Re-engined planes

[Shortround6]

In other words, it took 2 years, plus WEP for Allison to almost equals the performance of R-2600 of 1940/41? I rest my case

Except that the Allison was several hundred pounds lighter, including the radiator, and had about 1/3 the frontal area.

Clear advantage in my eyes - I bet Germans would've ritually sacrifice ms. Eva Braun for availability of a reliable 1500 HP engine for Bf-109s in time of BoB. USA was the only country that had that option available, and they skipped it.

I am sure the Germans would have too. They might have even done it for a good 1500hp bomber engine. The Problem is that the R-2600 as built wouldn't have done much for the altitude performance of the 109.
The diameter of an bare R-2600 is several inches greater than the outside diameter of the cowling of the BMW 801. It is around 600lbs heavier than an early Merlin or an Allison or a DB 601 so even factoring in the weight of radiator and coolant it is around 300lbs heavier. Then you need a heavier propeller and a larger oil tank/oil cooler.
With-out a larger heavier/better supercharger the power of the R-2600 falls off at a lower altitude than the Merlin or DB 601 so performance at 20,000ft is much closer than the take of figures show. An R-2600 that developed 1700hp for take off was using 44.5in of boost or 1.48 atmo of pressure. it was also using low gear in it's supercharger which took about half the power of high gear to drive.

The US may have had reason to skip the option.

 

[tomo pauk]

Except that the Allison was several hundred pounds lighter, including the radiator, and had about 1/3 the frontal area.

Did you include radiator for comparison of frontal areas?
Other planes were re-engind with heavier more draggier engines (also, more powerful) and were better than original ones. And the 1st P-40s had 2 hull MGs, wich would've been not installed (but installed in wings), so the weight increase would be channeled through greater firepower.
When talking about added weights, we need to look at whole plane, not the engine itself, which I've included in my post, BTW, along with wing area reduced to 300 ft^2:

Version with 1750 HP (1942), weighting 7000 lbs empty (650 more then P-40E) would have power loading of 0.25 hp/lb, compared with Fw-190A-8 with 0.245, Bf-109G-6 with 0.25.
Wing loading 35 lb/ft, compared with Fw-190A-8 with 35.8, Bf-109G-6 with 34. So, as good as later German machines.

I am sure the Germans would have too. They might have even done it for a good 1500hp bomber engine. The Problem is that the R-2600 as built wouldn't have done much for the altitude performance of the 109.
The diameter of an bare R-2600 is several inches greater than the outside diameter of the cowling of the BMW 801. It is around 600lbs heavier than an early Merlin or an Allison or a DB 601 so even factoring in the weight of radiator and coolant it is around 300lbs heavier. Then you need a heavier propeller and a larger oil tank/oil cooler.
With-out a larger heavier/better supercharger the power of the R-2600 falls off at a lower altitude than the Merlin or DB 601 so performance at 20,000ft is much closer than the take of figures show. An R-2600 that developed 1700hp for take off was using 44.5in of boost or 1.48 atmo of pressure. it was also using low gear in it's supercharger which took about half the power of high gear to drive.

We can take our comparison three-way perhaps (skipping the turbo-supercharged versions for now):
1. vs. Merlin (hi-alt) DB-601/605 - while I agree that those might better choice for hi-alt job, they were not the option for USAAC in 1940-1943 period
2. vs. Allison, BMW-801, Klimov-105, AM series, Ash-82 series, Merlin (low-alt), plethora of Japanese engines - when R-2600 have had advantage in at least 2 of 3 categories (power, reliability, availability)
3. vs. Sabre, R-2800, Griffon - r-2600 was available far earlier that each of those

The US may have had reason to skip the option.

Italians loved biplanes and loathed inline engines, Germans thought the war ended after they conquered France, Brist thought 2pdr is enough armament for a 40 ton tank, Japanese adored turn'n'burn, and don't get me started about Russkies

 

[tomo pauk]

A more streamlined version of radial-engined Mossie:

 

[Shortround6]

Did you include radiator for comparison of frontal areas?

I seriously doubt the radiator was 2 twice the size of the engine.

Other planes were re-engind with heavier more draggier engines (also, more powerful) and were better than original ones.

True but sometimes it is a question of how much more powerful and at what altitudes. In addition sometimes the new engine was more reliable than the old engine and was desirable from that stand point alone. The Earlier 1600hp R-2600s when equipped with a two speed supercharger were rated at a military power of 1400hp at 11,500ft. If I have done the math correctly this means they should have been good for about 1100hp at 18,000ft. Please compare that with Early Merlins, DB 601s, etc. When comparing to the Russian aircraft please note that at least one source credits an early version of the Ash-82 with 1330hp at 17,716ft.

