1000-1200 HP: long range fighter vs. interceptor? (1 Viewer)

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In order not to clog another thread, here are engine powers at 20000 ft (~ 6km) for some widely-used engines in 1939-41 time frame; no ram effect:
Merlin III: 890
Merlin X: ~925
Merlin XII: ~945
Merlin XX: 1060 (similar for Mk.45)

DB 601A: 800 (similar for Italian and japanese copies; over-revving to 2600 and later to 2800 improved this figure for 601A)
DB 601N: 1020
DB 601E: 1030 (improved to 1130 from late 1941 on)
BMW 801C: 1200

V-1710-33: 860 (similar with -39)

1941:
V-1710 turbo: 1150
R-1830 and R-1820 turbo: 1200
 
In order not to clog another thread, here are engine powers at 20000 ft (~ 6km) for some widely-used engines in 1939-41 time frame; no ram effect:
Merlin III: 890
Merlin X: ~925
Merlin XII: ~945
Merlin XX: 1060 (similar for Mk.45)

DB 601A: 800 (similar for Italian and japanese copies; over-revving to 2600 and later to 2800 improved this figure for 601A)
DB 601N: 1020
DB 601E: 1030 (improved to 1130 from late 1941 on)
BMW 801C: 1200

V-1710-33: 860 (similar with -39)

1941:
V-1710 turbo: 1150
R-1830 and R-1820 turbo: 1200

The military rating on the R-1830 (F4F-4) was 1040hp at 18400ft

Merlin XX output was 1175hp at 20500ft (Hurricane IIA)
 
...
Merlin XX output was 1175hp at 20500ft (Hurricane IIA)

I've seen that figure on some docs (Hurri II and Beaufighter II data sheets), IMO those reflect the 'provisional ratings' given by manufacturer. Courtesy of Neil Stirling:

merl xx provis.JPG

Later charts for all the Merlin 20 series should be more reliable data: chart. The V-1650-1 also follows that chart.
 
In order not to clog another thread, here are engine powers at 20000 ft (~ 6km) for some widely-used engines in 1939-41 time frame; no ram effect:
Merlin III: 890
Merlin X: ~925
Merlin XII: ~945
Merlin XX: 1060 (similar for Mk.45)
and all
R-1830 and R-1820 turbo: 1200

Was looking at the P-40F manual and saw a few numbers that bear on this. for instance take-off of our hypothetical fighter.

A clean P40-F at 7500lbs ( I have no idea ho you get it that light and still have a functional warplane 0on a cold day and running light can clear the 50 obstacle from a hard runway in 1850 ft (zero wind)
at 9300lbs and with the drag of an under fuselage store you need. 3950ft from the hard runway. You need another few hundred feet from sod or soft surface
At 8500lbs it needs 10.6 minutes and 39 gallons of gas to get to 20,000ft
At 9300lbs it needs 17.5 minutes and 51 gallons of gas to get to 20,000ft if the extra weight is a drop tank or bomb/
At 9300lbs but clean it needs 13.3 minutes and 44 gallons of gas to get to 20,000ft.

Adding hundreds of pounds to 1000-1200hp fighters could affect take-off (can't use existing fields) and initial climb out to the extent you aren't going to get the range increase you might think?
 
Was looking at the P-40F manual and saw a few numbers that bear on this. for instance take-off of our hypothetical fighter.

A clean P40-F at 7500lbs
...
At 9300lbs but clean it needs 13.3 minutes and 44 gallons of gas to get to 20,000ft.

Adding hundreds of pounds to 1000-1200hp fighters could affect take-off (can't use existing fields) and initial climb out to the extent you aren't going to get the range increase you might think?

