5 0 ▁( 1 9 3 0 – 1 9 3 5 ) ▁ ▁Origin ally ▁the ▁Series ▁ 5 0 ▁had ▁a ▁ ▁six ▁cyl inder ▁engine ▁developing ▁ 9 9   b hp ▁of ▁power ▁at ▁ 2 , 8 0 0 ▁r pm , ▁and ▁Bu ick ▁manufact ured ▁ 2 8 , 2 0 4 ▁cars . ▁In ▁ 1 9 3 1 ▁the ▁model ▁remained ▁almost ▁un changed , ▁aside ▁from ▁minor ▁appearance ▁changes . ▁Option ally , ▁the ▁model ▁was ▁equ ipped ▁with ▁a ▁new ▁ ▁straight ▁eight - cy l inder ▁and ▁ 7 7   hp . ▁With ▁the ▁temporary ▁disapp earance ▁of ▁the ▁Series ▁ 4 0 , ▁Series ▁ 5 0 ▁became ▁the ▁entry ▁level ▁model ▁for ▁Bu ick . ▁ ▁In ▁ 1 9 3 2 ▁the ▁engine ▁disp lacement ▁increased ▁to ▁, ▁producing ▁ 8 2 . 5   b hp . ▁In ▁ 1 9 3 3 , ▁the ▁a est het ics ▁of ▁the ▁car ▁was ▁completely ▁red es igned . ▁The ▁power ▁delivered ▁by ▁the ▁engine ▁was ▁increased ▁again ▁and ▁now ▁it ▁was ▁up ▁to ▁ 8 6   b hp , ▁and ▁in ▁ 1 9 3 4 , ▁the ▁model ▁power ▁increased ▁to ▁ 8 8   hp . ▁Bu ick ▁re - int rodu ced ▁the ▁Series ▁ 4 0 , ▁which ▁once ▁again ▁became ▁the ▁entry ▁level ▁model . ▁In ▁ 1 9 3 5 ▁the ▁Series ▁ 5 0 ▁remained ▁un changed ▁and