Wednesday, October 1, 2014

There are models and then there are Models...MFH Porsche 908/03

In August 2013 I ordered a 1/24 scale kit of the Porsche 908/03, in the 1970 Targa Florio winning #12 livery driven by Brian Redman and Jo Siffert.
The kit was provided by the Japanese firm Model Factory Hiro and sold in North America by Island Collectibles, There were several reasons for laying out the money for this: 
  • I’ll want to start building it when I retire;
  • It will be unavailable by then and I will be kicking myself for not ordering it sooner;
  • It’s a proper little go-cart, enhanced by the 3-litre F1-based 4-cam flat 8, and belongs in every collection.
There are probably more kits out there than 1:1 cars, Porsche having built fewer than 20 of them. It seems Jerry Seinfeld owns the 1:1 Redman/Siffert car ... here’s hoping he's looking after it. Kit details here:

So anyway I will get around to completing the 956 pickup and sundry other styrene kits as outlined in previous posts, and I certainly intend to tackle the range of resin kits sitting on the shelf, but I would like to make some progress on the 908 over the coming winter. As a starting point, this blog entry summarizes the work to date and thus the starting point for work beginning this fall.
First impression on taking delivery of the kit in mid-September 2013 was the large number of bits, many of them spun-cast white metal, none of them with any identifying labels. Sorting out the little baggies was time consuming, getting suspension bits in one bin and chassis bits in another. There is tremendous detail here, and clearly lots of fine work will be required to make the bits all fit, unlike Tamiya or AMT styrene kits where it's almost paint-by-numbers.

Interesting that the car is about the same size as a Lotus 7 ... the 380 PS motor in the 908/03 is, however, somewhat hairier than the Cortina 1.6 litre pushrod unit, even though the latter puts out something like 90 HP with its pair of Webers.

I tackled the engine first. This began with 3 hours spent drilling out holes in the cylinder heads for oil drain pipes from the upper (inlet) cam box to the lower (exhaust) cam box and thence back to the sump. These drain pipes were to be made from 5 mm lengths of 0.5 mm wire (supplied). More drilling was required for 0.4 mm spark plug wires (they are twin plug heads, so 16 plugs) and matching holes in the distributor, all using my pin vise and number drills in the #74 to #78 range. I can see that the distributor wiring will be challenging... I am also impressed at how flexible a #78 drill (0.016” or 0.4 mm diameter) can be without breaking.
Another two hours was spent cleaning up part lines and various doweled joints around the engine. Following this I glued up the crankcase and the left and right cylinder banks. 

Separately the floor pan, gas tank pods and forward subframe came together. The photo shows a typical Porsche floor-mounted pedal assembly and two hydraulic cylinders, all bolted to an aluminum tube frame with fibreglass floor pan. Given what I have seen of early 911s, I assume these are both brake cylinders, with the clutch being cable-operated. Space frame components to be added next will include a pair of hydraulic fluid cylinders and the associated tubing. I won’t identify the spots where I have screwed up, up to you to find them.


Two steps forward, one back ... Next I assembled the fan shroud and air intake systems. The kit did not include belts for the fan or alternator, so I scratch-built these. I drilled the holes in the stacks for the injectors, and started getting myself ready, psychologically, for the challenge of wiring up the distributor. Unfortunately, while trying to clean up accumulated paint in the spark plug holes, I broke my #78 drill bit in one of said holes. The bit being hardened steel, and the head being white metal, it seemed it was pretty well stuck there. However, using a tapered diamond tip bit in the Dremel to put a slight dish in the end of the broken bit, I was able to push the bit further into the head with the tip of my awl. (Good thing I had originally drilled all the plug holes clean through the heads). So there should now be room to poke the plug wire through. 
Of course this meant identifying a supplier of #78 bits, as most suppliers provide this as part of a set of drills from #80 to #61. Micro-Mark came to the rescue here:

I can also whine about how the regular handling means paint is getting rubbed off, especially at sharp edges, but even with the screw-ups, this is one of my better efforts to date, and the mistakes are really only visible with the 4X magnifying glass. Again I will award major brownie points if you can identify the worst screw-ups.

Next I put on the oil filter, an unidentified gubbins driven off the rear of the left side inlet camshaft, the fuel injection pump, an oil feed tube from said oil filter to said injection pump, and the 8 velocity stacks. I assembling and painted the spaghetti-maze of the exhaust system (it's set up as a pair of flat-4's end-to-end, is this the last vestige of the VW heritage?), and drilled and tapped the M1.4x0.30 hole in the front cover that will take one of the screws holding the motor to the chassis.

And this is where things ground to a halt, in early January 2014. I spent some time in February and March 2014 moving furniture and hammering on nails, and discovered that while these activities improved my core strength, they destroyed the fine motor skills necessary for this level of modeling. Then spring came along and I got the bike out ... see my separate blog on this topic.
Meanwhile I ordered a kit of the fearsome 1970 Porsche 917K from the same supplier, also because I didn't want it to be sold out when I finally get around to building it. If the 908/03, with its 3-litre flat 8, was the weapon of choice on twisty tracks such as the Targa Florio or Nurburgring, the 917, with its monster 4.5 litre flat 12, was well suited to high-speed tracks like Daytona or Le Mans. The next generation of Le Mans cars, culminating in the unbeatable 956 and 962, involved plenty of aero bits; the 908 and 917 were the last of the old-school racers built with little or no understanding of the importance of an aero undertray, and the drivers of these cars were certainly heroes in taking these little hot rods out on to the Mulsanne at 250+ k/h with all that front end lift. Ooof -- I know I'd be lifting off across that little hump on the Mulsanne.
The version I ordered replicates the 917K as driven by Redman and Siffert,  and which also now belongs to Seinfeld ... clearly he has good taste in classic cars. Redman and Siffert didn’t win Le Mans in 1970 (a 917 operated by the Salzburg AG team won), but the car carries the same classic Gulf Oil colours as their Targa Florio-winning 908/03, so there is a link between the two cars.
Stay tuned as the cooler weather starts and the opportunities to get out and ride the bike become fewer.
Originally posted 1 October 2014

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