Friday, January 3, 2020

Ford P68: Overview and DFV

A sad little footnote, was the P68, aka F3L. Unstable at high speed due to insufficient downforce, and bedevilled by a litany of mechanical failures, it never finished a race. One driver crashed badly enough to end his career, at the Flugplatz at Nurburgring. But it was a gorgeous little car, with very low drag coefficient and frontal area; combined with a Cosworth DFV engine, very high speeds were possible. The slippery shape and story of failure due to negative downforce (i.e. lift) are reminiscent of the Matra 640 which I built some time ago.



The kit is typical of MFH, with oodles of detail, and reproduces the car's initial outing at Brands Hatch in early 1968 as driven by Bruce McLaren and Mike Spence until a driveshaft failure put them out. (The car never finished a race, mostly due to silly mechanical failures). But the monocoque floorpan also means there won't be a lot of fiddly little chassis tubes as in the 908 or 917. And I am not yet ready to tackle the two gems in the stash, the Alfa 33 Stradale or the Aston DB4 GT Zagato, so this is the first new WIP for 2020.

Here the white metal bits are heading for the acetone bath, then to the bench for drilling out of sockets for all the doweled joints.



Initial gluing of engine components is done, followed by Tamiya metal etch primer, Tamiya white primer and the appropriate Tamiya colour. Many MFH builders put their white metal bits through a jewelry tumbler for polishing but I prefer the rough surface for aluminum castings, and will count on primer and paint to fill in fine roughness. I will file or sand out coarser roughness as needed.



The DFV is well modeled, with 0.014" wire for the spark plugs (about 0.350" at 1:1). But the clear tubing for the injectors, at 0.039", is way too stiff as well as being huge (about 0.950" at 1:1). The engine block and gearbox casing got some weathering via Tamiya Panel accents, brown for that slightly greasy look on the gearbox, grey to tone down the gloss aluminum on the block.



So I'll be looking for alternative tubing as the piping is right out in full view. Of course the injection pump is the Lucas unit with pipes coming out at all angles; as it is buried inside the V below the throttle slides, pipes will just get shoved down into the narrow space available without worrying about whether they actually connect with the pump. The Bosch item used by Porsche was much easier to plumb up at this scale. So I used yellow spark plug wiring, and pushed it into short little bits of the clear plastic tube which in turn was slid over the injectors.




Finally the kit comes with 8 lovely little brass mesh caps to go over the stacks, but I'll leave that aside for now while I figure out how to get them to sit square and take the glue without sticking to everything (such as my fingers). Maybe it needs white glue, or perhaps 5-minute epoxy, instead of the CA stuff. To be decided.




Stay tuned!

4 comments:

  1. Hello, I have this very kit and would like to start on it. In terms of parts cleanup, could I use a 99% isopropyl alcohol? Or is acetone found in paint sections of hardware stores ideal?

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    1. Use isopropyl alcohol, 91% or 99% depending on what you can find locally, on the resin. Use acetone only on metal! It will dissolve the resin. Perhaps the major item to watch for is the rear tires are much too large and don't allow the rear engine cover to close completely. Otherwise an excellent kit. Enjoy!

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  2. Thank you for such a speedy reply. How many pieces would you estimate this kit to have?

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