game mehancic made up for this game, and in real life was just recomendation and not important as in game, its IMPORTANT for arcade game that player is informed bug free when timer is out by game and recovered like all other arcade techchat messages ( open canopy gear down and so on showing up on all realisam settings) so we can properly use this fantasy mehanic how its ment to be used by game.

Its simple to fix, its explained where bug is, its basic like bug with like nav lights that you can see brighter as you zoom out from space but for some reason dont get fix.

Definitely not playing normal realism. And no instrument panel. I have everything but external views off. And yes I sometimes hit "I" for the digi compass.

Technochat as in percentages come up.

But thats it. No labels. Nothing else. Im 100% certain I saw the message and Im 100% because I was shocked as Id never seen it before.

Maybe they didnt fix it, maybe its because some how it was in SP and a PWGC mission, but no it definitely happened. I dont have a screen, but why would I lie?

I agree with the rest sir totally though its off topic.  But no, I dont use any realism helpers. I turn it all off EXCEPT external views.  I only use those for screens sometimes.

Edited April 3, 2020 by Sublime

[Lusekofte]

15 hours ago, danielprates said:

 

To be clear, I only like the way you can ruin almost instantly an engine at low altitudes if you go full throttle, which is what I expect in a single-stage supercharged engine of that power. Can't remember right now but if you do that on sealevel, you can go straight away to, what, 20 inches of mercury above the engine's limit, maybe more? That can't be good. Hope they keep it if the P40 goes through an overhaul.

Yes you are right you can exceed the manifiol pressure by about 20 but you get the same effect by exceeding it with 5 to 10. 
But the more I think of it, I have to say I am in the wrong track here. 
One of the reasons I like the P 39/40 is that I kind of developed a inner clock and feel on how much and long I can abuse the Allison. 
I guess start thinking about it, it is a loong time I have blown a engine. And those millions of dollars I spent in engine blown to learn it is actually well spent money. I think. 

[=621=Samikatz]

10 hours ago, 41Sqn_Banks said:

 

One alternative would be to have a peristent engine status over all servers. 

 

 

I think adding a "meta" background game for a simulator isn't a good choice, personally. It's not especially realistic, has to handwave away too many qeustions, and having to "score points" to get an airplane back to standard would be a weird, immersion breaking feeling

[69th_chuter]

      Various quotes from the 26 August, 1943 "British Army Co-Operational Tactical Employment of the Mustang I (P-51)" by Brig. Gen. C. F. Horn.  Mission type referenced is Rhubarb,

 

 

"Upon reaching the above mentioned point (enemy coast, ed.), the power is increased to maximum cruising (250-270 mph -- 2600 rpm -- 34.5 Hg) and left there during the entire time over enemy territory and until 40 miles away from the enemy coast on the return trip."

 

"At a speed of 270 mph and at zero altitude, the search area is comparatively limited and targets appear quickly.  Experience and alertness are required to pick out these targets in time to make an attack.  It has been found necessary for inexperienced pilots to fly at not over 250 mph until they acquire the necessary skill and experience.  It has also been found that depressing the flaps 5° will have little effect on the speed, but it will change the attitude of the aircraft so that targets can be more easily seen over the nose."

 

"It has been found that speed is not protection or at least not sufficient protection from ground fire and weaving must be employed for maximum protection."
 

"The pilots all like to fly it and its success has been due to its reliability, simplicity and the fact that it is faster than any contemporary aircraft at low and medium altitudes."

 

"The engine (1710-39, ed.) was originally equipped with an automatic boost control limiting the manifold pressure at the lower altitudes to 44".  The British remove this so as to get the vastly increased performance at lower altitudes through the judicious use of over-boost.  As has been mentioned before, they have had exceptionally good service out of these engines ... "

 

"Actual combat has proved that the aircraft can run away from anything the Germans have.  Its only inferior points are that it can't climb as well as the ME 109 and FW 190 and that at the lower speeds of close combat it loses effectiveness of aileron control and therefore has poor rate of roll -- but its turning radius with a slight amount of flap is shorter than either of the German aircraft."

 

"In view of the British operation and the fact that we have an approved war emergency rating on the 1710-39 engine of 56", it is suggested that immediate steps be taken to remove the automatic boost control from our P-51 airplanes in this theatre (Africa, ed.) and that the instrument dials be marked with the proper lights.  The British have operated at full throttle at sea level (72" Hg) for as much as 20 min at a time without hurting the engines.  According to them, the Allison is averaging 1500 hrs between bearing failures as compared to 500 to 600 hrs for the Merlin.  The Allison, they found, will drag them home even with the bearings ruined."

