My biggest engine in a vehicle was a Sierra Denali with the 6.0 (2003, AWD with 4 wheel steering, that was one of the best vehicles I ever had).
My last boat had an 8.1 in it, does that count.
By contrast, my 1987 RX-7 Turbo had a 1.3L. I think that's the smallest car engine. Heck, I've had motorcycles with bigger...