Supermarine Spitfire Mk30

Supermarine Spitfire Mk30, Allison V1710 engined, high altitude, long wingspan, what-if.

Originally started this project in 2017 using the HobbyCraft Seafire Mk XV. Part of me wants to continue down this route, but the other part isn't satisfied with the execution. Further, now I'm contemplating kitbashing an Allison V1710. To do that requires a fresh start. Additionally, I have new ideas...wing root radiators for instance.

Full notes:

Still not 100% on the name. Mk30 because I think there was a gap in Spitfire naming that this would slot into?

Allison V1710 engined, high altitude, "what-if". UK equivalent to the Fw-190D or Ta-152.

Current thinking:

Airfix Spitfire MkXII as base. Why? Well, I have one in the stash, for starters....While Griffon-engined, the cam bulges on this kit aren't molded into the cowl. And the Allison will fit into the same volume as the RR Merlin, so no need for bulges. This might be immaterial if I use ICM bits (cowl, etc,: I'm still hoping to kit-bash an Allison into this, and will use the engine bay guts from the ICM kit). In looking over the ICM kit, I don't feel its robust enough to use by itself for my intentions and I think that issue will work against me significantly if I were to go down the ICM route. Further to all of this, while I love the bubble top Spits, I think the aesthetic of the "razor back" is what is more appropriate in this case. I would have opted for using the PR XIX kit as that checks all the boxes but for cam bulges molded in, and it's currently rarer than hens teeth.


Allison V1710 dimensions:
W: 29.3" (744 mm)
L: 86" (2184 mm)
H: 37.6" (955 mm)

Rolls-Royce Merlin dimensions:
W: 30.8" (780 mm)
L: 88.7" (2250 mm)
H: 40" (1020 mm)

Rolls-Royce Griffon dimensions:
W: 30.3" (770 mm)
L: 81" (2057 mm)
H: 46" (1168 mm)


Mods to include:
New external exhaust stack for turbo. The part I did for the prototype was literally the first part I ever drew and had printed. So I'll have a major rethink of what it should look like without the early-days CAD skills the first part endured.

Moving engine bay forward to provide space for exhaust to converge. Small move, 5-10mm MS max i should think. This will allow a separation between the hot exhaust and the forward fuel tank as it routes into the plane, converges right and left bank, and then plunges down to the turbo beneath. Will add small auxiliary coolant ducts to feed this area. On the original prototype I did give this point much thought.

Turbo location in bottom of plane, sticking out in air stream ala P-38, slightly ahead of pilot as on prototype.

Turbo inlet? I used P-38 inlet on prototype as a nod to the engine's roots, though it might be fun to draw and print something bespoke, Anglicized of course. Maybe not though and stick with P-38 inlet? It's a cool nod after all.

New wing root radiators to be drawn (Tempest MkI and Mosquito inspired).

Wing extension. In a perfect world I'd start the extension at the wing root in order to push the landing gears outboard as that makes sense architecturally. Unfortunately that location comes with ready made issues on the kit (convergence of a bunch of surfaces, location where wing attaches to fuselage, etc). On the prototype I did the extension outboard of the guns location, or close to that. I might have to again do it there.

Will use ICM triangular wing tip extensions.

Tail extension. Might re-utilize the Mk22/24 tail that is on the prototype, cut it off, and graft onto this kit. Small move rearward, 5 mm MS.

Contra-rotating props. Done, and still satisfied with them, so will reuse (especially after correcting blade rotation issue!).