1/8 Porsche 935/78 'Moby Dick'

[nugundam93]

Always awesome with the little details!

[ScratchBuilt]

Hello again,

Engine updates tonight. Remember all the turbo parts hanging from the main rear engine mounting plate? Well, I reached the point where that lot had to be fixed in position in order to continue making progress. So, time to take a deep breath and start gluing and pinning the four styrene brackets into place:



Each bracket has three pins - these will be filed smooth in time and have nut detailing added. Note also how the two compressor units at each end have been pinned - this has allowed me to start working on the connecting pipework to the intercoolers (black 6mm fire-extinguisher flexible ali hose).

With the core turbo parts fixed, I could add the two waste-gate units below. My first thought was that I would have to cut the kinked mounting plate from ali or brass, but an offcut of fibreglass from one of the dashboard panels provided a much easier solution:



Here the mounting plate has been drilled and pinned in place, and I've started on the pipework which connects it to the main exhaust branch. Since this photo was taken both these pipes have been drilled, pinned and greenstuffed. I've also added the two flanges between the turbo units and the exhaust primaries - these need more detailing, but have allowed me to finalise the exhaust positioning. The primary on the left-hand side needed a little cutting-and-shutting to get the alignment correct, too.



Here's the engine back in the car, with the main mounting plate pinned through to the chassis. The two central exhaust tailpipes are not finalised yet - they might need angling downwards to suit the bumper section in the rear bodywork.



Finally, here's the right-hand connecting pipe to the intercooler. The white sections of styrene tube for the hose pieces have been cut at an angle and re-glued in order to get a little curvature into the pipes. The hoseclips are a combination of 1.5mm x 0.25mm strip, 1.5mm rod, and more of the 'Wave Option' styrene hex-nuts.



I've still got plenty more to do in this area, but at least I can start finalising things. The intercooler connecting pipes, for example, are both finished and can be painted and put aside until final assembly - I don't have to trim them again in six-months time. I've now got to work out all the little oil feed and lubrication lines running from the main engine to the turbo units - so that'll be an evening studying the photos and books.

That's all for tonight. Have a good week.

SB

[prog4ever]

This wonderful project doesn't stop to amaze me!

Got no words to define it.

Congrats and keep-on-going!

Art

[chris24]

I still don't understand how all your achievements so far are humanly possible : every little parts fit exactly into place, all the measurements are perfectly respected...

You must have worked at the development of the real Moby Dick in a former life !

[ScratchBuilt]

Hello again,

Should have posted this last night, but the connection was being hit-and-miss, so decided to wait.

More engine-related work to show you. You might remember how I made the basics of the throttle linkage several months ago (actually, probably many months ago!). Now that the inlet manifolds and intercoolers are in position, I could start finalising the details. Here's the linkage in kit form:



Here you've got the various lever arms which will connect to the throttle butterflies, fuel injection pump, etc, plus the main pick-up for the throttle cable in the middle. The two springs provide a return mechanism and act on the two mounting blocks and the extra pair of levers. There's a couple of little clamping-block details on each end, and a few of the really small Wave hex-nuts.

Next, you've got these two small control valves which are a common feature on the Porsche turbo engines of this period. I confess I'm not entirely sure what they're for - they're on the inlet manifold side of the intercoolers (rather than the turbo side) and by the looks of the linkage they're possibly intended to operate only at a certain point. Given that they are not duct-fed from the outside and just exit into the engine bay, I don't know whether they're just a relief valve of some sort?

All of which is not really important, of course! The curved pipes were made by threading sections of tube over a length of small-bore aquarium hose, with greenstuff to fill the gaps. There'll be a couple of small levers added to each valve, with the shaft running through the ali tube in the middle. Again, more Wave nuts to finish things off....mmm, so much easier than making them myself! The mesh grilles were stamped out using a regular home-office hole-punch and CA'd into place.





Finally, here's the linkage in place on the engine:



The short diagonal tube in the right-hand corner of the engine bay has been moved over slightly to give more clearance - not much, but you can see the difference by comparing the position to the ali tubes at the extreme bottom of the photos. Whilst greenstuffing the curved pipes I added some more weld detailing around the engine bay.

So far, so good. Everything clears where it's supposed to, and I should be able to connect all the various levers and pushrods as required. That'll be the project for this week - very fiddly stuff, though!

That's all for now,

SB

[codea]

I have watched fellow modellers struggle to find superlatives to describe your work, so I am not even going to try. Once in a half lifetime some one comes along who puts this kind of effort into model building and takes it from a hobby into art. The fact that you can create such detail and that you do it without a dedicated table, specialist tools or equipment is just amazing. I know from your posts that you are a motor racing enthusiast so I know a lot of what you can add to the model comes from understanding what a racing motor requires plus all your research. I have learned so much from you. Quite simply thank you for sharing your talent with the rest of the world, you are truly amazing.

I can see that throttle linkages etc are important to the model, but how do you decide where to draw the line on detailing?

[ScratchBuilt]

Hi codea,

Thank you for your kind comments - much appreciated. I know that there are certain aspects of my approach to modelling which are different to 'the norm', but I feel that ultimately you have to enjoy the process, you need to have an interest / enthusiasm for the subject. For me, for the last twelve years or so, it's been 70's Porsche - and a steadily growing collection of books, photos and die-cast models! When a project can take years rather than weeks or months, you've got to maintain the belief that the end result will be worth all the effort.

