P-36 with inline engine

[KJ_Lesnick]

While I like the P-36 because it had a light wing-loading and was highly maneuverable (it was probably quite rugged -- at least the P-40 was), it was kind of slow owing to at least some of the following

• Radial cowl (which was common for the era) produced high airframe cooling drag due to the primitive cowling configuration (later cowling designs would be longer, have more of a bell-mouth, more of a bullet-shaped spinner)
  
• Lacked supercharging, reducing high-altitude performance
  
• Wings might have been too thick * (See footnote 1)
  

w
I'm wondering if you had a P-36 with the following

• A V-1710 ** (See footnote 2)
  
• An advanced radiator based on the NACA cowling principle *** (see footnote 3)
  
• A supercharger
  
• If necessary, thinner wings (which could be made larger if need be to produce necessary lift)
  
• 2 x 12.7mm guns instead of 1 x 7.62mm & 1 x 12.7mm gun in the nose
  
• Possibly 2 x 7.62 or 12.7mm guns mounted in the wings
  

..
As I see it you could easily be looking at an "American Spitfire": It would have greater overall speed and horsepower, greater climb-performance (particularly at altitudes in excess of 10,000 feet), and a higher top-speed due to lower drag.  It would also have more firepower.


Footnotes:

1: Regarding the P-36 Wing Thickness

• I'm uncertain if the P-36's wings were thicker than the P-40.  If they were the same thickness there would be no issue
  

..
2: Regarding the V-1710

• I'm aware the V-1710 hadn't completed it's bench tests until the late 1930
  
• This was due to the fact that the design teams were too small due to poor demand for the engines
  
• The design of the V-1710 started as early as 1929
  
• If there were a greater demand, the engine would have been ready earlier almost certainly
  

..
3: Regarding the Radiator Concept

• The NACA cowling worked by
  
• Increasing the mass/volume of airflow through the cowling
  
• Adjusting the velocity of the airflow through the cowling to maintain cooling while simultaneously increasing pressure so as to use the heat from the cylinders to produce a thrusting effect
  
• Accelerating the flow aft of the engine to maximize the thrusting effect
  
• The thrust is often negative related to the drag of the assembly, but it still served a valuable function in reducing the drag of cooling itself off
  
• This same principle could be applied to a radiator
  
• The effect is the same as the meredith effect but produced using earlier knowledge to do it
  

..
What do you think?

[eatthis]

i think get it done 

[rickshaw]

The P-40 is a P-36 with an inline engine, Kendra.

[wuzak]

The P-40 is a P-36 with an inline engine, Kendra.

As was the X/YP-37.

The concept here is interesting, if mainly for the annular radiator.

If the radiator and engine are built as part of an engine quick change module existing P-36s may be able to be converted easily, as well as new build models. The only problem is if there are issues with stability and change of CoG.

[KJ_Lesnick]

The P-40 is a P-36 with an inline engine, Kendra.

Then why is it so much heavier?  AFAIK even the initial P-40 was heavier than the P-36A

[wuzak]

The P-40 is a P-36 with an inline engine, Kendra.

Then why is it so much heavier?  AFAIK even the initial P-40 was heavier than the P-36A

Heavier engine.
Extra cooling system.
Extra equipment.
Extra guns and ammo.

[rickshaw]

The P-40 is a P-36 with an inline engine, Kendra.

Then why is it so much heavier?  AFAIK even the initial P-40 was heavier than the P-36A

Perhaps because the engine and its associated cooling systems are significantly heavier than a radial engine?
Then there is armour, self-sealing fuel tanks, extra equipment such as radios, etc?
Then there is the extra guns, more ammunition, etc?

[McGreig]

The XP-40 was created in 1938 by installing a V-1710-19 on P-36A airframe 38-010. The maximum speed was 342mph at 12,200 feet. Initial production P-40s had a V-1710-33 and could reach 357mph at 14,300. But they weren't really suitable for air combat having no armour, no self sealing tanks and only two machine guns. Armour, self sealing tanks and four wing mounted guns were added to British P-40s but the added weight reduced the speed. (Data from Bill Norton's "US Experimental & Prototype Aircraft - Fighters 1939 - 1945")

In contrast, a fully equipped Battle of Britain period Mk-I Spitfire, with an eight gun wing, had a maximum speed of 353mph at 20,000 feet.

There is always the danger, with hindsight, of assuming that things had to work out the way they did, and I know that the P-40 development was hampered by its being thought of by the USAAF as a second string aircraft (the Merlin-engined P-40F could do 364mph at 20,000 feet and turbosuperchargers and cannon armament might have made a big difference) but I really don't think that producing an "American Spitfire" with the P-36 as a starting point would have been feasible.

What you actually got with the P-40 – in the opinion of the Desert Air Force and the Russians – was a better Hurricane.

[Father Ennis]

From something I recently read, the P-36 was intended to be a lower tech and cheaper aircraft for export sales .  If you put all that on it you defeat the purpose it was used for. Not to mention it wouldn't be a P-36 anymore.

[KJ_Lesnick]

Everybody

Firstly
I did some checking here and the XP-40 weighed roughly as much as the P-36 and it's armament was 2 x 0.50 cal like I was looking for.  So if the P-36 was designed this way it would work out pretty nice.

Secondly
Was a single-stage supercharger included in the XP-40 or was that added later?

Lastly
Was the P-36 designed to be a low-tech export fighter?  Who did we export it to?

[pyro-manic]

Come on, Kendra - that information is very easily available. Ten seconds on Wikipedia will give you the answers.

[PR19_Kit]

Lastly
Was the P-36 designed to be a low-tech export fighter?  Who did we export it to?

The Armee de l'Air amongst others, but the aircraft never got there in time and were impressed into RAF service. That's been mentioned on here more than once in recent months.

[wuzak]

Secondly
Was a single-stage supercharger included in the XP-40 or was that added later?

It was part of the Allison V-1710. Only V-1710s for airships (GV-1710A) and non-aviation uses did without the supercharger.

[McGreig]

The Armee de l'Air amongst others, but the aircraft never got there in time and were impressed into RAF service.

Well, the French did take delivery of 316 of what they designated the Curtiss H-75 before the German victory and they accounted for approximately 1/4 of all French air-to-air kills in the 1939-40 period (and 44 of the captured aircraft were subsequently sold by the Germans to Finland).

Come on, Kendra -that information is very easily available. Ten seconds on Wikipedia will give you the answers.

I have to say that I agree with this - Wikipedia has a comprehensive article with, amongst other things, details of all users.

[KJ_Lesnick]

pyro-manic

It did say it was exported to France and Finland but it didn't say that it was specifically designed to be low-tech and for export


PR19_Kit

We would not have sold an aircraft with a supercharger or turbocharger to a foreign country correct?


wuzak

Thank you for your reply.  Out of curiosity, when would the V-1710 have been available if there had been a moderate/high demand for them (meaning larger design team)