P-40 Engine Settings as I found them (a bit weird)

[=362nd_FS=RoflSeal]

No you are just being selectively blind...

 

You are conveniently ignoring the second quote where he says that had the been using the settings in the manual they would of all been shot down in both the P-40 and especially the P-39, the P-39 was a "dud" in its manual regimes.

 

You are conveniently ignoring Allison's report on their representatives reporting units in North Africa and the Far East Over boosting F3R and F4R engines to 66" and 70" and then Allison themselves consequently doing tests themselves to find a "safe" limit which they determined to be 60" (due to structural limitations).

 

To you its as if only the first quote is the only one that exists.

Edited March 22, 2016 by RoflSeal

[Original_Uwe]

You know I don't really get it.

With the G2 we are limited to 1.3 ata because pilots ran them at 1.42, accidents and failures were had, and thus documentation was issued limiting the motors to 1.3.

In this case we have the opposite-Allisons limits were very conservative, pilots ran them much harder, and thusly Allison examined the issue and cleared the motors for higher power settings.

So shouldn't the actually used power settings be modeled?

[Crump]

 

 

What is the Time Between Overhauls for an M14P engine ? 

The official time between overhauls on an M14P engine is 750 hours. Until recently it was 500 hours.  Does this mean that like a Lycoming, at the end of that time, they are pretty well worn out and must have all the major components replaced and be recertified?

No it does not! To understand the engine (and the airframes they are installed in) you must first understand the culture and the system in which they were designed to be operated.

In the former Soviet Union, the aircraft were all government property. (You know how carefully people look after government property). If one broke, you requisitioned another.   There were no annual inspections and little if any preventative maintenance. - When I first asked how frequently I should change the oil I was told that they did not bother since after aerobatics, they had to add oil anyway so It was constantly being changed!    In short, the aircraft were designed to be operated in rather agricultural circumstances where technical resources were few.

A further difficulty is that Russian oil is rather crude and does not benefit from the additives we are used to.

Under these circumstances, it is easy to understand why the factory wanted to take a look at each engine every 750 hours or 5 years. If you on do an "annual" every five years, you'd better make it a good one!

When the engines are returned for overhaul, they are often not overhauled as we understand the word, it is more like Inspect And Replace if Necessary (IRAN). The engines are measured and checked. Any worn or defective parts are replaced. The engine is then tested and returned to the field.

When you consider that in the West, we have excellent oil, regular maintenance, annual inspections and we tend to look after what we own, it is clear that a much longer TBO is practical. Pompano Beach Air Center, at one time the importers of Sukhoi aircraft, offered a 2200 hr. guarantee on the engines and I have personally disassembled and inspected an engine with 1000 hours of hard use that had no measurable wear other that a few frayed high tension leads.

I feel quite confident in predicting that when properly looked after, these engines will easily provide at least 2000 hours of reliable operation.

 

 

 

http://www.yak-52.com/faqs.htm#Time Between Overhauls

 

 

 

ou are conveniently ignoring Allison's report on their representatives reporting units in North Africa

 

 

What does an isolated incident in North Africa have to do with the VVS??

[6./ZG26_Klaus_Mann]

You know I don't really get it.

With the G2 we are limited to 1.3 ata because pilots ran them at 1.42, accidents and failures were had, and thus documentation was issued limiting the motors to 1.3.

In this case we have the opposite-Allisons limits were very conservative, pilots ran them much harder, and thusly Allison examined the issue and cleared the motors for higher power settings.

So shouldn't the actually used power settings be modeled?

The G-2s were limited because the DB605 unlike the 601 required more lubrication due to a switch from ball to plain bearings for most engine parts,which had not been considered. This could cause engine fires and failure.

The Aircraft were physically Limited through a throttle stopper, however some pilots removed them initially resulting in casualties and stricter bans on maximum power. In the time period of BoS no Pilots would have been allowed to take off the limiter.

However, the 1.3ata were a useful war-time setting and allowed the G-2 to perform as well as the F-4.

 

The Allison Limits were Peacetime Insurance and maintenance friendly Limits and raised later in the war officially as well.

If you translated the P-40 Manual to the G-2 it would be more like:

 

1 Minute Take-Off at 1.3 ata

5 Minutes at 1.15 ata

Continuous at 0.85 ata

 

This is what the P-40 is in 109 terms right now.