 

 

Also concerning the Allison but in reference to the P-39, a Russian pilot was asked why he thought the Americans didn't like the P-39 while the Russians did and he said that if the Russians had operated the plane "by the book" the way the Americans did the Russians probably wouldn't have liked the P-39 either.  I've forgotten the pilots name ... ?.

 

 

[Venturi]

Nothing new here... but well said...

[ZachariasX]

20 hours ago, chuter said:

It has also been found that depressing the flaps 5° will have little effect on the speed, but it will change the attitude of the aircraft so that targets can be more easily seen over the nose."

This bugs me even more than "The Timer™

". Deploying flaps should TAKE AWAY useful alpha, as it always leads to a nose down configuration. This is even the purpose of flaps besides allowing lower flightspeeds. The added AoA you get from the wing profile for practical purposes should be cancelled by the AC depressing it's nose, leaving you at a net similar attitude, just at lower speeds. Gliders use full span flaps to exactly position their nose in flight direction, minimizing crossection/drag. When going slow, you put the down to get the nose back to where it should be. If you are fast, you set the flaps "upper than up" to get the nose back up. In other words, real flaps work opposite to a lot of what we have in this game. The P-47 being good at circles with flaps is just a logic consequence. With the Spit, it has been corrected somewhat. But on the whole, it is an issue in the general FM.

 

To get the nose up, you have to set flaps up, not down, as we have it in the game. The fact that deployed flaps (depending on their nature) can offer *in principle* a higher AoA does not mitigate that, as the angle of the profile chord increases with regards to the aircraft center line. This eats all the nose-up you get from the flaps, at times even mores so.

 

We can see the game engine doing it wrong in the P-51 video, when flying pattern and doing landings, the differences in attitude tell it all. This is what makes the P-47 in game such a good STOL fighter, and it shouldn't be.

[Bremspropeller]

31 minutes ago, ZachariasX said:

This bugs me even more than "The Timer™

 

Doesn't bug me *more* than the timer, but among the timer and the spotting, it's one of the most glaring issues right now.

[ZachariasX]

Just now, Bremspropeller said:

spotting

Spotting is ok, it's them not being there *until*.?

 

But yeah, it would be nice to cut the Allison some slack.

[69th_Mobile_BBQ]

On 4/2/2020 at 5:47 PM, 216th_LuseKofte said:

 

And in last DD they refered to the problem of glass engine. And I assume P 40 is among them.

 

I took it as all the planes became super easy to engine kill after the new DM was implemented.    

 

I could be wrong, but it doesn't seem to me that the RPM limiter on the P-40 would be the same as the one on the P-38.   There might be the same engine block and necessary parts, but what "peripherals" where also added to the overall build of the engine system?   You can have 2 different cars with the same motor, but different transmission/drive train configurations and 1 might suffer in performance compared to the other.  

[Lusekofte]

23 minutes ago, 69th_Mobile_BBQ said:

I took it as all the planes became super easy to engine kill after the new DM was implemented.    

Yes I think you are right.  
I have partly redrawn my statement and conviction of the fault in P 40. 
I always liked it but hated the hard time limits in it. But at the same time developed a instinctive 

skill on how to not blow the engine and still 

being able to utilize it. 
I still think the limits are to restrictive and dramatic. But I think the plane mirror well what it once where

[gimpy117]

On 4/4/2020 at 7:14 AM, chuter said:

      Various quotes from the 26 August, 1943 "British Army Co-Operational Tactical Employment of the Mustang I (P-51)" by Brig. Gen. C. F. Horn.  Mission type referenced is Rhubarb,

 

 

"Upon reaching the above mentioned point (enemy coast, ed.), the power is increased to maximum cruising (250-270 mph -- 2600 rpm -- 34.5 Hg) and left there during the entire time over enemy territory and until 40 miles away from the enemy coast on the return trip."

 

"At a speed of 270 mph and at zero altitude, the search area is comparatively limited and targets appear quickly.  Experience and alertness are required to pick out these targets in time to make an attack.  It has been found necessary for inexperienced pilots to fly at not over 250 mph until they acquire the necessary skill and experience.  It has also been found that depressing the flaps 5° will have little effect on the speed, but it will change the attitude of the aircraft so that targets can be more easily seen over the nose."