Maybe your super P-40 would be better than an Allison version, the question is by how much. If the improvement is minor it may not be worth the trouble.

And the 1st P-40s had 2 hull MGs, wich would've been not installed (but installed in wings), so the weight increase would be channeled through greater firepower.
When talking about added weights, we need to look at whole plane, not the engine itself, which I've included in my post, BTW, along with wing area reduced to 300 ft^2:

You have lost me on this section. I was referring just to the weight of the engine installation. moving the guns from the fuselage to the wing may help with the balance but does nothing for power plant comparisons. Using power to weight ratios for empty aircraft seems a little bogus when trying to estimate performance. For trying to estimate performance vrs other aircraft you might what to try the power to weight in flying condition at combat altitude. A normal P-40E is around 7850lbs in such condition (allowing for burning off about 50% of fuel). Figuring your R-2600 powered plane at at least 8000lbs in such a condition ( even allowing for reduced armament of 4 guns) means a power to weight ratio of about .1375hp per pound at 18,000ft. Want to re-figure the German planes?

We can take our comparison three-way perhaps (skipping the turbo-supercharged versions for now):
1. vs. Merlin (hi-alt) DB-601/605 - while I agree that those might better choice for hi-alt job, they were not the option for USAAC in 1940-1943 period
2. vs. Allison, BMW-801, Klimov-105, AM series, Ash-82 series, Merlin (low-alt), plethora of Japanese engines - when R-2600 have had advantage in at least 2 of 3 categories (power, reliability, availability)
3. vs. Sabre, R-2800, Griffon - r-2600 was available far earlier that each of those

You lost me again, what turbo charged versions of which engine were we discussing? the P-38s Allison?
for the rest;
1. True but the idea is try and beat them. if the combination won't do the job why bother? Allison did offer an engine with 9.60 supercharger gears fairly early but it had trouble with the gear sets. When finally used the 9.60 gears sets gave 1125hp at 15,500ft. Not 18,000ft but a much easier "what if".
The Merlin engine used in the P-40F was good for 1120hp at 18,500ft. This seems to have been an option for the USAAC in 1942 and 1943. Since we know how it turned out I am just not seeming the utility of a heavier, draggier version of the plane with little more power at altitude performing a whole lot better.
2. The BMW-801 and the Ash-82 aren't really common in the time period under discussion are they? at least not until the very end. And again if the question is even power available at 18-20,000ft the R-2600 is questionable.
3. Mixing time lines a bit. No question the R-2600 is ahead of the Sabre and the Griffon but it is not that far ahead of the R-2800. In order to ensure your availability of engines factory construction and tooling up have to begin about 1 1/2 to 2 years before the planes go into combat in numbers. What do you know? The US was planning on massive factory construction projects for the R-2800 in the end of summer/fall of 1940.

 

[tomo pauk]

I'll be back tomorrow for a more throughout answer

Now the most streamlining one can do for radial engine, other perhaps to bury it on airframe: P-40 with elongated prop shaft ducted fan, here with 1900 HP.

 

[tomo pauk]

I seriously doubt the radiator was 2 twice the size of the engine.

Never said it was However, when comparing inline vs. radial, we need to take it into account. So there is no 3:1 ratio of frontal crosses, but perhaps 3:2 for P-40 case.

True but sometimes it is a question of how much more powerful and at what altitudes. In addition sometimes the new engine was more reliable than the old engine and was desirable from that stand point alone. The Earlier 1600hp R-2600s when equipped with a two speed supercharger were rated at a military power of 1400hp at 11,500ft. If I have done the math correctly this means they should have been good for about 1100hp at 18,000ft. Please compare that with Early Merlins, DB 601s, etc. When comparing to the Russian aircraft please note that at least one source credits an early version of the Ash-82 with 1330hp at 17,716ft.

1100hp @ 18kft (military rating) was awesome figure for a reliable engine in production in 1940 - Allisons for P-40 were capable for that in 1943. And almost as good as Merlin XX (1100 @ 22kft, but only 1300 for take off).
As for DB-601, I'll bet that it took germans to develop 601E (one for Bf-109F4, in 1941) to better those figures.

