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- #161
Wild_Bill_Kelso
Senior Master Sergeant
- 3,231
- Mar 18, 2022
That doesn't make a whole lot of sense.
It does, but you are arguing for the sake of arguing.
A P-40K used 8.80 gears. It had the -73 engine. Yes it will give you 1325 hp for take off instead of 1150hp of the -39 in the P-40E.
The difference in the two engines was the -39 gave you 1150hp at 11,700ft while the -73 gave you 1150hp at 12,000ft (how good are your spark plugs or how clean are your backfire screens).
The -73 engine could NOT MAKE any more power at any altitude than the -39 engine could. Due to it's stronger construction they allowed the -73 to make more power down low, like for take-off or when the plane was low enough that the supercharger could make more than the 56in of boost the -39 was limited to to. Now to get to that power at 60in of pressure you have to be flying several thousand feet lower than the the plane with the -39 engine is flying making 56in of pressure.
Not that much lower. But the part you are missing (intentionally or otherwise) is that, depending on the mission, the DAF often flew at very low altitudes. 5-6000 feet wasn't unusual. I am not, however, insisting that his Kittyhawk III from the anecdotes was a P-40K, since I don't actually know, and neither do you. I know you like the P-40M better, but that was not apparently what pilots in the field thought.
I can cite you some examples of how low they were flying because this too was an issue - one which the Germans heavily criticized the British for, but which many British and Commonwealth pilots routinely acknowledged.
We can argue about exactly which altitude that is according to how much you have Ram but that is basically it. The -73 engine will not give you any more power more than around 6000ft or so (No RAM Is 4300ft) than the -39 engine. Now in the story Officer Gibbes uses his superior power to leave the other Allied pilots behind and overtake the German planes that were flying above them and does so in such a way that his squadron mates are no longer in range or able to engage the enemy so how long did this take or what distance was involved?
Now if he was flying a P-40M (Kittyhawk III) with a -81 engine he would have several hundred more hp at around 9,000ft to 11,000 than his squadron mates and the story would make very good sense. Closer to 6-7,000ft his advantage over his squadron mates would get smaller and finally disappear. Over 11,000ft hew would still have an advantage although also getting smaller but not disappearing.
Again, we don't know, but the other fighters he was with were most likely Kittyhawk Mk II, i.e. Merlin XX engines, and there weren't too many altitude bands that a P-40M was making more power than they were. Maybe right between gears?
The point I was making is that they did have extra power available from some of those engines, and it clearly wasn't down at sea level.
Again, I don't know precisely because they rarely mention what RPM or precise throttle settings they were using in pilot interviews and so on, (partly because the interviewers wouldn't usually know what that even meant). They do say they picked up speed as they got into enemy territory. If they can get up to 300mph + at 38" Hg or 42" Hg, I think that is probably in the ballpark of what they were looking for. I don't think the 15 minute limit for military power was strictly followed in the combat areas though, though I suspect it was in rear area training areas. The 'military power' rating changed in the manuals as the war progressed, just as the WEP rating did.The story doesn't say he dove on the enemy planes and used superior power at low attitude to overtake the German planes.
So we are both guessing.
I have shown you that running at 2600rpm is only worth about 20mph over running at 3000rpm. You have seen that the manuals only want to you use the 3000rpm limit for 15 minutes (at best, some manuals say 5 minutes on the early engines)
Now increasing power to 2600rpm from an unknow setting was certainly easy enough to do. A P-40 could cruise at from 1800rpm or under up to 2600rpm. Speed could go from 183 IAS (216mph true) at 9000ft at 1800rpm to 261 IAS at 2600rpm (308mph true) so there was certainly more than enough ability to increase power prior to contact without going to military power.
Now if you are going down to bomb/strafe you do want the engine to operating at 3000rpm before contact. It you have a number of minutes to go at altitude before you are in the target area or you are flying cover for other aircraft (A-20 or Baltimore strike?) perhaps you don't want to be at Military power before you see enemy aircraft.
Some strange accounting going on there, except that the Bearcat had zero impact on the war, never got into combat.
Ok I'll spell it out a biut more clearly. Raw production numbers do not reflect significance in the war. Sometimes it did - they produced a hell of a lot of Spitfires, Bf 109s, Il-2s, P-51s, A6Ms etc., but sometimes it really didn't. Many types (particularly Allied types but Axis too) kept being produced even though they directly contributed very little, if anything, to the war. Service as a target tug was no doubt needed, but it was not on the same level of importance as a fighter that can and did shoot down enemy aircraft or a bomber that destroys enemy ships or tanks. Conversely, some types only produced in quite small numbers were still very important in the war because they were involved in the fighting during pivotal moments in a particular theater of the war. In some cases the newer fighter which was more widely produced was a better airplane. A Fairey Firefly is objectively a better figghter than a Macchi MC 200 - faster, better range, more heavily armed. But it wasn't in action early enough or in the right areas to have a major impact on the outcome of the war.
I know this is going to open a can of worms, but since you are being deliberately obstinate about this, let me be a bit cheeky too and give you some more obvious examples of my already very obvious point about Spit 1 vs. Spit V.
Needless to say, some later types may have still been effective and still did have an effect, but it just didn't matter as much because the tide of the war had already turned. A good example of this is the SBD vs. the SB2C. They made many more Helldivers, but the SBD was actually more important because of when it was in action (and how soon it was ready to fight effectively).
Brewster Buccaneer bomber - 771 produced
Martin Maryland bomber - 450 produced
Which bomber was more important for the war effort?
Douglas SBD Dauntless - 5936 produced
Curtiss SB2C Helldiver - 7140 produced
Which of the two was more important to the outcome of WW2 in general and the Pacific War in particular? Which type played a more pivotal role?
Bell P-63 Kingcobra fighter - 3303 produced
Macchi C.202 fighter - 1150 produced
Which of these two fighters shot down more enemy aircraft?
Fairey Battle bomber - 2201 produced
Aichi D3A bomber - 1405 produced (D3A1 and D3A2)
Which type caused more damage to the enemy during the war? Which type destroyed more militarily significant targets?
Fairey Barracuda torpedo bomber - 2602 produced
B5N "Kate" torpedo bomber - 1149 produced
Which type sunk more ships? Which type had more direct effect on the war?
Handley Page Hampden bomber - 1430 produced
Mitsubishi G3M bomber - 1048 produced
Which bomber type had more impact on the war? Which type destroyed more militarily significant targets? Which type sunk more ships?
Fairey Firefly - 1702 produced (through 1955)
Macchi C.200 Saetta - 1151 produced
Which of these fighters shot down more enemy aircraft?