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So the reason was for this had to with the economic climate, the unwillingness of the manufacturer to design an engine with their own money, and the constant design changes?wuzak said:To get a sense of the slowness of development of the IV-1430, the Rolls-Royce PV-12/Merlin was started after the hyper program began, and was in series production and service when the first Continental V12 engine was run.
So they should have basically designed a single cylinder and then had the engine built around the cylinder specs?For the IV-1430 a single cylinder should have sufficed. Not sure if they did multi-cylinder development at all.
So the reason was for this had to with the economic climate, the unwillingness of the manufacturer to design an engine with their own money, and the constant design changes?
I get that, but I was under the impression that the reason this deal was hatched between the US Army and Continental (because you said so) was that they would not have agreed to designing the engine on their own money with US specifications outlined...Continental were acting as the Army's jobbing shop.
They made what the army asked, when the Army asked, no more and no less.
I thought for national security matters, you don't have to select a competitor?The Army could have put out a specification but the number of bidders or companies responding would have been small and mostly of the crackpot variety.
I'm honestly wondering if the Army made the decision to just be building the engine manufacturer, like they wanted to be nationalizing engine production. Kind of like producing all the bullets...In 1932 an agreement for the engineering and development of this cylinder and of the engine employing it was reached between the Army and the Continental Motor Company. . . . The company had earlier had an unimportant contract with the Army for a single-sleeve-valve liquid-cooled engine, which was dropped because of poor performance at the time the Hyper project was undertaken. . . . The Army not only had decided upon the basic principles and the size of the Hyper cylinder but also had laid down the main lines of the complete engine in which it was to be used, and the first two years of work were actually done in a special office set up by the company in Dayton to be near Wright Field.
The Navy had it's own aircraft factory if I recall. I'm surprised the US Army didn't do that too.The Departments of Navy and Army both maintained manufacturing and design facilities.
That's a good pointOne of the benefits of this was that both services had considerable in-house expertise, which has been lost since these facilities were largely closed.
The XB-15's wings were so thick you could walk through them
Race Planes: By the 1931, it would appear a speed of 407 was achieved;
Did that include the crawl space, or just the whole wing thickness?Walk is a bit of an exaggeration. This a 314 Clipper wing but it was only 3 ft shorter than the XB-15 wing.
So there was an assumption that a non-racer would have thicker wings to support itself from within?Notice the bracing struts. You can get away with a a thinner wing if you aren't depending on the the wing itself to handle all the bending loads,
It would appear that, at some point, they had concluded that a fighter could not carry an engine within its wings (at which point they went to an inverted-V), which makes me wonder how much thoughts they gave to this early on (the USAAC had some elements in it that were almost comically bomber-centric).Somebody may have known that thin wings had less drag. What was unknown was how much less drag (and at what speeds). This was complicated by the known fact that a thin wing of a given strength was heavier than a thick wing of of the same size and strength.
The racer had over 2200hp at sea level compared to the 880 om a Merlin II/III. They thought the struts/wires caused drag and a thicker wing without struts/wires would have less total drag.So there was an assumption that a non-racer would have thicker wings to support itself from within?
How tall was the O-1230? I ask because the Seversky P-35's wing was around 0.18:1 based on a drawing I have and that seems around 16-17 inches thick.
="Zipper730, post: 1479554, member: 67843"]
It was never going to fit in a single engine/single seat fighter wing.
Oh, never mind...="Zipper730, post: 1479554, member: 67843"]3ft less wing span. I would imagine that much of the interior wing structure as the same or similar.
So it was a faulty premise even back then? I'm looking at the PB-2A/P-30 and I'm also getting T/C figures of 20%, but even then the aircraft's only 30 feet long, and with the chord being what it is -- almost 128 inches just outside the fillet, and with 20.2% from that area that gives me 25.8" thickness, which is substantial and might even be able to fit inside. But that's almost at the root.It was never going to fit in a single engine/single seat fighter wing. The basic engine was fairly flat but the magnetos, intake manifold, supercharger and carb all added to the hight.
True, but that plane was huge and was only stressed for 5.1 ultimate and 3.4 normal. That said, the Beaufighter TFX was not much smaller (in length anyway), and could pull 8.5G at 25120, about 8.9-something at 24000 and 9.5 or so at around 22450 (basically with the torpedo off).It might not have done too bad in something the size of an Airacuda though.
It was based around the idea of reducing drag. I'm not sure what they knew about radiator design and reducing cooling drag.Why would anyone want to fit an engine for a single engine fighter in the wing?
It was based around the idea of reducing drag. I'm not sure what they knew about radiator design and reducing cooling drag.
Good point! From what I remember, they wanted the flat arrangement to reduce drag in bombers. Then they figured that the bombers wouldn't need more power than the engines would allow (I'm surprised they didn't just add more engines), and then figured -- hey we can use this on fighters -- wait we can't put this engine in a fighter wing.Which wing do you put your single engine in for a single engine fighter?
The top one?Well duh.
Which wing do you put your single engine in for a single engine fighter?
The engine was actually rather large. The one test bed aircraft went from this.I'm surprised they didn't just put a flat cylinder in the fighter's nose it'd probably allow a little bit of visibility to be improved, or something like that.