A Special Builder's Notes


The Special Builder's Breakfast Club

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09 July 2013

Sunita (anag).

... is not far off being back on the road. I spent a couple of most enjoyable days assembling the Austin Seven Special engine under the watchful eye of Very Learned Counsel. It's been suggested that the probable cause of the break up of number 4 big-end - you might recall that the flanges of the bearing disintegrated - was the odd shape of the journal. It was 2 thou higher at the shoulders than in the middle. How this came about is a mystery but each journal was the same concave shape to within 1/2 a thou. Consequently the loads were being taken by the weakest points of the white metal and, if this is the case, it's a wonder they didn't all fail sooner!

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I've incorporated the rear oil seal mod, lightly de-glazed the bores and fitted new rings. I also discovered that the friction discs had been riveted to the clutch plate rather sloppily and one set of the rivets was worn by their bouncing off the flywheel. Other than the fun getting the crankshaft into the crankcase, all went smoothly until it came to the valve clearances. Even on the bench they're a pain. I've got a 'trials' cam so the clearance is 10 thou all round. 12 and 9 thou seemed to be a piece of cake - 10 thou was a different story. Anyway, they're now probably between 10 and 11 thou and that's how they're staying. I'm contemplating putting the gearbox on and slipping the complete unit into the car as one. For this I'll have to take the saw to a few corners of the bulkhead - it's only ply and aluminium so it's no great shakes. I'll also replace the front engine mounting studs with bolts - those and the clutch pedal, are the biggest hinderance to getting the engine in. Then there's the water pump to sort out and a bit of sealing between the radiator and the cowl. All good fun.

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I've been considering the rigidity of the body on the Hillman Special and have decided that a couple of tubular hoops fore and aft of the cockpit and some brackets, are going to help maintain integrity in the event of a roll. It's an unlikely scenario given that most of the weight is below the top of the wheels but, nudging a kerb at speed can still spoil your day. I've sent the sketch to the laser cutting people and they'll give me a call in a couple of days to ask why the measurements don't add up - rulers; I do try. Actually, the laser people are brilliant and quickly cottoned on to my occasional lapse in the measuring department and often things appear exactly as I intended despite the numbers being a bit squiffy.

A bit of excitement this morning; I was invited to go for a trip in The Great Collector's new acquisition - a 1927 Humber 14/40 tourer. Very nice it was too. A beautifully built car with real attention to detail - wind-up windows and so forth and all complimented by a 2.1lt IOE (inlet over exhaust) engine which pulled like a train with 4 up.

Of course, I should have been in the shed putting the Austin back together but heh, all work and no play....

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