Edited March 22, 2016 by 6./ZG26_Klaus_Mann

[Dakpilot]

I think it is important to read ALL of his interview

 

he does gives specifics of how they used different setting than recommended, but no-where mentions overboosting,

 

He also mentions using P-39 which is also very noted of being used 'harder' by Russian Pilot's and mentions the ONE time where he pushed through the wire and used full boost on the Allison engine, as an anecdote this does not strike me as considering overboosting a general daily occereance

 

It is one thing to wear out engines quicker by using at high power settings, but when a Squadron has blown up all its engines and is now non combat ready someone is going to the firing squad

 

Whist there was certainly experimentation in Western squadrons I don't think it unreasonable to consider that they had much more experience with these engines and definitely better oil and fuel, there are so many reports of P-40 and P-39 using Russian fuel that this IS something to consider

 

Also in game time these reports are around Christmas 42 I would think it unlikely they found their way to Russian front line Squadrons at the time.

 

With some small tweaks the P-40 will be fine for Russian operated, but I agree it would probably need to be adjusted to represent 1943 Western operated aircraft.

 

Unlike real life there is no consequence of destroying your engine, if limits are too generous people will simply fly unhistoric full throttle all the time, in 'Dogfight servers' aircraft will not be representative of historical operation in any way...flat out , get kills burn engine, rinse and repeat (with similar consequences in more realistic servers)

 

Without a much more complicated 'consequence' of extended use of limits, some sort of artificial doctrine/system has to be imposed, or people will fly in a 'performance envelope' that would have (historically) used up every engine, Luftwaffe or VVS (those which can be overboosted) on the whole Eastern front in a matter of months

 

only my opinions 

 

Having blown up a few +1000 hp aircraft engines myself, I consider the mindset where using extreme overboost may 'save you' (90% unlikely..you have already made the situational mistake) and the other side of the coin where blowing your engine will certainly lead to POW status or at worse kill you, or lose it on the next takeoff/critical combat moment

 

Cheers Dakpilot

[Crump]

The G-2s were limited because the DB605 unlike the 601 required more lubrication due to a switch from ball to plain bearings for most engine parts,which had not been considered. This could cause engine fires and failure.

The Aircraft were physically Limited through a throttle stopper, however some pilots removed them initially resulting in casualties and stricter bans on maximum power. In the time period of BoS no Pilots would have been allowed to take off the limiter.

However, the 1.3ata were a useful war-time setting and allowed the G-2 to perform as well as the F-4.

 

The Allison Limits were Peacetime Insurance and maintenance friendly Limits and raised later in the war officially as well.

If you translated the P-40 Manual to the G-2 it would be more like:

 

1 Minute Take-Off at 1.3 ata

5 Minutes at 1.15 ata

Continuous at 0.85 ata

 

This is what the P-40 is in 109 terms right now.

 

 

All of these engines had their power limits raised.  In almost every case, this was due to engineering design changes and nothing to do with "peacetime insurance".  

 

The physics simply do allow the safety margins to be very large if you want to get a heavier than air object off the ground.

[Crump]

Good post, btw Klaus.  Outside of the peacetime insurance, we are in complete agreement.

[6./ZG26_Klaus_Mann]

All of these engines had their power limits raised.  In almost every case, this was due to engineering design changes and nothing to do with "peacetime insurance".  

 

The physics simply do allow the safety margins to be very large if you want to get a heavier than air object off the ground.

No, the DB605As received additional Oil pumps and were physically changed to allow for WEP.

The Allisons 39s remained exactly the same.

I will start a thread at some point, because the P-40 Performance is influenced by Supercharger gearing as well, which would defintely have had an influence on engine life. The tall gearing of some engines could lead to knocking and engine destruction and reduce maximum power as well, but did give more pronounced performance at higher altitudes.

I think I will make a Suggestion concerning this, together with more engine variants for Bf110 and 109E-7

[Crump]

 

 

The Allisons 39s remained exactly the same.

 

I highly doubt they remained the same.

[6./ZG26_Klaus_Mann]

I highly doubt they remained the same.

Well, none of importance to war time service or power output, because there were no problems with the engines. The Allison was a brilliant Combat Engine from the get-go, the Fighters built around it were simply too heavy.

[Crump]

I can contribute a fairly extensive article detailing the design changes....

 

 

 

The Allison was a brilliant Combat Engine from the get-go, the Fighters built around it were simply too heavy.

 

The Allison was a good engine.  It was not any different than any other engine.  It was designed for a specific performance point and when those performance requirements change....it has to be changed as well.

[LukeFF]

What does an isolated incident in North Africa have to do with the VVS??

What does the Lycoming and the Yak-52 have to do with the VVS and the P-40?

[Crump]

It is not lycoming.  The article is about the Russian M14 radial engine series.  It is a very good motor and the article illustrates the low quality and lack of additives found in western aviation oils.

 

That is why the TBO is three times longer with western aviation oil than Russian domestic oil....................................

[MiloMorai]

What does the Lycoming and the Yak-52 have to do with the VVS and the P-40?

 

The Yak-52 flew some 30 years after the GPW ended.

[Crump]

 

 

The Yak-52 flew some 30 years after the GPW ended.

 

And the oil has not improved in quality............. 

[Venturi]

I can contribute a fairly extensive article detailing the design changes....

 

 

 

The Allison was a good engine. It was not any different than any other engine. It was designed for a specific performance point and when those performance requirements change....it has to be changed as well.

Misinformation at its finest. The Allisons in the internal document are per the dash revision changes the SAME.

 

The P38 woes were due to airframe and supercharger specific inter cooler issues at high altitude in ETO. P40 Allisons used a single stage supercharger whose critical altitude was below 18000'. *actually about 15,000'*

 

http://www.ausairpower.net/P-38-Analysis.html

Edited March 23, 2016 by Venturi

[Venturi]

The p40e used the Allison V-1710-39 engine, which is also the variant mentioned in the internal Allison document, above.

Edited March 23, 2016 by Venturi

[Crump]

Misinformation at its finest. The Allisons in the internal document are per the dash revision changes the SAME.

 

The P38 woes were due to airframe and supercharger specific inter cooler issues at high altitude in ETO. P40 Allisons used a single stage supercharger whose critical altitude was below 18000'. *actually about 15,000'*

 

http://www.ausairpower.net/P-38-Analysis.html

 

 

It is all Allison superchargers...

 

Come on.  Does it really make any sense at all that Allison by some miracle was the only engine ever built that could exceed its design point reliably without modification?  No.....

 

[Venturi]

Lol, really? "It is all Allison super chargers."

 

Now I'm convinced you're trolling.

[=362nd_FS=RoflSeal]

It is all Allison superchargers...

 

Come on. Does it really make any sense at all that Allison by some miracle was the only engine ever built that could exceed its design point reliably without modification? No.....

Well Allison themselves tested it and determined up to 60" to be safe maximum after reports from frontline representatives. So, yeah that particular engine seemed to perform above its manual limits.

 

But you seem to ignore it and commit diversions like "what has North Africa got to do with VVS". Oh I don't know maybe they involve the same plane in question?.

Edited March 23, 2016 by RoflSeal

[Crump]

 

 

So, yeah that particular engine seemed to perform above its manual limits.

 

And?

 

So What?  Do you know think that all P-40's in the game should be running above manual limits?

[Crump]

 

 

Oh I don't know maybe they involve the same plane in question?

 

Again?  What does this matter?

 

Open up the aircraft's operating instructions....that is what was approved and used.  Want to know how the vast majority of VVS pilots flew their P-40....open up their manual and read it.

 

You only hear from the survivors and not those who died disregarding the limitations of their airplanes.  You keep coming back to this argument of limits can be exceeded.  Yes they can and the most likely result is not the combat fairey outcome you wish to have of super performance and victory....

[Venturi]

Or, you could go off an official period memorandum from Allison's CHIEF ENGINEER approving an increased nominal...

[LukeFF]

And?

 

So What?  Do you know think that all P-40's in the game should be running above manual limits?

 

Have you even read the Official Letter from Allison itself posted above? For someone yammering on about official, legal limits posted by engine manufacturers, surely a letter from the Chief Engineer of Allison, a Mr. R.M. Hazen, would carry the authority of properly researched limits, right? Surely the head of Allison and those in charge at General Motors, companies clamoring for government contracts, would have reviewed and signed off on said letter being sent to the federal government, right? 

