I-Piston yintshukumo ephindaphindayo kwi-cylinder yomzimba we-injini yemoto. Isakhiwo esisisiseko sepiston sinokuhlulwa sibe phezulu, intloko kunye nesiketi. Umphezulu wepiston yiyona nxalenye ephambili yegumbi lokutsha, kwaye imilo yayo ihambelana nefom yegumbi lokutsha elikhethiweyo. Iinjini zepetroli zihlala zisebenzisa ipiston ephezulu, enenzuzo yendawo encinci yokufunxa ubushushu. Umphezulu wepiston we-injini ye-diesel uhlala unemihadi eyahlukeneyo, imilo yayo ethile, indawo kunye nobukhulu kufuneka bube nokwakheka komxube we-injini ye-diesel kunye neemfuno zokutsha.