Production cost savings were achieved by using horizontal valves which, however, did not result in an efficient and powerful combustion chamber. Between 1916 and 1921,[4][page needed] there was a vogue of V12s, during which National (Indianapolis) copied the Packard engine,[citation needed] and Weidely Motors (also of Indianapolis) offered a proprietary engine. Soon after the end of World War I, Lancia offered a 22° V12, Fiat had a 60° model 520 (1921-2), British truck manufacturer Ensign announced a V12 that did not materialize, and in 1926, Daimler (Britain) offered the first of a full range of sleeve valve Double Sixes, 7,136 cc, 3,744 cc, 5,296 cc and 6,511 cc versions remaining available until 1937.[5][page needed] In 1927 more entered the market from Cadillac, Franklin, Hispano-Suiza, Horch, Lagonda, Maybach, Packard, Rolls, Tatra, Voisin, and Walter offering V12 engines.