 

I mean, after all, Allison and GM wouldn't have let Mr. Hazen state the following without fact-based research backing him up, right?

 

"The engines under discussion are of the -F3R and -F4R type...on which this company has agreed to the war emergency operation at 60" manifold pressure."

 

How more clear do you need it to be, Crump? The info is right there, for all the world to see.

 

(Certain text bolded, so you cannot claim you did not see it).

Edited March 23, 2016 by LukeFF

[Dakpilot]

Yes, fully agree, but the official letter is from Dec 1942, how long before the actual revision reached Russia and what effect would it have had on the P-40 we have in Russian use in the BoS/BoM timeframe pre revision, for the most part using inferior oil and and certainly not always having the required available fuel needed to run the higher boost

 

perhaps we need two P-40 versions with a revised limits post Jan/Feb '43 version 

 

Cheers Dakpilot

[Crump]

 

 

"The engines under discussion are of the -F3R and -F4R type...on which this company has agreed to the war emergency operation at 60" manifold pressure."

 

Nobody is arguing about the limit being raised to 60"inHG AFTER December of 1943.  That is your own strawman.

 

 

The article I posted discusses the V-1710 C/E/F series....

Yes, the "Allison time bomb" applies to the F3R and F4R engines.  In fact, it is a P-40 in the cartoon.   

 

What is not correct is trying to tie the few North Africa USAAF pilots who gambled on the combat fairey and the misunderstood quote of a VVS pilot as proof that it was normal practice to exceed limitations.

[Crump]

Yes, fully agree, but the official letter is from Dec 1942, how long before the actual revision reached Russia and what effect would it have had on the P-40 we have in Russian use in the BoS/BoM timeframe pre revision, for the most part using inferior oil and and certainly not always having the required available fuel needed to run the higher boost

 

perhaps we need two P-40 versions with a revised limits post Jan/Feb '43 version 

 

Cheers Dakpilot

 

 

It should need that boost increase in 1943 to remain competitive against its contemporary but not in 1941.  It should already be competitive.

 

 

As part of the 6th Air Corps, the 126th IAP flew 666 combat sorties to cover the forces of Kalinin and West Fronts and 318 combat sorties for the defense of Moscow in the period from 25 October 1941 to 25 April 1942. During this effort the regiment downed 29 enemy aircraft at a cost of four of their own aircraft and two pilots. The most intensive period was the first month-685 sorties and 17 kills. But later the regiment was plagued by a continuous series of accidents. The Tomahawk IIB was completely unsuitable for use in the Russian winter. The oil, hydraulic fluid, and antifreeze all froze in temperatures that reached -38° C.

On 38 occasions radiators burst due to freezing temperatures. To provide for repairs all the silver forks had to be confiscated in neighboring villages to be used for soldering. Tires cracked and batteries burst; generators frequently broke and engines seized up. Because the 126th IAP was the first "happy owner" of the Tomahawks, it fell to that unit's maintenance personnel to attempt to rectify this "avalanche" of defects, albeit with the assistance of specialists from the VVS Scientific Research Institute. The generators and tires were changed out for Soviet-produced items and the hydraulic fluid, engine oil, and cooling systems were modified with special petcocks through which the fluids could be completely drained at night. But by the time these specialists had learned how to deal with all the defects, a large portion of the aircraft were already combat incapable. There was a total lack of spare parts and engines (no spare engines had been sent) and even cartridges for the British and American machine guns. Only nine aircraft were in flyable condition by mid-January 1942 [5].

Despite these problems, active combat continued. In January some 198 aircraft sorties were flown (334 flying hours) and 11 aerial engagements were conducted, in which 5 Bf-109s, 1 Ju-88, and 1 He-111 were shot down [6]. These statistics reveal a surprising fact - it turns out that the Tomahawk was fully capable of successful air combat with a Bf-109. The reports of pilots about the circumstances of the engagements confirm this fact. On 18 January 1942, Lieutenants S. V. Levin and I. P. Levsha (in pair) fought an engagement with 7 Bf-109s and shot down two of them without loss. On 22 January a flight of three aircraft led by Lieutenant E. E. Lozov engaged 13 enemy aircraft and shot down two Bf-109Es, again without loss. Altogether in January two Tomahawks were lost-one shot down by German antiaircraft artillery and only one by Messerschmitts.

