1st pics +++ 1:72 Kyushu J7W3 ‘Shinden-Kai’, 343th Kokutai/301st Hikotai, IJN, 1946

[Dizzyfugu]

Mojo is highly limited at the moment (health, private issues, job... ), but I keep building things... like this project here, the Kyushu J7W3 'Shinden-Kai'!


This project is a personal but somewhat history-based interpretation of what could have been, inspired by the J7W2 model/conversion that Hasegawa offers for its propeller-driven J7W Shinden kit, turning the latter (outwardly) into a jet-powered version. As a framework and nmore detailed in the background that will follow some day: the J7W was originally envisioned as a jet-powered interceptor, but at a time when no suitable engine was available or even on Japanese drawing boards yet. So it was – as an interim solution – modified to accept a radial engine with a pusher propeller, but with the perspective to switch again to a jet powerplant later. Over time the Ne-20 jet engine was developed, which was a simplified adaptation of the German BMW 003 – an axial design and rather slim. But it was experimental at best and not very powerful or reliable. It was used and flown on the Nakajima J9N Kikka, though, but even with two of these engines the aircraft was rather underpowered and far from an effective fighter airplane, let alone a fast interceptor .
When you then take a look at Hasegawa's conversion offer (which only consists of a different end plate with a nozzle cone instead of the prop) for a J7W2 jet version of the Shinden, it's bullsh!t because a) a single indigenous jet engine like the Ne-20 and even its more powerful derivatives would never have had enough power to let the J7W airframe perform like an interceptor, let alone fly at all, and b) the potential engine size/shape, which would rather reflect a centrifugal engine with a much bigger diameter. The shape and size of the air intakes would also leave some doubts. Another factor that speaks against the Hasegawa "proposal" is the fact that there was and is apparently no reliable design sketch or layout for a re-jet-engined Shinden.

This would not stop an ambitious model kit builder like me to try a personal interpretation, and effectively one that is more plausible than Hasegawa's own rather lazy attempt. This eventually led to "my" J7W3, which took some inspiration from the very good and exhaustive description of the J7W in Edwin D. Myer's book "Japanese Secret Projects (1)". It discusses the potential engine options – which were all axial flow powerplants – and also suggests that there would have been some considerable hardware changes to the J7W airframe, like a modified tail section, a lowered/simplified landing gear, and therewith also different fins.

The basis became a standard Hasegawa J7W – and I had actually procured resin copies of the company's own J7W2 conversion parts. However, I made considerable conceptual changes. The central difference was the decision to mount a pair of axial flow engines in the real hull, and I had resin upgrade parts for the twin J47 gondolas' rear end for Hasegawa's 1:72 B-47 kit in The Stash™. One of these was implanted into the J7W's slightly shortened tail/engine bay, adding length so that the aircraft's center of gravity might be kept. Being much wider and flatter than the original radial engine I decided to add bigger air intakes, too, and to delete the original "slits" behind the cockpit. These were sanded away and replaced with the intakes from an Italeri BAe Hawk trainer, mounted relatively low in front of the wing's leading edge. They look a bit modern (esp. because of their boundary layer gaps to the fuselage) but were simply perfect in size and shape. The ducts connecting the new intakes and the side-by-side engines were then sculpted with 2C putty and PSRed into the rest of the hull.


1:72 Kyushu J7W3 'Shinden-Kai'; aircraft "(A-343-)15", 343th Kokutai/301st Hikotai, Imperial Japanese Navy, piloted by CPO Yishida Masaoka; Matsuyama AB (Shikoku/Takanawa peninsula, Japan), early 1946 (Whif/modified Hasegawa kit) - WiP by Dizzyfugu, on Flickr


1:72 Kyushu J7W3 'Shinden-Kai'; aircraft "(A-343-)15", 343th Kokutai/301st Hikotai, Imperial Japanese Navy, piloted by CPO Yishida Masaoka; Matsuyama AB (Shikoku/Takanawa peninsula, Japan), early 1946 (Whif/modified Hasegawa kit) - WiP by Dizzyfugu, on Flickr


1:72 Kyushu J7W3 'Shinden-Kai'; aircraft "(A-343-)15", 343th Kokutai/301st Hikotai, Imperial Japanese Navy, piloted by CPO Yishida Masaoka; Matsuyama AB (Shikoku/Takanawa peninsula, Japan), early 1946 (Whif/modified Hasegawa kit) - WiP by Dizzyfugu, on Flickr


