CREATE TABLE table_name_8 (engine VARCHAR, year VARCHAR, chassis VARCHAR, entrant VARCHAR)

Name the engine with chassis of maserati 250f and entrant of luigi piotti with year less than 1957
SELECT engine FROM table_name_8 WHERE chassis = "maserati 250f" AND entrant = "luigi piotti" AND year < 1957
SELECT "engine" FROM "table_name_8" WHERE "chassis" = "maserati 250f" AND "entrant" = "luigi piotti" AND "year" < 1957