Thanks for pointing out my mistake about Ash-82. Guess Russkies were right to re-engine the LaGG-3 into something that would combat Germans on more level terms - as I advocate so far for Americans

About 'etc.' ones, those don't come any near the top-notch engines of 1940.

Maybe your super P-40 would be better than an Allison version, the question is by how much. If the improvement is minor it may not be worth the trouble.

My estimates were that 1940/41 variant (1600 HP, 4 x .50in, wing area down to 200 ft^2, empty weight under 7000 lbs) would be vastly better than any Japanese, Russian or Italian design, better than Spit II Bf-109E, and as good as Bf-109F2 Spit V. Better than any other contemporary US plane, of course
The mid 1942 variant (1750 HP, 4-6 .50in) would've been second only to Spit IX P-38F when at high altitudes (one plane not available for USAAF in more than token numbers, other twice as expensive); as good as Fw-190A-3, better than anything else.
By mid 1943 plethora of (nominally) better planes are available for waring parties, but P-40 has served it's purpose - to hold the enemy until those come to play.

You have lost me on this section. I was referring just to the weight of the engine installation. moving the guns from the fuselage to the wing may help with the balance but does nothing for power plant comparisons. Using power to weight ratios for empty aircraft seems a little bogus when trying to estimate performance. For trying to estimate performance vrs other aircraft you might what to try the power to weight in flying condition at combat altitude. A normal P-40E is around 7850lbs in such condition (allowing for burning off about 50% of fuel). Figuring your R-2600 powered plane at at least 8000lbs in such a condition ( even allowing for reduced armament of 4 guns) means a power to weight ratio of about .1375hp per pound at 18,000ft. Want to re-figure the German planes?

My intention was to show how the increased frontal weight influence at CoG would've been canceled
I don't think it's bogus comparing empty weights, since one loaded weight might differ from another loaded weight (for same plane) for different tasks.
We can do what you propose, but, for re-figuring the German planes, I do lack accurate figures for their power output @ 18kft.

You lost me again, what turbo charged versions of which engine were we discussing? the P-38s Allison?

We are not, so I've made a disclaimer

for the rest;
1. True but the idea is try and beat them. if the combination won't do the job why bother? Allison did offer an engine with 9.60 supercharger gears fairly early but it had trouble with the gear sets. When finally used the 9.60 gears sets gave 1125hp at 15,500ft. Not 18,000ft but a much easier "what if".

Yep, but those 1125 are:
-achieved at WEP rating - so 5-min setting,
-in late 1942
-@ 2500 ft less (minor issue, but still)

The Merlin engine used in the P-40F was good for 1120hp at 18,500ft. This seems to have been an option for the USAAC in 1942 and 1943. Since we know how it turned out I am just not seeming the utility of a heavier, draggier version of the plane with little more power at altitude performing a whole lot better.

1942/43 minus 1940 equals half of length of US WW2. That is the main advantage of 'my' P-40.

2. The BMW-801 and the Ash-82 aren't really common in the time period under discussion are they? at least not until the very end. And again if the question is even power available at 18-20,000ft the R-2600 is questionable.

1600 HP engine was major breakthrough for Germans in late 1941/early 1942 - that is when those HP were relaible, while never being available in numbers needed.
R-2600 offered the same power in 1940, reliable, available. By 1942 it was 1750 HP.

3. Mixing time lines a bit. No question the R-2600 is ahead of the Sabre and the Griffon but it is not that far ahead of the R-2800. In order to ensure your availability of engines factory construction and tooling up have to begin about 1 1/2 to 2 years before the planes go into combat in numbers. What do you know? The US was planning on massive factory construction projects for the R-2800 in the end of summer/fall of 1940.

No mixing here - the group 3 were engines with more HP than R-2600, but with a major shortcoming: not available.

 

[tomo pauk]

Focke Wulf proposed their Fw-189 for a competition eventually won by Hs-129.
Here is how it might've looked the 189 with some HP it really needed. The tail gunner is present - feature Hs-129 lacked all the time. Both crew members are within armor.

 

[hawkeye2an]

Focke Wulf proposed their Fw-189 for a competition eventually won by Hs-129.
Here is how it might've looked the 189 with some HP it really needed. The tail gunner is present - feature Hs-129 lacked all the time. Both crew members are within armor.

Unusual looking bird. Could we see a top view?

