DIY 1/32 Spey Phantom conversion

[ThomasProbert]

 Morning all,

Like 99% of those who enjoy building large scale Phantoms, I've been eagerly awaiting a 1/32nd scale RR Spey powered version for as long as I can remember. There is of course the Wild Hare conversion that usually sells for more than my car is worth (on the rare occasion one actually comes up for sale) and rumours are abound that HK were looking at doing one, but I thought life's too short to wait around any longer and it's time to start hacking about at the classic Tamiya F-4J kit. 

Before I go any further, it's important to say that this is not going to be wholly accurate and the majority of this is being done with the MkI eyeball and approximate measurements. I'm simply not interested in this (or any of my models for that matter!) being accurate to the nearest half-mill, and therefore what you'll see is something that (hopefully) will look like a British Phantom but won't necessarily be the definitive way to go about such a conversion. Lots of inspiration has come from @Wingco57's excellent conversions and you'll undoubtedly notice some similarities between the two!

I wasn't going to run a WIP for this as I was concerned about burn-out and failure, but I've actually come a lot further in a short space of time that I had initially anticipated, and I think  broken the back of this conversion, so thought I'd share my efforts just in case there's someone else out there considering the same thing...

I thought I'd begin somewhere nice and simple, so tackled the belly of the beast and the inlet doors on the underside. The UK Phantoms have these further forward than the US examples, so it was a case of cutting out the new doors in their forward position, and filling the old ones with plastic card blanks:

 

These were then filled, re-scribed and given a quick squirt of primer:

Step one complete!

The next step was the far trickier intakes. The Speys demanded more air and thus the intakes were significantly wider than the US versions. There is much debate and head-scratching about how exactly the shapes differ, but I've done a bit of digging around and modified mine as I see fit. 

In 1/32nd scale, my calculations work out that the intakes are roughly 3mm wider at the front than the US examples. Therefore, I sourced some 3mm strip and carefully cut the kit intake sections in half, front to back, adjacent to the grills on the inner edges of the intakes (the pictures will explain this better). 

 

Here you can see how much wider the UK version intakes are than the US version - quite a significant gap emerges when test fitted to the unmodified rear sections:

 

To remedy this, the fuselage will of course need widening too, and the shaded area in the picture below shows the section in need of modification:

To do this, horizonal cuts are made along the top of the intake trunking, with vertical cuts made to allow the section to be opened up. There is a lower horizontal cut, too, made at the wing root to allow to original kit fixings to mate together for strength whilst allowing the wider intake to slot over the upper wing surface:

A wedge of plastic card in then inserted, with the forward-most part being 3mm in width to match the modified intakes:

Lots of reinforcement was given to the interior too:

I'm going to use FOD guards on mine as life is too short to tackle the notorious intake interiors on this kit, but if you were to have them open a further 'wedge' would be needed to plug the gap seen above. Before I went any further, I wanted to check the modified fuselage would allow the wings to fit - which by luck more than careful calculation they did!

The modified intakes were then test-fitted to the modified fuselage:

Before they were glued firmly into place and allowed to set for 24 hours:

The join wasn't perfect but considering the amount of butchery that went on I was pleasantly surprised.

Some Milliput White soon made light work of the affected areas:

And after some re-scribing and a shot of primer, things look good!

 

You can see in the picture above I have started work on the back end and opened up the extra doors the Spey versions have on the rear fuselage. I'm going a later version with the pod on the top of the fin, so plans were consulted and a rough shape made for these from plastic card laminates:

This still needs an awful lot of refining and surface detail added, but it's a good start. 

I'm now going to have to concentrate on getting the cockpit done and then I can begin hacking about at the rear end. The Spey exhausts are a fair bit bigger than the US ones, so the hacksaw and filler are at the ready!

When done, I'll update this again...

All the best,

Tom

[BlrwestSiR]

Wow Tom, you actually make it look easy. Which it isn't but still. 

What are you going to use for the burner cans?

Carl

[ThomasProbert]

19 hours ago, BlrwestSiR said:

Wow Tom, you actually make it look easy. Which it isn't but still. 

What are you going to use for the burner cans?

Carl

Thank you! I have some 3D printed cans ready to go, and have a cunning plan for the jet pipes. All will be revealed in good time…

Tom

[Dave.]

Hi Tom I've just started a tamiya F4J conversion to an RAF Spey powered phantom. So seeing this post is going to be very helpful for me. I see you haven't posted for quite a while. Any more news?