Brandis If it does need a squirt to lubricate the bore, by my reckoning it would be better directed to the thrust side of the bore, not to the side.
The old cast iron block Ford Crossflow engines had this feature, the drilling emerging just above the big end bolt thread. I do not know if more modern engines use this scheme, but my old Escorts and Capri's were good for leadfoot heroics back in the days of cheap gas and a youthful more liberal approach to motoring law. The engines were regarded as well tough.
BSA must have had their reason for adding the hole to the side of the rod rather than facing the rear of the engine. There will be a theoretical two squirts per revolution whichever way it points....the pressure source is the same, that hole on the shell.
To add to the conundrum, a Longstroke crank to hand has two oil holes drilled on the timing side big end journal. but only one on the drive side. This faces upwards on the compression stroke, bob weights horizontal. All the journals are notched to carry the oil (later cranks have an eliptical cup) even where the hole should be!
This 3 hole situation has been found by other Forum members, and whether it was a production line error or a design feature was never resolved. This crank has a large cutaway to the Flywheel between the big end journals, which I have always taken to be characteristic of the Longstroke crank, and present on all cranks I have actually examined, all from ZA7 Series engines. Web images also show cranks with just balance holes drilled here as normal, but in these cases the descriptions are those of the sellers, but it would be interesting to see if alternative crank and flywheel features exist within earlier and later Longstroke parts portfolio using the conventional split shell crank design. Your crank does not have this cutaway as far as I can see.
Pictures of this cutaway flywheel crank from a ZA7 can be found on a previous post of mine...Search Longstroke Crankshaft in the A7 46-50 Section.
Swarfy.