 

[tomo pauk]

Ugly, perhaps

Not-that-representative picture, but here it goes:

 

[Burmese Bandit]

Tomo, here is an idea I have had for some time for a really, really fast and long range Mossie Recce Photo plane:

Take a Sabre and put it at the front. Take two DH Gipsy Twelve engines and mount them in pusher configuration, so that not only do they produce less drag, the propellers in pusher produce more thrust and their weight helps to counterbalance the very heavy Sabre in front.

Also have a third Gipsy as a slave engine driving a supercharger in the body. This will give an extra 200 hp to the Sabre and an extra 50 each to the wing Gipsies.

Total, at least 3,300 to 3,500 hp in all.

Performance at least 450 - 460 mph. Very very long range possible if Central Sabre is shut down.

 

[tomo pauk]

(Really had to re-think about this claim, sorry for being boring)

The Merlin engine used in the P-40F was good for 1120hp at 18,500ft. This seems to have been an option for the USAAC in 1942 and 1943. Since we know how it turned out I am just not seeming the utility of a heavier, draggier version of the plane with little more power at altitude performing a whole lot better.

By second half of 1942, R-2600 received 10% more power than the plain 1600 HP version, which should interpolate to 1200 HP @ 18kft, military power. In same time the Merlin XX from P-40F was able to do perhaps 1000 HP @ same alt, military power.
So, 20% more power, for 1-6% increase of weight* (weight difference between complete power-packs was perhaps 400 lbs, almost canceled out by reducing armament ammo to 4 HMGs related ammo). The drag increase (related to bulkier engine) would present the issue, but I've already proposed clipped wings to cut the drag there.

* so not the 7000 lbs empty as I've proposed previously, but 6500 for 4 HMG version.

 

[Shortround6]

(Really had to re-think about this claim, sorry for being boring)


By second half of 1942, R-2600 received 10% more power than the plain 1600 HP version, which should interpolate to 1200 HP @ 18kft, military power. In same time the Merlin XX from P-40F was able to do perhaps 1000 HP @ same alt, military power.
So, 20% more power, for 1-6% increase of weight* (weight difference between complete power-packs was perhaps 400 lbs, almost canceled out by reducing armament ammo to 4 HMGs related ammo). The drag increase (related to bulkier engine) would present the issue, but I've already proposed clipped wings to cut the drag there.

* so not the 7000 lbs empty as I've proposed previously, but 6500 for 4 HMG version.

UH, NO. the R-2600 went from 1600hp to 1700hp not 1750hp. not a 10% increase. It was good for 1450Hp at 14,100ft though. Figuring the difference in air pressure between 14,000ft and 18,500ft the R-2600 should be good for around 1207hp at 18,500ft. I have already told you the Merlin was good for 1120hp at this altitude which was in the section you quoted. Why you knocked it down another 120 hp I have know idea. Difference is less than 10% not 20%. I doubt clipping the wings a bit is going to cancel out the size the the R-2600.

P40Fs were a bit heavier than the E model at just under 7100lbs empty. loosing 180lbs worth of guns doesn't change things much.

For comparison one source for the FW 190A-3 gives an empty weight of 6393lbs with an empty equipped (with guns, radio etc) weight of 7,110lbs and a loaded weight of 8,770lbs. Adjust loaded weight for fuel burned off before combat. Unfortunately for ANY P-40s chances of success the FW 109A-3's engine, while rated at 1700hp for take-off was rated at 1440hp at 18,700ft. giving about a 19% advantage over even your super P-40 not counting the lower drag installation of the FW 190.

Figures I have for the Bf 109F-4 give 1350Hp for take-off but 1300hp at 18,045 ft. this is for a 6400lb plane loaded.

Another thing to note is that the R-2600 can suck down 215 gallons an hour at the 1700hp rating. Or roughly 50% more fuel per minute than an Allison engine, Granted that while cruising the consumption should be somewhat closer but any engine swap might have to consider larger fuel tanks or rather shorter range.

 

[tomo pauk]

Yep, it was 1700 HP in 1942, you're right.

I have already told you the Merlin was good for 1120hp at this altitude which was in the section you quoted. Why you knocked it down another 120 hp I have know idea.

It was WEP figure, so I cut 10% to get military rating. It's 20% difference with R-2600, military rating.

P40Fs were a bit heavier than the E model at just under 7100lbs empty. loosing 180lbs worth of guns doesn't change things much.

Perhaps you mean 'loaded' when stating 7100 lbs figure for P-40F?

For comparison one source for the FW 190A-3 gives an empty weight of 6393lbs with an empty equipped (with guns, radio etc) weight of 7,110lbs and a loaded weight of 8,770lbs.