 

"It has been found that speed is not protection or at least not sufficient protection from ground fire and weaving must be employed for maximum protection."
 

"The pilots all like to fly it and its success has been due to its reliability, simplicity and the fact that it is faster than any contemporary aircraft at low and medium altitudes."

 

"The engine (1710-39, ed.) was originally equipped with an automatic boost control limiting the manifold pressure at the lower altitudes to 44".  The British remove this so as to get the vastly increased performance at lower altitudes through the judicious use of over-boost.  As has been mentioned before, they have had exceptionally good service out of these engines ... "

 

"Actual combat has proved that the aircraft can run away from anything the Germans have.  Its only inferior points are that it can't climb as well as the ME 109 and FW 190 and that at the lower speeds of close combat it loses effectiveness of aileron control and therefore has poor rate of roll -- but its turning radius with a slight amount of flap is shorter than either of the German aircraft."

 

"In view of the British operation and the fact that we have an approved war emergency rating on the 1710-39 engine of 56", it is suggested that immediate steps be taken to remove the automatic boost control from our P-51 airplanes in this theatre (Africa, ed.) and that the instrument dials be marked with the proper lights.  The British have operated at full throttle at sea level (72" Hg) for as much as 20 min at a time without hurting the engines.  According to them, the Allison is averaging 1500 hrs between bearing failures as compared to 500 to 600 hrs for the Merlin.  The Allison, they found, will drag them home even with the bearings ruined."

 

 

Also concerning the Allison but in reference to the P-39, a Russian pilot was asked why he thought the Americans didn't like the P-39 while the Russians did and he said that if the Russians had operated the plane "by the book" the way the Americans did the Russians probably wouldn't have liked the P-39 either.  I've forgotten the pilots name ... ?.

 

 

i will mention, these might be fore the smaller supercharger engines, the larger ones according to Allison might not be able to do that. but yes, the Alison is WAAY under modeled in this game IMO. they warn about it in this document http://www.wwiiaircraftperformance.org/P-40/V-1710_Service_Use_of_High_Power_Outputs.pdf

Edited April 5, 2020 by gimpy117

[Venturi]

Yes. Allison was making sure that it didn't have problems with the engines.

 

Think about any manufacturing company which provides a warranty. They have specific parameters for operation, above which they no longer honor the warranty. Allison was being safe (from their perspective) with conservative power ratings for their engines.

 

While this certainly makes sense in peacetime aviation, a different calculus is required in wartime. Remember, the Brits had been at war for three years by Dec 42, and they also had extensive aerial combat experience - reflected in their different operation of the engines as shown in the memo.

 

What this memo proves, by Allison's own statement, is that they were being overly conservative in their ratings for the V-1710 F3R/F4R. They were concerned that the crews in the field, used to ignoring their conservative guidelines on the F3R/F4R, would also ignore the Allison guidelines on use of the new model of engine they were producing, which would result in ACTUAL severe damage.

 

This has been hashed out before in old threads. It would be nice to see it implemented. The historical performance of the P-40 and P-39 (and P-51A) - as used by the British and the Soviets in particular - really was not based on the "official Allison guidelines" but rather on what the pilots could pull on planes that were heavier and had poorer altitude performance than their German and Japanese counterparts at that point in the war.

 

 

 

In my opinion, the pilots used around 55-60" of manifold pressure, given high PN fuel that was supplied - 100/130 at this point in the war.

 

In fact, as shown elsewhere, when Allison installed a manifold pressure regulator in these aircraft (sometime after 1943, long after the P-40E was a prime "front-line" fighter) they magically uprated the engine to 5min at 56" MAP.

 

 

 

There is difficulty in using the engine in the P-40E correctly in the game for two reasons.

 

1, manifold pressure changes dynamically with altitude. This makes constant adjustment of the throttle necessary as you climb or dive, to maintain a consistent MAP.

 

2, the varying RPM of the engine affects manifold pressure. This is partially modeled correctly by IL-2 GB. As shown in the sim, when you are above critical altitude for the engine, increases in RPM (assuming wide open throttle) will increase the MAP. However, below critical altitude, IL-2 GB models this incorrectly. What should occur is that with a fixed throttle, increases in RPM should REDUCE MAP, not increase it. You will find that IL-2 GB simulates this incorrectly.