BC's current 19-game winning streak is the longest of the Jerry York era. The longest winning streak in BC hockey history is without dispute: 22, in 1949. The opening four games of the season present a real threat to this record, as BC will play three tough Hockey East road games (at Northeastern, Umass, and UML) as well as a home game against Northeastern.
The longest winning streak in NCAA history is up for some dispute. RPI claims the crown with 36 straight wins from 1984-1985, though two games were against the University of Toronto. (Thus, you could count BC's win over New Brunswick as #20, putting BC a mere ludicrous 17 game winning streak away from breaking this record.) We've yet to find an official record only counting games against NCAA opposition, though it's at least 29, with Cornell going 29-0-0 in 1970. It's not likely, but if BC starts the season completely on fire, we can start talking about these streaks.