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wuzak

Captain
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Jun 5, 2011
Hobart Tasmania
From a caption in America's Hundred Thousand of a picture of the XP-40:

The same prototype airplane getting a little closer to production configuation with coolant radiator moved forward, according to Project Engineer Don Berlin because the Curtiss Wright Sales Dept. persuaded management it shoudl be forward. In any case, the XP-40 won the January 1939 pursuit competition and was ordered into production.

You would think that a decision like that would be based on sound engineering reasons. The Tornado prototype, for example, had its radiator under the fuselage like the Hurrican before it. But it was found to not work very well, so it was moved forward.

But to be moved for marketing reasons?

XP-40 with belly radiator
535x292xCurtiss-XP40-38-10.jpg.pagespeed.ic.D7cF9k5BGi.jpg


With radiator forward
mystery0341.jpg
 
In it's original form the XP-40 had trouble breaking 300mph. Maybe the marketing dept wanted the engineering dept to try something, anything to get the v-12 powered version to go faster than the radial engine P-36 :)

That would seem a logical engineering reason for the change.
 
The switch from the belly radiator to the 'beard' radiator is covered in the 'Vee's for victory', pg. 94. Only coolant radiator was relocated there - the oil coolers are relocated from 'belly' position into the, now over-sized, wing fairings. Such a configuration cut the radiators-related drag by some 45%. The radiator-related drag was now just 5% of the total airplane drag.
The final XP-40 featured two coolant radiators and one oil radiator mounted under engine, a trademark of the P-40 family.
 
In it's original form the XP-40 had trouble breaking 300mph. Maybe the marketing dept wanted the engineering dept to try something, anything to get the v-12 powered version to go faster than the radial engine P-36 :)

With all the lumps, bumps and gun barrels its not surprising it was slow. Its surprising it was as fast as it was :lol:
 
Francis Dean passed away in 2001. However, in his book Curtiss Fighter Aircraft (2007) he states on page 258 referring to the XP-40:

"The initial prototype configuration had the radiator for the V-1710 beneath the fuselage aft of the wing... the configuration was modified after tests at NACA Langley showed cooling drag was less with a radiator located up front under the engine. In addition, the far aft radiator was particularly sensitive to foreign object damage, and involved long vulnerable coolant lines to and from the engine."

I cannot explain the discrepancy, but the later work seems much more reasonable regarding why the radiator was moved.
 
It was moved to improve things, not for marketing. Marketing well MAY have asked for it, I don't know, but the actual change would have been for improvement, not for looks.
 

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