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That means you will be running a large diameter extremely high temperature pipe inside a large cooling shroud, which will still be very warm at least, inside the left side of the cockpit about where the engine flap and landing gear controls are so where are you going to put those rather essential components?
Would it be better than a Spitfire, bearing in mind its weight just as a normal P-51?
The original post clearly states "interceptor" if you are discussing photo recon carry huge amounts of fuel internally and lots of cameras like a Mosquito. All those external tanks on that P51 don't give a longer range they just allow it to fly so far it cant get back.Consider the long span, high altitude potential (pressurized cockpit needed!) and fuel tankage (range!), I think the "what if" P-51HA is a lot better than a Spitfire for reconnaissance (I didn´t buy the "interceptor" idea). But where to put the cameras? Rear fuselage? An underwing camera pod? The more I think about these problems, the more I like the Merlin option.
The original post clearly states "interceptor" if you are discussing photo recon carry huge amounts of fuel internally and lots of cameras like a Mosquito. All those external tanks on that P51 don't give a longer range they just allow it to fly so far it cant get back.
The P-51 was already 1 ton heavier than a Spitfire with the same engine, that is a lot of lift required at extreme altitudes, when it comes to long range recon those tanks on the outside throw away much of the P-51 superiority in aero dynamics and as I said could easily result in it flying to a place it couldn't get back from.Sorry for not making it clear that I was not going for the interceptor option. I think USAAF would ask for such interceptor only if they think the german and japanese high altitude planes (bombers and recconaissance) then in the development stage could have been a real threat. In this case the what if P-51HA wings would be armed and carry a lot less fuel for a shorter range but high altitude capability.
In either case, four external tanks are counter-productive.
That Allison in the later F-82 is already a high altitude engine plus it has about 2250 hp. They had second stage mechanical supercharging plus water injection which was rarely ever used.
40,000 feet. With the P-82B its service ceiling was suppose to be 41,600 feet with Merlin's and the "G" was 38,900 feet with the pickle and the Allison's. I had thought that Allison engine in the F-82 was rated at 1500hp-1600hp for years because of the books of Bowers & Wagner. Then in 1981 I got to hear an F-82 pilot who said "that's BS!" He also implied that the Allison version was faster than the Merlin.
That Allison in the later F-82 is already a high altitude engine plus it has about 2250 hp. They had second stage mechanical supercharging plus water injection which was rarely ever used.
There is no way that the V-1710s had 2,250hp @ 40,000ft. The only way that would happen is with a very high altitude turbocharger, which I don't believe was made in the B-series turbo (there was in the C-series for the P-47).
The 2,250hp was achieved with increased boost, which has the effect of lowering the altitude at which the peak is produced.
From your previous post:
The 2,250hp was only available with ADI.
Not sure if the V-1710s in the P-82 had intercoolers - most 2 stage Allisons did not.
This might be a crazy idea, but add a 3rd gear to the supercharger of the merlin.
The two stage Merlins were designated as RM.#SM.
I know all about the Packard Merlin -3/-9 and -7.
When the Griffon went to 3 speed supercharging, the suffix became SML - fully supercharged, medium supercharged and low supercharged. The third gear was for low altitude performance.
Didn't know that. Thanks for the info.