Lister took a cam drive that was just good enough for a single and doubled the load on it, trouble should be expected!
Exactly! Doubling the load on the camshaft gear taper pin, was a sure fire winning approach to creating problems later on down the line, even the Indians recognised this as a problem area in the original design, and beefed up the hub of camshaft timing gear casting. So as to try and overcome this problem, but this was more of a sticking plaster type solution which never totally cured the problem of the taper pin working loose. It just transferred the problem of the taper pin working loose from the timing gear cast boss, to the 7/8" diameter camshaft spindle.
Listers never really learn't their lesson in this regard, because when they created the Alpha range, the camshaft timing gear relies solely on an interference fit with the camshaft. Which is also a known weakness on this engine range particularly on the 3 and 4 cylinder engines for the same reasons as identified above.
They also took a marginally strong crankshaft and made it twice as long at double the loading,, trouble should be expected.
They also failed to double the bearing area, hence why a lot of the twins suffer from failure of the centre main bearing (as it gets the most loading, and has the smallest surface area of the three main bearings).
The lack of internal balance weights on the crankshaft is also another serious design flaw with these engines, which is further compounded by having the opposing out of balance force (flywheels) so far away from the source of the out of balance forces. Have you ever seen any twin cylinder Listeriod clones with crankshaft balance weights?
Compare and contrast the differences in the crankshaft from a CS 16/2 (three main bearings) to a Lister CE (also 16 BHP) which has 5 main bearings of considerably bigger diameter than the CS. This is the difference between an engine which was modified from an existing design AKA the Lister L type and one which was created from a blank sheet of paper.
A sensible option which would of been easy to implement, would have been to drastically increase the centre main bearing diameter (which I suspect is what the Indians have done to the large displacement CS twin clone engines, in an attempt to improve reliability).
A few years ago one of the parts stores in England had quite a few twin crankshafts made up to OEM specs. They were quite spendy but didnt last long.
I know who you mean (IIRC weren't they been advertised as an OEM part) I almost bought one myself at the time, but managed to find a NOS genuine article in the end for a lot less money.