with some pictures of how I did mine.
There are only two things you need to do to the engines inner cover to do this.
1) You need to block the oil feed from the o-ring grooved feed hole to
the crank oil seal, point A -> point D in photos 1 & 2. In order to do
this you need to remove the blanking grub screw from the cross drilling and
re-tap the thread (2BA if my memory is correct) deeper so it bridges the gap from A -> D.
You can then blank off this feed with a grub screw. I then opened up the original 2BA
thread to 1/4 UNC and tapped it just enough to blank the end off just as the original screw did.
What you end up with is an extra grub screw between points A & D to blank the feed off.
2) You now need to add a new oilway at point B so the oil from the feed pump can leave the
engine (not that they ever need much encouragement to do that!!!). To do this the inner
cover has to be accurately mounted for the drilling of the new oilway at point B. This can
then be drilled through to point A and also be tapped out to 1/8" BSP just the same as the
original pressure switch drilling at point C. I think you can only do this on 68 and later
engines as the metal was added here for the 68 Triumph 250 for their oil pressure switch was
fitted there rather than where it is on the BSA's but I may be wrong on that.
Regards JB
Some other photos.
