Smallest was a 1.5l in a Honda CRX.
Biggest was a 4.1l I6 in a 1976 Nova.
Power level for the two was probably not all that different, to be honest...the biggest dog I owned was an Outback with a 2.2l engine. The first car I had that was truly fun to drive was a "RAV6", although the little CRX did handle extremely well...a friend who had a 944 in the family said the feel was comparable and he claimed their Porsche was not that much quicker.
My dad had a Merc with a 390 (6.4l), but that thing got towed away before I was able to drive. That monster took up almost every square inch of the garage in our 1950-era house and sat in there for years while dad made plans to get her running again while our functioning cars sat outside in Chicago winters.