The empty weight that does not include guns radio is pretty vague number; the 7110 lbs figure makes sense when comparing empty weights. That figure would be equal to 'my' P-40 with 6 guns.

Another thing to note is that the R-2600 can suck down 215 gallons an hour at the 1700hp rating. Or roughly 50% more fuel per minute than an Allison engine, Granted that while cruising the consumption should be somewhat closer but any engine swap might have to consider larger fuel tanks or rather shorter range.

The historical P-40 has had much greater range than Spit or Bf-109 (Wiki says as greater as 'double'), so the minor decrease wouldn't be that detrimental.

 

[tomo pauk]

The Navy use of such P-40 might have a clue... Alternate time line:

-1st aug 1940: after hearing of production of Army plane capable of 375 mph, Navy performs comparison against F2A F4F. 'P-40' soundly defeats the fixed-wing examples of those, so Navy orders a navalized version as a stop gap 'till F4U comes. Main shortcoming is low set pilot's seat.
-1st dec 1940: the F12C, navalized 'P-40' is flown. Wing folds like at SB2C, wing area reversed back to 236 ft, pilot seat raised 1/2 feet, arrester hook. 600 lbs heavier and 10 mph slower then 'P-40' with same gear engine.
-1st june 1941: Curtiss starts production of F-12C
-1st oct 1940: General Motors starts production of FC12 as FM1
-1st dec 1941: 1st carrier wings declared operational with new plane.
(7th dec 1941: Army 'P-40' make IJN take 25% greater losses, while USN loses one BB less. 'P-40s' land with many bullet holes from friendly fire
-may 1942: (Battle of Coral Sea) Lexington CV receives only 1 torpedo hit and makes it to Pearl. Yorktown CV receives only a half of historical bomb hits because of action of their FC12As (with 1700 HP, capable for 375-380 mph)
(-1942: due to plentiful Martlets, RN suffers half of historical casualties on Malta convoys)
-june 1942: (Battle of Midway) four USN carriers sink four IJN carriers for no losses
-july 1942: Navy cancels SB2C project, instead orders the TBF with dive brakes from Grumman; F6F is canceled, Grumman is tasked to develop the plane as light as FC12, but with R-2800 bubble canopy; Navy orders from Curtiss the FC12 with reinforced undercarriage to act as dive brake, plus LE slats; Navy tasks Wright to develop more powerful R-2600; Navy issues request for new all-around attack plane with R-3350
-mid-1943: the FC12B enters production (1750 HP, LE slats, dive bomb to 75 deg, 1500 lbs of bombs), produced also at GM as FM-2
(-late 1943: F4U is in use, F8F 1st flight)
-early 1944: Wright starts production of R-2600 with 1900 HP for T/O, water injection and defined WEP, resulting FC12C (with new engine cowling a-la IJA/IJN planes) making 400+ mph at 18 kft, WEP rating
(-late 1944: F8F in production, 2100 HP; 2400 HP in mid-45)

 

[Shortround6]

It was WEP figure, so I cut 10% to get military rating. It's 20% difference with R-2600, military rating.

It was not a WEP figure. Some figures for the V-1650-1.
take off------------------1390hp/3000rpm?+14lbs boost.
max cont (climb)--------1125hp/2850rpm/+9/9,500ft low gear
max cont (climb)--------1130hp/2850rpm/+9/16,750ft high gear
Max power (combat)---1460hp/3000rpm/+14/6,250ft low gear
Max power (combat)---1430hp/3000rpm/+16/11,000ft low gear

1120hp at 18500ft is not out of line.

Perhaps you mean 'loaded' when stating 7100 lbs figure for P-40F?

Nope.
Sometimes I do make mistakes but in this case I am taking the numbers from the weight charts in "America's Hundred-Thousand" which gives a weigh of 7089lbs "basic" or empty equipped. there is a note that this particular aircraft was 109lbs over the guarantee weight however. To this weight is added 180lbs for pilot and chute, 98lb for oil, 423lbs for .50cal ammo and 888lbs for internal fuel bringing the gross weight to 8678lbs. to this could be added bombs or the ever popular drop tank. Weight for that is 0.5lbs extra piping, 5.0lbs for the rack, 8.6lbs for sway braces, 40lbs for the tank and 312lbs for the fuel. which would put the plane at over 9000lbs.