Problem might be that you are using one of the heaviest V12 powered mid-war fighters as base.
We can start from Re.2001, for example. It carried 140 US gals of fuel on total weight of 3267 kg (7200 lbs). Extra 150 gals (if we aim for 300 gals total fuel; 50 gals of that being internal) is 900 lbs, plus weight of fuel tanks, racks and plumbing. 1200 lbs extra? remove two LMGs, suplant with two HMGs & ammo = 100 lbs extra? Adds up to 8500 take off weight.
Or, Spitfire III with wing tanks a-la Mk.VIII + rear fuselage tank as used on Spitfire Vs: 99 + 25 + 29 gals = 153 imp gals = 183 US gals. Drop tank of 90 imp gals = 110 US gals. All-up weight of Spit III (= with guns, ammo, fuel, pilot etc) was 7550 lbs; take off run of 250 yds - 750 ft? 200 US gals extra is 1200 lbs + plumbing and tanks themselves, so we're at 8800 lbs.
 
What I was trying to get at is disproportionate increase in take-off distances and times to altitude (and fuel used to get there) that is caused by a 24% increase in weight (7500lbs to 9300) or even a 9.5% increase in weight (8500-9300lbs) and that is with the most powerful engine in the group and using 100/130 fuel.
clean the increase in weight of 9.5% meant 12.8% more fuel used and 25% more time for the P-40F
With the drop tank (one) the same weight now means 30% more fuel and 65% more time.


for the engines involved it also helps to the take-off power and the climb power.


.........................................take-off...................climb......................power at 20K
Merlin III..........................880..................990/12,000ft.............................. 890
Merlin X: .......................1065................1035/2250ft..................................925
Merlin XII:.......................1175.............NP +9 2850rpm............................945
Merlin XX: ......................1280.............1125/9,500 MS............................1060 (similar for Mk.45)

DB 601A: ......................1100...............910-990.(30 min) ........................800
clones............................1175.................??????.............................................850?
DB 601N:........................1175..............1020-1050................................... 1020
DB 601E:.........................1375..............1000-`1040.................................. 1030/1130


V-1710-33:....................1040..................930................................................. 860 (similar with -39)
V-1710-39.....................1150..................1000................................................860?
1941:
V-1710 turbo: ..............1150.................1000..............................................1150
R-1830 and
R-1820 turbo: .............1200..................1000..............................................1200

Open to correction. Climb ratings are either 30 minute or continuous and are sea level through medium (in this case 10-15,000ft??) altitude.

Merlin III, X DB 601s (except N) are with 87 octane. American engines are with 100/100. later British engines are with 100/115-120 or 100/130 fuel.

why was the early P-47 (no drop tank) such a lousy escort? Because it burned 90 gallons of it's 305 gallons just getting to 25,000ft.

heavily loaded fighters are going to need big airfields and burn some of their extra fuel just getting to the desired altitudes.
Performance at altitude may be much poorer (or a greater difference) than comparing times to altitude might suggest.
 
What I was trying to get at is disproportionate increase in take-off distances and times to altitude (and fuel used to get there) that is caused by a 24% increase in weight (7500lbs to 9300) or even a 9.5% increase in weight (8500-9300lbs) and that is with the most powerful engine in the group and using 100/130 fuel.
clean the increase in weight of 9.5% meant 12.8% more fuel used and 25% more time for the P-40F
With the drop tank (one) the same weight now means 30% more fuel and 65% more time.

Weight, or wing loading, was a killer when it is about take off, the increase of take-off power was able to cancel that just by that or this percentage. We have Spitfire V with 1185 HP for take off, yet it can took off from aircraft carries when it was overloaded with fuel for ferrying.

for the engines involved it also helps to the take-off power and the climb power.
.........................................take-off...................climb......................power at 20K
Merlin III..........................880..................990/12,000ft.............................. 890
Merlin X: .......................1065................1035/2250ft..................................925
Merlin XII:.......................1175.............NP +9 2850rpm............................945
Merlin XX: ......................1280.............1125/9,500 MS............................1060 (similar for Mk.45)

DB 601A: ......................1100...............910-990.(30 min) ........................800
clones............................1175.................??????.............................................850?
DB 601N:........................1175..............1020-1050................................... 1020
DB 601E:.........................1375..............1000-`1040.................................. 1030/1130


V-1710-33:....................1040..................930................................................. 860 (similar with -39)
V-1710-39.....................1150..................1000................................................860?
1941:
V-1710 turbo: ..............1150.................1000..............................................1150
R-1830 and
R-1820 turbo: .............1200..................1000..............................................1200

Open to correction. Climb ratings are either 30 minute or continuous and are sea level through medium (in this case 10-15,000ft??) altitude.

