P-40 Twin

[Ivan1GFP]

Ok, so back to Glen's original question:
I'd suggest looking at a P-61C's nacelles and wing ducting.
That should be the closest I can think of to the the P-47's cowling and engine.

At some point the designer has to make a decision as to whether this concept is just for looks or is supposed to be plausible. Without increasing wingspan, there isn't really any room for flaps on the trailing edge. It is even worse for the P-40.
Since I do these designs as 3D models, it is pretty easy to prototype something just to get an idea of the necessary planform for areas. I don't actually check the areas by eyeball; I wrote up a little program way back when my Son was still in High School which takes the vertices of a Wing or other polygon (think flap outline) and can calculate the area using Heron's Theorem. Son was doing something with the area of triangles and basically any polygon can be broken up into some number of triangles.

There is no reason the full induction system can't all fit in a nacelle. There is plenty of volume left over if there is no pilot or fuel tanks there and enough room for the entire main gear on each side as well.

Happy New Year Folks.

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[GrauGeist]

At some point the designer has to make a decision as to whether this concept is just for looks or is supposed to be plausible. Without increasing wingspan, there isn't really any room for flaps on the trailing edge. It is even worse for the P-40.
Since I do these designs as 3D models, it is pretty easy to prototype something just to get an idea of the necessary planform for areas. I don't actually check the areas by eyeball; I wrote up a little program way back when my Son was still in High School which takes the vertices of a Wing or other polygon (think flap outline) and can calculate the area using Heron's Theorem. Son was doing something with the area of triangles and basically any polygon can be broken up into some number of triangles.

There is no reason the full induction system can't all fit in a nacelle. There is plenty of volume left over if there is no pilot or fuel tanks there and enough room for the entire main gear on each side as well.

Happy New Year Folks.

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He just wants to make a for-fun, what-if twin engined P-47, FFS - not a flyable combat beast.

 

[Alex Smart]

I've been kicking around the idea of building this one for years, and I recently acquired a lot of 3 box-less 1/48th scale AMTech P-40F's for $20 so I thought now was the time. It will be a long term project so please bear with me.

Picture 1) There's been some discussion about this photo on the internet and it's rather a mystery. There's no record of a twin P-40 ever having been made and the only evidence of one is this photo. The serial belongs to a P-40C, but the rear fuselage obviously belongs to a later model, either a 'D', 'E', or short tail 'F'. The engines are Merlins, probably from an 'F', and something else I noticed was that there is no wing to fuselage fairing.
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Picture 2) This is a profile originally of a P-40F that I modified to depict the aircraft I intend to model. I'll be working under the pretense that the aircraft in the picture was a mock-up and what I'll be modeling is the production model.View attachment 244175 View attachment 244176

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One of the obvious weak points of the mock-up is side visibility. With those high mounted Merlins it would be like flying in a box, so in my production version the engines will be mounted lower, the centerline of the props even with the center of the wing. This isn't as much improvement as it would have been with the top of the engine even with the top of the wing, but that would have required the landing gear to be much too long for prop clearance.
I've also chosen to put a longer nose on it than what appears to be on the mock-up if the mock-up was fitted with a nose at all. If it was it was a very stubby one. I figure at least a couple more fifties than the standard P-40.
Also, to leave the landing gear in the original position as on the mockup I think is just silly with the nacelles right there, so I've moved them to that new position.
I chose to base it on the P-40F model for several reasons. First I think the longer tail that was introduced to handle the increased power of the Merlin and later Allison engines would be an absolute necessity with the twin engines, and second, I think if you were going to the trouble to increase the power of a P-40 like this you'd want the higher service ceiling of the Merlins.

So here goes. It may never have flown, bit it would have been on wicked looking machine.

Hello T Bolt,
Good to see this twin P-40 on the forum. It has been a few years since the first viewing.

As I recall it was a mock up built by ground staff of a P-40 Unit that was to be allotted the P-38.
So to familiarise the Units Pilots to handling a twin engined aircraft this mock up was assembled.
From memory it was only used to familiarise the pilot with the twin only ground taxiing.
There was no nose cone, just the flat(?) Area at the front where the original engine used to be, also the reason that there were no wing/fuselage fairings.

I forget now the name of the American aviation forum where the photo and details were first aired, perhaps one of this forum's members can recall it ?

All the very best
Happy New Year
Alex

 

[J4F-2]

Here's the finished pictures guys. The guns are bits of copper wire and the cannons are aluminum tube. I still intend to do this in 1/48th scale and still have the two AMTech P-40F's waiting to be chopped up, but it will be a little wile before I start on it. When I do I'll just continue on with this thread.View attachment 259009 View attachment 259010 View attachment 259011 View attachment 259012 View attachment 259013 View attachment 259014 View attachment 259016 View attachment 259017 View attachment 259018 View attachment 259019 View attachment 259020 View attachment 259021 View attachment 259022 View attachment 259023 View attachment 259024 View attachment 259025 View attachment 259026 View attachment 259027 View attachment 259029 View attachment 259030 View attachment 259031 View attachment 259032 View attachment 259033 View attachment 259034 View attachment 259035 View attachment 259036 View attachment 259037

Amazing build, Well Done !

 

[J4F-2]

Some pictures of the 1/72nd and 1/48th versions together. And lastly the magazine that started it all which has been up in my attic all these years.

