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Not quiteSo basically, we're reinventing the P-47
The one of the biggest cause of losses for B17 and 24s were engine fires so in the spring of 1943 the USAAF removed the nacelle extinguishers as part of a weight reduction program. in December 1943 the B24s got theirs back while the B17 waited until the summer of 1944. The other feature I believe was deleted was the emergency oil back up tank for the propeller feathering system. It was rare for a bomber to make it back with an unfeathered prop. With thinking like that for big expensive bombers with big expensive crews I think the P38 pilots should have been grateful that they at least got an engine driven generator instead of a wind driven one.Ya know, it's amazing the thought process when decisions like this are made. I would think the generator would weigh about 40 pounds and cost about $150.00 in 1941 dollars. When you're trying to get the maximum amount of performance out of an aircraft, you'll have folks looking at doing anything to reduce weight. 40 pounds can be huge, especially when developing a fighter. Multiply that $150 generator cost by say 1000 units and you're looking at $150,000 in 1941 dollars which equates to $2.7 million in today's dollars. During a time when you're trying to build a high performance aircraft almost by committee and having to deal with a budget office that is still watching depression era dollars, I could see how this decision could be made. It would take operational experience as well as open purse strings to rectify this.
The R-2600 was never built for a motor-cannon through the hub (that I'm aware of) and the 37mm cannot be synchronized so the wing roots are out.
Well, this might have done the trick. Same time frame as P-38.
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A no-nonsense fighter with two non-turbo* V-1710s in 'classic' layout (ie. along the lines of Whirlwind, Type 327, Fw-187 and later DH Hornet) might've been a valuable asset. We'd probably have 370+ mph at 15000 ft even with the -33 engines if the aircraft's size is kept modest, at least when looking at what Ro.58 or Whirly were capable for.
(P-38D and E were doing ~375 mph, but at 20000 ft)
*yes, USAAC/AAF was hell bent on the idea that new fighters have to have turbochargers
There is going to be a great amount of difficulty getting a motor-cannon through the hub on an R-2600, or any other radial, for that matter, unless the reduction gearbox is remotely mounted (like the P-39).
Here's my attempt. Although the trouble is that CP.608 specifically called for a Twin-Engine interceptor so this would have to be in response to 609 (which led to the P-39). The other roadblock I'm running into is getting the proper armament fitted. I just can't find a way to fit 20mms much less a 37mm. The R-2600 was never built for a motor-cannon through the hub (that I'm aware of) and the 37mm cannot be synchronized so the wing roots are out.
So basically, we're reinventing the P-47
The only radial engined fighter that had a nose-cannon, that I can think of, is the Piaggio P.119 - and it was able to mount a 20mm cannon in the nose, because the radial engine was mounted mid-ship (a la P-39).
By virtue of a radial engine's design, there is literally no way to mount a motor cannon in it's centerline.
Something less than a P-47. But more than the P-43. As I was drawing it I certainly saw the resemblance—but something else was creeping in there too as I was trying to find clever packaging solutions: this almost seems as American FW-190.So basically, we're reinventing the P-47
Yes, which is why I ruled it out.There is going to be a great amount of difficulty getting a motor-cannon through the hub on an R-2600, or any other radial, for that matter, unless the reduction gearbox is remotely mounted (like the P-39).
The 1600hp R-2600 was rated for 1600hp at 1,000ft on 91 octane fuel and 1,500ft on 100 octane fuel in low gear.I may try a conventional twin R-2600 design though.
The Bell XF-52/59 was not all that unreasonable as a design, as the Swedes had a comparable design with the SAAB J-21.
Which, by the way, transitioned from a piston-powered type, to a jet-powered type (J-21R).
The problem the the USAAC's proposal, was timing. At that point in time, they were wanting an aircraft to fill a role that current engines were hard-pressed to deliver. This is why many air forces were exploring twin engined fighters (true fighters, not "heavy fighters") like SNCASE's SE.100, Fokker's G.I, Focke-Wulf's Fw187 and Grumman's XF5F/XP-50.
Being a single-seater, I've always felt the P-38 fits into the fighter category perfectly. It is perhaps one of the largest of the twin-engined fighters, but it delivered on the USAAC's request for a twin-engine interceptor, and then some.Out of curiosity only, do you reckon the P-38 a "fighter" or a "heavy fighter"?
The 1600hp R-2600 was rated for 1600hp at 1,000ft on 91 octane fuel and 1,500ft on 100 octane fuel in low gear.
In high gear the engine was good for 1400hp at 10,000ft on 91 octane fuel and 11,500ft on 100 octane fuel.
A R-2600 was the same diameter as an R-3350.
The R-2600 doesn't seem like a good candidate for a fighter engine, either single or twin.
Curtiss records show 9 (?) two stage R-2600-10 engines built between 5/41 and 5/42.Even the 1750 HP and the later 1900 HP versions, in order to be competitive against the axis best.
It is/was probably too bad that the 2-stage R-2600 was a bit late in coming (even if it was much earlier than the 2-stage V-1710); it was also 'Navy engine', that can complicate things for the Army before Pearl Harbor.
Should be able to switch and it should switch, just a soon as possible.A fighter designed around a R-2600 should be able to switch to the R-2800...
Could the P-38 have been built as a conventional twin, with turbocharged V-1710s, but with the turbochargers mounted in the fuselage, similar to what was proposed for the Curtiss XP-71?
Would such an arrangement lose more due to complexity than it would gain?
That's a lot of ducting. Wouldn't that requirement some enlargement to the design?
Not sure. It depends on how bigsg the fuselage is, I guess.
It is a lot of ducting, but, perhaps, not much more than the actual P-38.