Merlin III, X DB 601s (except N) are with 87 octane. American engines are with 100/100. later British engines are with 100/115-120 or 100/130 fuel.

On 100 oct fuel, Merlin X was good for ~1280 HP for take off (no jiggery-pokkery, manufacturers values).
Italian copy of DB 601A was supposedly good for 1050 PS at 4.5 km, vs. DB 601A (the one with better S/C) was good for 1020 PS at 4.5 km. At 20000 ft, the respective powers are perhaps 820 HP vs. 800?

heavily loaded fighters are going to need big airfields and burn some of their extra fuel just getting to the desired altitudes.
Performance at altitude may be much poorer (or a greater difference) than comparing times to altitude might suggest.

Fighter with plenty of fuel can switch to drop tanks at 10000 ft, thus not draining it's internal tanks too much.
 
-Wonder if someone can come up with a viable escort fighter on 1000-1200 HP (at 20000-15000 ft of altitude; historical engines only)
-Obviously, the time of interest would be the 1st years of the war (only for hypothetical fighters).

Depending what the vague "1st years" means, my choice would be:
Early P-51, but with the DB601 and 3xMG151/20
 
Depending what the vague "1st years" means, my choice would be:
Early P-51, but with the DB601 and 3xMG151/20

First 24 months, perhaps - until Sept 1st 1941.
That rules out P-51 as base due to being too late, and MG151/20 is around just last 3 months. We also have a ting of what to carve out the fuselage just aft the engine in order for engine cannon & ammo to fit, and make DB 601 not to mess with engine cannon operation as it was the case with DB 601A for most of it's life (or ever at all?).
 
Weight, or wing loading, was a killer when it is about take off, the increase of take-off power was able to cancel that just by that or this percentage. We have Spitfire V with 1185 HP for take off, yet it can took off from aircraft carries when it was overloaded with fuel for ferrying.

Well, you could get a P-40 off of a carrier deck to, it just had to be light and the carrier had to doing 25knots into whatever wind there was. If you could arrange your escort fighter fields so that
1. There was ALWAYS a 20-25mph wind blowing down the field.
2. There was a 50-60ft cliff at the end of the runway for the plane to drop into to trade altitude for speed instead of climbing 50ft over trees./buildings then you could use much smaller airfields. :)



On 100 oct fuel, Merlin X was good for ~1280 HP for take off (no jiggery-pokkery, manufacturers values).

Yes it could, but that brings us back to when you start the design, The British had annouced at the Paris Air show in Nov 1938 that they expected to get 1300hp from the Merlin VIII for take off on 100 octane, and 1145hp at 16,750ft in high gear on the Merlin X.
Italian copy of DB 601A was supposedly good for 1050 PS at 4.5 km, vs. DB 601A (the one with better S/C) was good for 1020 PS at 4.5 km. At 20000 ft, the respective powers are perhaps 820 HP vs. 800?



Fighter with plenty of fuel can switch to drop tanks at 10000 ft, thus not draining it's internal tanks too much.

They could switch at 5000ft or less, whatever it took to turn around and land back at the airfield should the engine quit when switching over.
Point was that while yes, you are extending the range, you are also burning up 5-10% of your expanded fuel capacity (however stored) just getting to operational altitude.

The Mustang had the power (and aerodynamics) to blast it's way to 25,000ft carrying a pair of 75 gallon drop tanks (330 gallons total) in 16 minutes and use 60 gallons from startup using military power.

Climb at 20,000ft or so is really affected by either power or weight.

