nope.  4 cylinder.

i wasn't aware that there was another Infiniti with a V-8 besides the Q45.

several.  the 740i, 730i, 540i, 530i.  (4.0 liter and 3.0 liter V-8)

one or two?  there's at least one V-8 for every platform except
the compact (190E).  S-class (400SEL, 500SEL), W124 (400E, 500E),
and roadster (500SL).

acura doesn't have any V-8 cars at the moment.