It’s a strange and quirky arrangement ! In 1927, the drive ‘thingy’ for want of a better word, was advertised as being made out of “Pen Nib Steel” !! Presumably strong spring steel, but to describe it like that was very odd. I have the B & L Mk2 pump, with the ‘tell-tale’ plunger to confirm when it is working, the special crankcase door, and the long, cranked door strap that holds it all in place, and the bit of ‘pen nib steel’. I don’t want to sell it piecemeal but would consider selling the lot. No idea what it is all worth though !
Mine is a Mk2 as well. I have the complete body and innards, the deformed strap/ clamp and the frame mounted splitter for the oil pipes. I’m “just” missing the door and drive gear. I’m not sure that I would use it but it would be good to have a complete assembly.
Hmm.. I think that the factory soon realised that it was a major problem that the pump was only a single outlet, as of course the side of the engine that had the most suction got the lion’s share of the oil. They tried to overcome the problem by putting metering jets in the crankcase oil feed connections, and that may have worked well enough with a new engine, but after a few thousand miles and a bit of engine wear, the metering jets would no longer be correct. Pity really, as it is a very reliable pump, despite having a “monkey metal” (Mazak zinc alloy) body. Pumps working in the same way are used to supply oil in small but precise amounts to the bearings of jet engine turbines spinning at very high rpm.