Power for climb is the power left after you take out the power needed for straight and level flight at the altitude in question.

Just to illustrate the point lets say Plane X needs 200hp to move along 20-30mph faster than stalling (actually needs less power that right at stall speed) and at this height it has one of the 800hp engines, it has 600hp to devote to climb (low speed but high angle?) while if Plane X had a 1000hp engine it would have 800hp available for climb. a 33% increase in avialbel power vs the 25% increase the raw number gives us.

It is this "net" number that we need to use (or approximate) when figuring performance of our "loaded" escort fighters. Speed is not affected much by extra internal fuel but climb and turning ability is, not turning radius on it's own but the ability to turn and maintain altitude or turn and climb at the same time.
 
Yes it could, but that brings us back to when you start the design, The British had annouced at the Paris Air show in Nov 1938 that they expected to get 1300hp from the Merlin VIII for take off on 100 octane, and 1145hp at 16,750ft in high gear on the Merlin X.
Italian copy of DB 601A was supposedly good for 1050 PS at 4.5 km, vs. DB 601A (the one with better S/C) was good for 1020 PS at 4.5 km. At 20000 ft, the respective powers are perhaps 820 HP vs. 800?

I'd start the design of a long-range fighter when the 1st Merlin is available. The engine was, after all, capable to make the 10000 lb Battle fly. By that time, Germans don't even have Jumo 210 in production.
 
If you want a long range fighter then the Whirlwind would have been okay if the engines had a better high altitude performance or it could take Merlins without too many mods, so that leaves you the Gloster F9/37 which was powered by either Taurus or Peregrines. The advantage of the Gloster over the Whirlwind is that it has lots of wing area to support Merlins and extra fuel. The Germans have the Fw 187, the Americans the Lightning.
 
If you want a long range fighter then the Whirlwind would have been okay if the engines had a better high altitude performance or it could take Merlins without too many mods, so that leaves you the Gloster F9/37 which was powered by either Taurus or Peregrines. The advantage of the Gloster over the Whirlwind is that it has lots of wing area to support Merlins and extra fuel. The Germans have the Fw 187, the Americans the Lightning.
Much as I like the Whirlwind and think it got a bad deal, but it was never going to be a long range fighter. It was two small an airframe for two engines and enough fuel to fly long ranges.
flying 20-50 miles further than an early Spitfire is one thing, flying 300-400mile radius bomber escort missions is another thing altogether.
 
Again, you must be more specific. First flight of the prototype, first production , introduction to service, first combat, what ?

Service date, in case one wants to mix & match historical A/C and parts (engines, armament, hi-lift devices etc) together.
 
Service date, in case one wants to mix & match historical A/C and parts (engines, armament, hi-lift devices etc) together.

OK;
A6M2 fits the bill pretty much at is was.
But let's tune it a little bit:
- Engine: Two stage R-1830
- Armour: Seat and head armour plate, 10mm, armour glass in front
- Self sealing rubber bag tanks.
- Armament: 2xMG151/20 cowling guns.

Heavier, yes, but faster and much more survivable.
 
Made this comment on a earlier post about the Zero and Hayabusa ….
Both were structurally very strong planes.
They easier to Train in losing less pilots toward becoming a competent Fighter Pilots than US planes...
Both shooting down more allied aircraft that our historians give them credit for.

In every book I have read...
Japanese pilots did not have the accident rate US pilots (P40), German(Me109) and British( Spitfire) had especially landing.
The Japanese Radial seemed more reliable requiring little maintenance and looked easier to work on. (OF course Need more Information for proof)
Japanese logistics and living and field conditions were horrible compared to US.
So this was critical putting up a working Fighter.

One recent take historical away was that the Japanese Army and Navy did not collaborate and share its fuel stocks with each other.
The Navy used a better octane than the Army.

YET despite being overtaken by more Modern Allied Planes the Zero and Hayabusa improvement kept them dangerous!
 
If the Japanese had more powerful engines for the Zero then they wouldn't have designed the Zero.
 

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