▁respectively , ▁then ▁ 7 1 ▁for ▁the ▁Series ▁design ation , ▁referring ▁ ▁the ▁nom inal ▁disp lacement ▁per ▁cyl inder ▁in ▁cub ic ▁inches ▁( r ounding ▁up ▁). ▁▁ ▁Like ▁most ▁Detroit ▁Dies el ▁two - cycle ▁engines , ▁the ▁ 7 1 ▁Series ▁are ▁equ ipped ▁with ▁a ▁blow er ▁yet ▁still ▁referred ▁to ▁as ▁" n atur ally ▁asp ir ated " ▁( SA E ▁design ation ). ▁These ▁do ▁not ▁have ▁a ▁model ▁suffix ▁identifier : ▁ 6 - 7 1 ▁is ▁an ▁inline ▁ 6 . ▁When ▁the ▁model ▁number ▁includes ▁a ▁suffix , ▁it ▁denotes ▁additional ▁features . ▁Eng ines ▁equ ipped ▁with ▁need le ▁unit ▁fuel ▁inject ors ▁and ▁commonly ▁four ▁exhaust ▁val ves ▁per ▁cyl inder ▁are ▁indicated ▁by ▁the ▁suffix ▁" N ", ▁so ▁for ▁the ▁V 8 , ▁ 8 V - 7 1 N . ▁Later ▁versions ▁were ▁available ▁with ▁tur bo charg ers , ▁which ▁dis charg ed ▁directly ▁into ▁the ▁Ro ots ▁blow er ▁int ake ; ▁these ▁have ▁a ▁" T " ▁suffix , ▁and ▁with ▁after co ol ing , ▁a ▁" TA ", ▁so ▁ 8 V - 7 1 T ▁or ▁ 8 V - 7 1 TA . ▁" TT " ▁indicates ▁T ail ored ▁Tor que ▁and ▁" T TA " ▁T ail ored ▁Tor que ▁After co o led . ▁These ▁models ▁are ▁designated ▁for ▁economy ▁( F uel ▁S que e zer ) ▁and ▁constant ▁horse power ▁ratings . ▁