Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_68 (engine_s_ VARCHAR, tyres VARCHAR, year VARCHAR)

### Question ###
What is the Engine(s) that has  f Tyres in 1971?

### Accurate SQL ###

SELECT engine_s_ FROM table_name_68 WHERE tyres = "f" AND year = 1971