Where to draw the line on detailing? Hard to say - it varies. Sometimes it's the lack of reference material that limits what I can do, or lack of suitable material to work with. At 1/8 scale even in styrene things start to get heavy, so strength and structure is probably more of a concern for me than for most people. I'll sacrifice a little detail if it means something won't fall apart! My worry with the 935/78 is the way the engine and gearbox is mounted - I'd like to add some extra supports, but without making it too obvious. I admit now that I'm not looking forward to tackling the headlights, or the Martini stripes...

A big part of my effort to add detail is to keep things interesting for everyone following the thread - especially when some of the same parts repeat themselves on different projects. I'm looking at how I can add another layer of detail, how can I improve on what I did last time - can I make the same part in a different / easier / faster way? I'd like to think that if I posted something that you guys felt was not 'up to standard' you'd soon let me know!

SB

[ScratchBuilt]

A quick update tonight.

My main focus this week has been the assorted rods and joints which connect the main throttle lever cross-shaft to the various parts of the engine. Apologies for the lack of 'in progress' photos with this one - given the fiddly nature of the parts, I was concentrating more on making them, than shooting them!

Anyway, here's the cross-shaft from last time with the extra linkages added:



...and a close-up of one end:



The main rods are 0.78mm brass. The rod-end detailing is a mix of 2mm round styrene, a thin slice of hex, and the black sections are outer sheathing from a length of wire. Everything's pinned together with 0.65mm wire, and will eventually be fully hex-nut detailed.

Here's the linkage on the engine:





The last rod will drop down to connect to the side of the fuel injection pump - slightly tricky as there's not too much space between the inlet manifold and the pump. The two levers at the top of the manifolds need spacers fitted to get the positioning correct, but that's easy enough to do. All the rods are cut to length and the end fittings CA'd in place - it's now a question of how much of it I can fully pre-assemble before painting without causing any problems.

That's all for tonight,

SB

[88Porsche944]

SB,
Your updates never cease amaze. Outstanding work!


Trevor

[ianc911]

Gorgeous as usual. That would have taken me weeks to build!

ianc

[ianc911]

Gorgeous as usual. That would have taken me weeks to build!

ianc

[ScratchBuilt]

Hello again,

Not a huge amount to show you tonight - there's a couple of things I've done but not photographed, and more stuff that's very much 'in progress' until the weekend. However, the main thing I wanted to discuss was how to get a suitable surface finish on the intercooler housings...

So, the intercoolers are encased in the two housings which sit on top of the inlet manifolds. From period photos these housings are (I'm assuming) of aluminium construction, but at some point are painted or dipped in a textured coating. I guess it's a thermal barrier of some kind, but it's basically like a crackle-finish on a manifold. I don't want to simply paint the intercoolers plain black - I want to try to replicate the fine textured surface of the real car.

My first thought was a combination of glue and micro-balloons, but a quick test suggested this was not going to work. Maybe my balloons are too small? Do they do different sizes? Will check. I tried spraying a test-piece with hairspray (thanks, mum) to see if this would dry with an appropriate surface, but no luck. However, a can of spray photo-mount produced an interesting result:



For scale, the styrene strip is about 1" tall. I sprayed the photo-mount, then used a toothbrush (not mine..!) to get a more suitable stippled finish. After it had dried I gave it a quick coat of grey primer, then a coat of my regular Citadel 'Chaos Black' and a little drybrushing.

Although (as you'll see below) it's an interesting and potentially useful texture, I don't think it's quite right for the intercoolers. A conversation with colleagues at work led to the idea of using glass blasting beads (approx. 0.4 - 0.5mm diameter), in the same way you would apply scenic grass 'flocking'. So, more tests - this time I made sample pieces using both photo-mount and a coat of PVA glue for the adhesive layer. Here's the results:



On the left from top to bottom you have:
Glass beads on photo-mount.
Glass beads on PVA.
Photo mount mk1

...and on the right, photo-mount mk2.

The photo-mount texture looks like it would be really good for creating the scrubbed surface of a slick racing tyre - providing it doesn't eat into the foam first! I can do more tests later to see if this is an option. I will try a new fresh can of photo-mount before making a final decision on the glass beads - the can I've been using is spraying a bit thick and lumpy, so maybe a fresh can will give a thinner, finer coat? Using PVA brings the advantage of being able to get the glue exactly where I want it, but it might not be as durable. Another option would be to get some used (smaller) glass beads to try.

So, any suggestions? Might have to check out some of the big 1/12-scale 935 build threads around here for more ideas...!

Finally for tonight, I spent some more time on the water header tank. A thin trace of blue paint around each of the three windows to be the sealant, then each 'screw' was CA'd in place, snipped off, then filed flat. There's way too much dust showing in the photo, I know, but the finished piece will look okay when it's in position on the car.



...and yes, the screws on the real thing are also not perfectly aligned or evenly spaced!

See you next time,

SB

[The 5th Horseman]

Scratchbuild in the purest sense of the word!! I have been modelling for some time now and i can clearly recall the times when the words ''aftermarket'' and ''photo-etched'' were basically unknown to us modellers. Although today you can add fantastic detail with the myriads of items now available to us, this work that you do is truly inspiring!! After looking at your models i have to consider myself merely an assembler, not a modeller now!
Carry on...

[is200_adelaide]

This one is a bit left field but have you tried castor sugar? I've found it gives quite a good texture, even in 1/24 scale. My method usually involves spraying clear coat first then applying the sugar while it's still wet then color coat over the top.

[The 5th Horseman]

Hi SB
if you are looking for a grainy surface i can suggest using sanding paper.. you can use fine or coarse depending on the effect your after, and you can cut it and shape it and bend it and glue it easily...