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Another fantastic build, even better than the 1st one !

 

[T Bolt]

Thanks, that was the most extensive kitbash I have done to date

 

[Warbirdnutball]

Closer and closer to the finish

The prop assemblies painted

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One last shot of the gear legs with the wheels and brake lines installed and then glued on and sitting on the wheels

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This looks amazing. I am curious though. Would the landing gear support the weight? Most twin engines aircraft seems to have more intricate equipment. I could be wrong and if so I apologize.

 

[Warbirdnutball]

It's finally done and its been a long time coming from when I first started thinking about this project .
In the November 1995 issue of Scale Modeler Magazine there was an article about a conversion like this and I started thinking about doing it myself. Jump ahead five or six years when I acquired the two Heller kits to do it. Those kits sat in my stash waiting, being pulled down and looked at from time to time as I thought about starting the project, until I finally did in September 2013. By that time I had decided to it in 1/48th scale instead of the 1/72nd scale of the Heller kits, but thought it would be a good idea to start with the Heller kits to make sure I could do it before I went and cut up two I/48 AMT kits. The 1/72nd version took me six months to complete and I decided to take a break before starting the 1/48th version.
That break turned into five years when a little over a year ago I started cutting up the AMT kits.

Well here it is, 25 years from conception to finished model. That has got to be some king of record!

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Magnificent! Truly a work of art.

 

[GrauGeist]

This looks amazing. I am curious though. Would the landing gear support the weight? Most twin engines aircraft seems to have more intricate equipment. I could be wrong and if so I apologize.

The P-40 had fairly robust landing gear, which enabled it to operate under a variety of conditions.

The P-40 "twin" would have only had the additional weight of the second V-1710 and cowling, which would have been far less than the weight of a full warload for a P-40 in combat.

Plus the "twin" was primarily for ground training, so taxiing around wouldn't have put too much stress on the main gear.

 

[Warbirdnutball]

The P-40 had fairly robust landing gear, which enabled it to operate under a variety of conditions.

The P-40 "twin" would have only had the additional weight of the second V-1710 and cowling, which would have been far less than the weight of a full warload for a P-40 in combat.

Plus the "twin" was primarily for ground training, so taxiing around wouldn't have put too much stress on the main gear.

True, however the fuel supply would be increased as well or the double hawk would have very short legs. A lengthened fuselage as well to balance the new engine. I'm not saying that the landing gear would need much beefing up, but there would need to be some.

 

[T Bolt]

For that reason I fabracated new legs insted of using the stock P-40 legs.

 

[GrauGeist]

True, however the fuel supply would be increased as well or the double hawk would have very short legs. A lengthened fuselage as well to balance the new engine. I'm not saying that the landing gear would need much beefing up, but there would need to be some.

As far as I have ever seen, the P-40 twin never got airborn, it was relegated to static cockpit familiarization and ground rolls around the field's taxiways.

So additional fuel may not have been an issue, since the V-1710s weren't operated at full capacity.

The one thing I never heard about, was if there were any over heating issues during engine-on training.

 

[jetcal1]

Backtracking to the twin Thunderbolt? Give the design trends at Republic at the time? One could easily imagine a fuselage resembling the first P-84 with wings inspired by the XF-12, with some inspiration taken from the XP-72 and the XF-12 for the engine installation.
Never mind the minor details like landing gear design, fuel capacity, and other trivial concerns, it would make for a neat model.

 

[T Bolt]

I've been thinking about a twin engined Mustang lately and thought it might be better to be based on the F-82 rather than the P-51. Well yesterday I picked up a cheep, unboxed 1/48th scale Modelcraft F-82 I could cut-up to make it work.
I spent a few hours working on the drawing below based on an F-82 drawing. The longer length of the F-82 would help, and I kept part of the F-82's connecting wing between the fuselage and nacelles giving it a longer wingspan than the P-51. I also gave it tricycle landing gear.
The drawing below is a work in progress, but I think it will work. The only thing I'm not sure of is what I can use for the nacelles behind the engines. If I do get started on it I'll start a new thread for it.

 

[SaparotRob]

COOL!

 

[MIflyer]

Interesting! Note that it would not need that belly radiator, but would need some out on the nacelles.

That reminds me. I need to dig out that kitbashed "Last Ditch Terror Attacker" I made from one Hawk 1/48 Baka and two Hawk 1/48 V-1's. I was looking through a Squadron sale flyer on the train during my daily trip home from the Pentagon circa 1990 and dreamed that one up.

 

[T Bolt]

Don't know how I'd eliminate the fuselage mounted radiator and still retain the look of the Mustang, which is the whole point. If I put them on the nacelles there would be no room for the landing gear unless I moved then up right behind the prop, but then it would look like a P-40. I think I'll just say that the fuselage radiator is a now a "High Efficiently" one that takes care of both engines.

Here is a quick comparison between one based on an F-82 and one based on a P-51

 

[SaparotRob]

I had thought about the fuse radiator too.
Beer cooler.

 

[GrauGeist]

The fuselage on the P-82 concept combined with the nose and nacelles of the P-51 concept would look fantastic.

 

[Vic Balshaw]

An interesting concept and you could always put a couple of horn like coolers in the engine just like on the Bristol Mercury.