1:72 Kyushu J7W3 'Shinden-Kai'; aircraft "(A-343-)15", 343th Kokutai/301st Hikotai, Imperial Japanese Navy, piloted by CPO Yishida Masaoka; Matsuyama AB (Shikoku/Takanawa peninsula, Japan), early 1946 (Whif/modified Hasegawa kit) - WiP by Dizzyfugu, on Flickr


1:72 Kyushu J7W3 'Shinden-Kai'; aircraft "(A-343-)15", 343th Kokutai/301st Hikotai, Imperial Japanese Navy, piloted by CPO Yishida Masaoka; Matsuyama AB (Shikoku/Takanawa peninsula, Japan), early 1946 (Whif/modified Hasegawa kit) - WiP by Dizzyfugu, on Flickr

The cockpit was taken OOB, but I decided to modify the canards and give them more shape. I initially experimented with swept surfaces, but that did not look plausible and so I "just" mounted elevators from an Intech P-51 kit. Another mod was made to the landing gear: while the OOB struts and wheels were used, all parts were shortened and the respective wells were reduced in length/size accordingly, what moved the front leg forward and the main landing gear inwards, reducing track width. With less ground clearance and for a different look I also replaced the fins on the wings' trailing edge – not an easy task, but I eventually found a pair of vintage elevators from an Airfix 1:72 F-86D kit, which were slightly modified and now occupy the original fins' places. They are taller now, have less depth, and the lower section under the wings was dramatically shortened, too. That shape was inspired by an illustration in Edwin D. Myer's book, and it looks quite plausible.
Another small mod was the replacement of the molded gun barrels with bits from hollow steel needles.


1:72 Kyushu J7W3 'Shinden-Kai'; aircraft "(A-343-)15", 343th Kokutai/301st Hikotai, Imperial Japanese Navy, piloted by CPO Yishida Masaoka; Matsuyama AB (Shikoku/Takanawa peninsula, Japan), early 1946 (Whif/modified Hasegawa kit) - WiP by Dizzyfugu, on Flickr


1:72 Kyushu J7W3 'Shinden-Kai'; aircraft "(A-343-)15", 343th Kokutai/301st Hikotai, Imperial Japanese Navy, piloted by CPO Yishida Masaoka; Matsuyama AB (Shikoku/Takanawa peninsula, Japan), early 1946 (Whif/modified Hasegawa kit) - WiP by Dizzyfugu, on Flickr

More coming soon...

[Gondor]

Nice upgrade to the Shinden 

Gondor

[PR19_Kit]

That's looking very good Thomas, specially the B-47-ish exhausts!

They're right in the time scale with the sculptured ducts and the central fairing.   

[zenrat]

Looking good Dizz.

[Dizzyfugu]

Thank you. 

[Stan in YUL]

Very interesting concept - keep cooking!

Stan

[Dizzyfugu]

More to show...

Painting and markings:
I considered a lot of potential livery options, including a bare metal finish, an improvised camouflage over that, or even highly exotic or speculative schemes (e.g. in all-over IJN grey-green or a very pale grey). In the end I settled for a simple/conservative IJN green/grey livery for land-based aircraft. Boring, yes, but the aircraft itself was already so exotic that I would keep the looks more standard (and therefor convincing).
However, I built the paint up so that aluminum would shine through here and there, and I painted upper surface areas in different shades of dark green (including ModelMaster's IJN Dark Green and Humbrol 2, 195 and 239). The underside was painted with Humbrol 40 (Light Gull Grey), and the low waterline became quite wavy.


1:72 Kyushu J7W3 'Shinden-Kai'; aircraft "(A-343-)15", 343th Kokutai/301st Hikotai, Imperial Japanese Navy, piloted by CPO Yishida Masaoka; Matsuyama AB (Shikoku/Takanawa peninsula, Japan), early 1946 (Whif/modified Hasegawa kit) - WiP by Dizzyfugu, on Flickr


1:72 Kyushu J7W3 'Shinden-Kai'; aircraft "(A-343-)15", 343th Kokutai/301st Hikotai, Imperial Japanese Navy, piloted by CPO Yishida Masaoka; Matsuyama AB (Shikoku/Takanawa peninsula, Japan), early 1946 (Whif/modified Hasegawa kit) - WiP by Dizzyfugu, on Flickr

The cockpit tub was painted in a yellowish green (a mix of Humbrol 63 and 226) while the landing gear wells were initially painted with aluminum and received a coat with translucent bright blue lacquer, simulating aodake iro. The landing gear struts became glossy black.

