Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_64 (constructor VARCHAR, grid VARCHAR, time_retired VARCHAR)
### Question:
What constructor has a grid less than 21, and time/retired of engine?
### Answer:
SELECT constructor FROM table_name_64 WHERE grid < 21 AND time_retired = "engine"