 

 

The P-40 was a good capable fighter.  If it is not in the game, I would look to other attributes besides tall tales of overboosting.  I have a considerable amount of P-40 documents.

http://lend-lease.airforce.ru/english/articles/romanenko/p-40/

[Crump]

 

 

But the primary source of losses was mechanical failures. Practically not a single combat sortie was flown without some kind of problem. It was a common practice to land with a dead engine. Not all of these flights were completed successfully. On 17 February 1942, one of the best pilots of the regiment, HSU Senior Lieutenant S. G. Ridnyy (Tomahawk AK325) suffered an engine failure on takeoff and was killed in crash. Despite this abundance of accidents and incidents, the general impression of the pilots of 126th IAP regarding this aircraft remained good. The Tomahawk had qualities that were lacking in aircraft of Soviet production.

 

By 1944, the type was obsolete on the Russian Front and no longer competitive.

 

 

 

The low loss rate for the Kittyhawk can be explained by their quite limited employment. Combat experience showed that they were already incapable of contesting with the Bf-109G (especially with the ace pilots of JG 3, JG 51, JG 52, and JG 54). All the summaries regarding the P-40E have a pessimistic tone (insufficient speed and maneuverability, high weight, weak engine), and the conclusions are the same: the aircraft was suitable only for PVO aviation.

It is true that initially the pilots attempted to improve its flight characteristics, primarily by using "war emergency power" during battle. They did this intuitively - if Soviet engines at maximum power roared like beasts, then the Allison only changed its tone slightly and everything seemed normal. The payment came due quickly, however. At "war emergency power" (all of 10 minutes with the Allison engine) the engine quickly wore out and the power fell off markedly.

 

Wow, the first P-40 in the VVS killed its pilot due to the Allison Time bomb....

 

 

 

The first two P-40Es arrived in April 1942 (no. 775 and a second unknown aircraft). An additional 12 arrived in May (nos. 956, 958, 984, 990, 1000-1007 [33]), and the last 10 (1093, 1098, 1102, 1110 - 1116 [34]) in June, a total of 24 aircraft. Combat employment of these aircraft commenced almost immediately, though initially (as was normal) problems arose with the engines. Safonov was the first in the Northern Fleet to obtain a victory with the Kittyhawk - on 17 May he shot down a Ju-88 (confirmed by materials in the Bundesarchiv - Militararchiv in Koblenz). But on 30 May Safonov did not return from a combat sortie in coverage of convoy PQ-16 [35]. The circumstances of his death were not noted in the heat of battle, and the most likely cause is believed to be engine failure. Along with some poor flight characteristics that were exposed during the employment of this aircraft, Safonov's death served to shake the confidence of the unit's pilots in the Kittyhawk.

 

http://lend-lease.airforce.ru/english/articles/romanenko/p-40/

[=362nd_FS=RoflSeal]

So 10 minutes of war emergency power... not 1 minute.

 

Seem to be in line with Ben Kelsey testing of P-38H and G Allisons saying they could be push 60" safely for 7-8 minutes.

Edited March 23, 2016 by RoflSeal

[=362nd_FS=RoflSeal]

Perusing the internet I found this on engine limits relating to Mustang Mk I

Two types of engine F3R and F3R/M

 

First type had a maximum allowed of 45" (56" provided automatic boost control was installed) and second type had full throttle limit of 5 minutes.

 

 

Edited March 23, 2016 by RoflSeal

[Crump]

 

 

So 10 minutes of war emergency power... not 1 minute.

 

 

The April 1943 manual I have shows Military power had been cleared to 15 minutes of use.  So the time restriction was raised between the 1941 manual publication and April 1943.  Curtiss did support the VVS and I imagine they would have known about operating limitation changes in a fairly timely manner. 

[Crump]

Here...

 

From this manual:

 

[=362nd_FS=RoflSeal]

And note War Emergency of 1470hp for 5 minutes

 

Btw document I posted is dated August 1942

Edited March 23, 2016 by RoflSeal

[Crump]

And note War Emergency of 1470hp for 5 minutes

 

Btw document I posted is dated September 1941

  

 

And it still does not sayng anything about running 70" or even 60" manifold pressure.