The model received a light black ink washing, thorough post-panel shading in various mixed shades of dark green on the upper surfaces, and dry-brushing with silver to simulate flakes paint here and there. The engine fainings were painted with Revell 91 (Iron metallic) and treated with graphite to provide them with a more metallic/burnt shine.


1:72 Kyushu J7W3 'Shinden-Kai'; aircraft "(A-343-)15", 343th Kokutai/301st Hikotai, Imperial Japanese Navy, piloted by CPO Yishida Masaoka; Matsuyama AB (Shikoku/Takanawa peninsula, Japan), early 1946 (Whif/modified Hasegawa kit) - WiP by Dizzyfugu, on Flickr


1:72 Kyushu J7W3 'Shinden-Kai'; aircraft "(A-343-)15", 343th Kokutai/301st Hikotai, Imperial Japanese Navy, piloted by CPO Yishida Masaoka; Matsuyama AB (Shikoku/Takanawa peninsula, Japan), early 1946 (Whif/modified Hasegawa kit) - WiP by Dizzyfugu, on Flickr


1:72 Kyushu J7W3 'Shinden-Kai'; aircraft "(A-343-)15", 343th Kokutai/301st Hikotai, Imperial Japanese Navy, piloted by CPO Yishida Masaoka; Matsuyama AB (Shikoku/Takanawa peninsula, Japan), early 1946 (Whif/modified Hasegawa kit) - WiP by Dizzyfugu, on Flickr

[Gondor]

That is looking very nice indeed Dizzy 

[Dizzyfugu]

Thank you! 

[zenrat]

I'm wondering what it would have looked like with a single vertical tail?

[Dizzyfugu]

I actually considered that, because the implanted B-47 engine fairing offers a suitable "spine" from/for the original underwing pylon as a basis suitable. But it looked (very) odd, and I had doubts about the aerodynamic consequences, so that I retained the wing fins, even though with different parts.

[zenrat]

I think it could look very "sci fi" with a single fin.  Something anime where intakes and wings are found on craft in vacuum and they fly as though they were controlled by air over flying surfaces.

[Dizzyfugu]

Markings came mostly from a PrintScale Kawanishi N1K decal set, with typical late-war IJN markings. The yellow ID bands on the wings' leading edges were created with generic decal material (TL Modellbau), Stencils were mostly taken from the Hasegawa J7W's OOB sheet. Finally, the model was sealed with a sheen acrylic varnish and a wire antenna made from heated black sprue material was added.


1:72 Kyushu J7W3 'Shinden-Kai'; aircraft "(A-343-)15", 343th Kokutai/301st Hikotai, Imperial Japanese Navy, piloted by CPO Yishida Masaoka; Matsuyama AB (Shikoku/Takanawa peninsula, Japan), early 1946 (Whif/modified Hasegawa kit) - WiP by Dizzyfugu, on Flickr

Hope I can do a photo session for scenic shots tomorrow.

[jcf]

Hasegawa based their's on the drawings/guesses that had been floating around for decades before they did the kit. Those guesses were based on written descriptions. Whinging about them being "lazy" is absurd.
🙄
Anyhow the engine proposed for the J7W2 was the Ne 130 not the Ne 20. The Ne 130 had a length of 3.85m (12' 7.5"), a diameter of .85m (33.5") and a weight of 900kg.

[Dizzyfugu]

Hasegawa just added a single different part to the kit, and it's even just a modified original piece without a hole for the propeller axis. There's furthermore no jet powerplant that would resemble/fit the original J7W's body for the huge radial engine space, and probably not a single one because the early Japanese jet engines were utterly weak. I think you'd need four Ne-20s to get some performance from a re-engined J7W. Whatever there might have "floated around", Hasegawa'a proposal is IMHO a VERY effortless kit/offer, primarily with low costs in mind.