Valve Gear Oil Feed Pipe

[Mike Allfrey]

NUMBER ‘1’ CYLINDER HEAD STUD REPAIRS
Having been involved with Javelin and Jupiter engines for over sixty years, it has come as a surprise to find a crankcase with one of the valve gear oil feed pipes completely missing. Somewhat stupidly, I have become involved with yet another crankcase that has been visited by Artful Bodger – several times. The missing oil feed pipe appears to have been caused by the repair at the number ‘1’ head stud’s stripped thread in the crankcase. It seems that the repair was so successful that Artful felt that the stud could then be super-tightened in its thread. This may have been to the extent that the flared copper pipe’s supporting boss broke away into the tappet chest.
Maybe the perpetrator of this disaster decided to simply remove the pipe assembly and leave it at that. Then along comes a new owner of the crankcase assembly who has bought boxes and boxes of bits and not really knowing what belongs where. It is all scattered over my workshop bench and, truly is something I did not need.
My main question is this, has anyone out there been involved with such a repair?
My initial thoughts about this repair are this, machine a special drilled stud, with a long threaded protrusion into the tappet chest. The stud would be tightened home against its shank. Where the threaded end protrudes, thread on a machined fitting that has a female 3/8” BSF thread and an olive setting union to suit the new pipe. This may well be too simplistic a way to make a good repair, and such a stud will require a long drilling for the oil to pass through.
Any comment on that? All ideas are welcome.
The first act of Bodgerism that caught my eye was a 3/8” stud sticking out of one of the rear timing cover hold down threads. The thread used is a mystery, it certainly wasn’t BSF, BSW, UNF, UNC, metric standard nor metric fine. Could it be Lanchester? Artful had also been at the two rear support bosses for the Jupiter fan support, and the same unknown 3/8” thread had been employed. These enlarged threads can easily be repaired by using 12 mm Keenserts with 8 mm bolt thread.
The rear timing cover holes looked out of shape and require sleeving to bring back to standard.
The front timing cover has a 1/32” step down to the sump gasket face on the crankcase; a bit much I would think for reasonable concentricity at the front crankshaft seal. As for the flywheel housing, that cannot be checked yet due to the absence of dowels.
This has also been placed in the Jupiter section.
Regards all,
Mike Allfrey.