Not only is work progressing well on the TR6 project, but it looks as though work is progressing well now that everything is looking freshly painted and shiny. I have been in charge of the spray painting in two pack black and Cherine has been ably picking around all the machined surfaces and the plated bits on the engine with a brush. As usual everything is primed with Red Lead Oxide which gives for a nice long life, all the cast bits are finished in satin and all the pressed steel bits in gloss. Fitting and final assembly is to follow shortly.
Work is also well underway with the 3.8 MK2 Jaguar. The owner and I had been aware for some while that the engine was a little tired, but an extremely loud knocking had brought the car’s story to an abrupt conclusion. This is not an entirely unknown phenomenon on the 3.8 Jaguar: The engine had been originally developed by increasing the cylinder bore size of the 3.4 litre unit and by fitting liners to the cylinder block. Jaguar had initially given suitable clearance for the larger pistons by machining a chamfer on the edge of the combustion chambers in the cylinder head. It wasn’t long however before someone decided that producing two different heads for the three available capacities of engine made no sense. Therefore the chamfer was deleted from the cylinder head and machined instead on the 3.8 litre pistons. What this means of course is that it is absolutely essential to make sure that the cylinder head and the pistons in a particular engine are compatible. In the words of Michael Caine, “not a lot of people know that”. This car is a 1961 model and has a c1965 cylinder head. All was fine until the big end bearings developed a little extra clearance and allowed the pistons to start contacting the head in a somewhat noisy fashion.
Also on the subject of cylinder heads, I have been attending to one such item from a 1935 Derby Bentley which is suffering from cracks on three of the exhaust valve seats. Despite this the head is still very “saveable” and well worth doing since few good original items seem to have survived. The sensible solution will be preheated gas fusion welding which will make a nice permanent job and will also allow plenty of scope for any future repairs which might crop up.


Today saw the last of the machining operations for the Scimitar – to – Type 9 gearbox conversion with the manufacture of an aluminium bracket which reproduces the original speedo cable fitting on the later gearbox. I learned my first machining skills during school summer holidays, and it wasn’t until I reached the age of sixteen that my tuition became more formal. At that age all the engineering students – myself included – found the hand finishing of machined components to be an onerous task. Of course, like all people “of a certain age” I am now eternally grateful that in my youth I was compelled to spend hours using emery cloth to polish the file marks from steel plate, because the task is now merely a matter of course rather than a burden. In the case of this particular item I have had to rein in my enthusiasm: Having got as far as polishing with p1200 abrasive paper, the temptation was to finish off with metal polish, but instead I have to remind myself that it would stick out alongside the rough castings of the gearbox “like a nun in a snowdrift”.