[=362nd_FS=RoflSeal]

And it still does not sayng anything about running 70" or even 60" manifold pressure.

By FULL THROTTLE for 5 minutes in the F3R/M it kinda implies 60" or even 70".

 

"Standard" F3R seems to have a WEP limit of 56".

 

Crummp I think you are blinded by the fact you don't play the game, ingame the P-40 has a War Emergency of 3000RPM. The whole point of this thread is to show that this was not the case.

 

I may have been focusing too much on units overboosting the engine but from my point of view from the start the devs should of been following this powersetting table.

 

And I think with my document and yours a WEP setting of 56" further enforces that.

Edited March 23, 2016 by RoflSeal

[Crump]

"Standard" F3R seems to have a WEP limit of 56".

 

Yes  The V-1710-39 (F3R) was the engine mounted in the P-40E and does not appear to have ever been cleared for 60"Hg manifold pressure.  It think Klaus was right in there is a similar story to the DB-605's 1.42ata increase.  

 

It was NEVER cleared for 60 inches as of April 1943 or was apparently withdrawn according to the engine manual published three months AFTER the Allison December 1942 memo warning about overboosting. That is obvious from the 1943 Allison engine manual I posted.

 

The only Allison engine cleared for 60" Manifold pressure was the F4R series.

 

The April 1943 P-40E manual clearly shows full throttle is still 44.5" manifold pressure for emergency power....

 

Edited March 23, 2016 by Crump

[=362nd_FS=RoflSeal]

That sheet doesn't mention emergency power, it mentions take-off and military power.

[Crump]

That sheet doesn't mention emergency power, it mentions take-off and military power.

 

I saw that which further reinforces Klaus' conclusion.  The latest information we have is from April 1943 and nothing show's 60"Hg for the F3R engine.  It only shows 56"Hg. After April 43, the P-40E was pretty much obsolete and no further work was done on the type AFAIK.

 

Now, the VVS Operating Instructions are from April 1942 so it some 17 months earlier.  The engine rating should be increased IAW the timeline.

Edited March 23, 2016 by Crump

[Crump]

 

 

By FULL THROTTLE for 5 minutes in the F3R/M it kinda implies 60" or even 70".

 

Not really..... 

[Venturi]

With a single stage supercharger at sea level, with critical alt of 15k, it would have been easy to put to throttle to "the wall" and get 68-70" of boost at sea level. For those used to Soviet engines, this may well have been what they considered "Full Power" but was in fact far over 60". Even so, surviving 10-15 min of this treatment would indicate a few things, one of which is the Soviets used the correct fuel and lubricants, second that the type engine was indeed durable - just that the operators had to use good judgement with a powerful single stage supercharger.

 

Again, going off the official letter which documents real world use of the engines and the sentence "This Company has agreed to the use of 60" WEP limit" should be sufficient to raise the limit of the engines performance. Also, it is a fact that this SIGNIFICANTLY increases the power output of the engine.

 

I disagree with the notion of "changes" being made without revision numbers. For supply chain, manufacturing, standardized replacement parts, the whole lot of issues, one does not simply "change" engine parts or designs on the fly. Especially on a type that had already been relegated to lend lease purposes and export purposes.

 

The bottom line is, anyone can kaboom an engine if the system requires good training and understanding to use it well. The Germans knew this, that's why they automated everything. The Russians knew this, that's why they made every engine limited to "nominal". The Brits and Amis though expected their airmen to use good training and judgement and had complex management setups which allowed for a pilot to perhaps have finer control, but there was equally an easier ability to misuse the equipment.

 

The bottom line is, in game with REAL engine management, one should be able to over post the P40E to 68-70" at will, on the deck -engine consequences be damned. The fact that we are arbitrarily limited to "WEP" settings of 50 something just shows that the modeling of the single stage supercharger is quite off. At least with 60-65" of boost capability we would have more closely the actual mechanical limits of boost, again as documented in the letter. Ideally the devs would also incorporate the semi random failure timer also to better reflect the actual nature of failures.

 

And I would expect anyone who was actually interested in the game and who wished to improve upon it, to actually fly it so as to get an understanding of how it currently is...