The empty weight that does not include guns radio is pretty vague number;

It is if you are trying to use it to predict performance.
It is somewhat more useful if you use it to compare two different planes to see how well the designer did at accommodating useful load. Add the disposable load (pilot, ammo, fuel,oil etc) to the military equipment (guns, armor, radio, oxygen,bombs if carried, etc) to get useful load. compare useful load to empty weight to see which designer built the lightest airplane to carry a given a load.

The historical P-40 has had much greater range than Spit or Bf-109 (Wiki says as greater as 'double'), so the minor decrease wouldn't be that detrimental.

that is because it carried more fuel NOT including the drop tank. a P-40E might carry over 120imp gallons of fuel compared to the Spitfires 85Gals. hang 43 imp gal of drop tank underneath and the range does get impressive even if not quite a fair comparison.

of course this a reason for using loaded weights (or partially loaded) when comparing performance. The larger heavier plane will look better when the larger, heavier load is taken out of it.

This fuel thing is one reason the P-40 was always in trouble when compared to the Spitfire and Bf 109. Not the only reason but one of many. Not only do you have a larger fuel load but you have bigger fuel tanks so just not filling them all the way doesn't solve the problem. The unprotected tanks on the original P-40 weighed 171lbs (including pipes), the protected tanks on a P-40E weighed 425lbs. the P-40E is going to be carrying around roughly 130-140lbs more fuel tank even when empty than a Spitfire or 109.

The idea of making the plane heavier while making the wing smaller might have a few problems too. While it helps straight line speed it does impose a few other penalties like higher landing speed.
see:http://www.zenoswarbirdvideos.com/Images/P-40/P-40TOCLC.pdf

 

[Shortround6]

The Navy use of such P-40 might have a clue... Alternate time line:

-1st aug 1940: after hearing of production of Army plane capable of 375 mph, Navy performs comparison against F2A F4F. 'P-40' soundly defeats the fixed-wing examples of those, so Navy orders a navalized version as a stop gap 'till F4U comes. Main shortcoming is low set pilot's seat.

I see, now we are not just substituting the the R-2600 for the allison in an existing airplane, the Allison powered P-40 is never ordered in this alternative time line.

The R-2600 powered plane is ordered back in the Spring of 1939?

well,it is you fantasy

a minor shortcoming might be that a P-40E had a much longer take-off roll than the Navy planes (like around double).

 

[tomo pauk]

Down is what I was able to find out for Merlin XX (a.k.a V-1650-1), on P-40F:

So not the WEP indeed, but it also claims 90 HP less for take-off thany you do
Other figures (but not for max power(combat) - never developed/confirmed for R-2600) seem comfortable within reach even for R-2600 of 1940.

Another question/confirmation - was the max speed reached with 'max power(combat)' - WEP (as I think it was the case)?

The another table (down) claims cca 700 lbs less for every weight category (also from 'P-40 in action'), confirming Wiki. In the Variants P-40F Warhawk, Kittyhawk II site they post another set of data (from Joe Baugher), with values in between (6600 empty)

How about making a definitive guide to P-40?

 

[tomo pauk]

I see, now we are not just substituting the the R-2600 for the allison in an existing airplane, the Allison powered P-40 is never ordered in this alternative time line.

The R-2600 powered plane is ordered back in the Spring of 1939?

well,it is you fantasy

Navy ordered R-2800-powered plane (F4U) in June 1938, so my idea is not that fantastic

a minor shortcoming might be that a P-40E had a much longer take-off roll than the Navy planes (like around double).

2 things
- real P-40s (and P-47, for that matter) were flown from carriers
-we've just mounted more powerful engine to the airframe

 

[tomo pauk]

The data from here:
http://www.raafwarbirds.org.au/targetvraaf/p40_archive/pdfs/1650-1.pdf
claims that WEP for V-1650-1 was 1300 HP, so those figures with 1450 HP don't seem OK

Man, you really make me to do the homework

 

[Shortround6]

Navy ordered R-2800-powered plane (F4U) in June 1938, so my idea is not that fantastic



2 things
- real P-40s (and P-47, for that matter) were flown from carriers
-we've just mounted more powerful engine to the airframe

Yep, but they were never flown into combat from a carrier.

The carrier was used as an aircraft ferry to get the planes close to a land base. Planes were flown ashore and serviced before being used in combat. this means that flight operations could be timed (within reason) for favorable weather conditions and it may mean that the fighters were flown off at less than full loads of fuel and/or ammunition since these loads would be added at the shore base.

your more powerful engine increased the weight which increased the wing loading which increased the minimum flying speed.