Blaze1 wrote: ..... as I've never seen a configuration with more than 2 rods per arm. As for the articulated rods, I've always liked the idea of the blade and fork style. I think the forks would have to absorb friction from 4 surfaces as opposed to 2 for the blades, perhaps this and structural issues is why the configuration isn't used for high revving application.
the Life F1 car in 1990 raced with a 3 bank 12 cyl 'W' aka 'broad arrow' designed by Franco Rocchi (ex-Ferrari & MV flat 4 prototype)
I believe it had 3 normal rods side-by-side on each crankpin
others have done similar paper designs eg Munday ? did a DFV-era W12 and Ferrari considered W18s (more than once imo)
some might not classify fork&blade as articulated
true articulated ie master & slave or link rod design gives less piston sideforce but unequal geometry
eg a typical radial (9 cyl) has reduced sideforce on 8 pistons
the Napier Lion W12 had master & slave rods, similarly old aero V12s had link rods
the Napier Cub was an unusual 16 cyl design
the c 55 litre W18 Isotta-Fraschini was available post WW2 in diesel form only ? (and race-winning gasoline V12)
a developed diesel V12 is still available, though the maker's name has changed
currently new 30 litre 9 cyl traditional design radial aero engines are available (from Poland ?), now aimed at natural gas-driven generation
and the 7 bank 56 cylinder turbocompounded marine diesel (Ukraine or Russia ?), in the usual paired setup giving 10400 hp