CREATE TABLE table_69943 ("Year" FLOAT, "Entrant" TEXT, "Chassis" TEXT, "Engine" TEXT, "Points" FLOAT)

What engine did Scuderia Ambrosiana with fewer than 4 points have?
SELECT "Engine" FROM table_69943 WHERE "Entrant" = 'scuderia ambrosiana' AND "Points" < '4'
SELECT "Engine" FROM "table_69943" WHERE "Entrant" = 'scuderia ambrosiana' AND "Points" < '4'