One the subjects that we on the group never got round to discussing was the matter of compatibility, between parts in particular but also in general for things like engine accessories, air cleaners for example.
Back in the 1920's and 30's there were not many suppliers of things like air cleaners, so makers like Lister didn't fit them, full stop. Later on, there became available a few makes of air filters and oil-bath cleaners which turn up across a range of engines but never seem to have the connection made.
Injection equipment is another area where a lot of parts are exchangeable, with the obvious exception of things like pump elements and nozzles and maybe delivery valves. Of what is left, nearly all are common parts across a range of engines. The BPF1B pump for example, has almost 100% commonality of its major parts across a range of UK and overseas engines, only the element, rack and housing change much.
Magnetos are another area in which a lot of the major parts from a series are common, with just a minor set of things like mountings and drives being different. This may not be as fruitful a source of bits as some may like, but the BTH mags had a basic range which was modified to suit a specific application, same with the Wico A series which was probably the most-fitted magneto in history.
Carburettors have their foibles but the Solex and Zenith ranges have many coomon parts as with the items listed above, albeit needing a bit of research.
Spark plugs we know about generally, and personal preferences/experience seem to guide what is used as much as the original makers recommendations!
Maybe I'll get a listing together of such bits and pieces one of the days and see how much stuff we can find.
Peter
-- Peter & Rita Forbes snipped-for-privacy@easynet.co.uk Engine pages for preservation info: