Table schema:
CREATE TABLE table_name_17 (d__max_ INTEGER, taper VARCHAR, c__max_ VARCHAR)

Question: What total D (max) has a taper of 1:20.047, and a C (max) bigger than 65.5?
SQL: SELECT SUM(d__max_) FROM table_name_17 WHERE taper = "1:20.047" AND c__max_ > 65.5