Lamborghini Miura manual indicating bigger intake valves in English size (but correct size in metric). The intake and exhaust valves in all 4 liter Lamborghini V12 remained the same throughout all models. This intake size misprint carried forward into Espada 400GT and Countach LP 400/LP 400S owners manuals as well. In 1970, Lamborghini development driver Bob Wallace created a test mule that would conform to the FIA's Appendix J racing regulations. The car was appropriately named the Miura Jota (the pronunciation of the letter 'J' in Spanish). Wallace made extensive modifications to the standard Miura chassis and engine. Weight reductions included replacing
V12 engine lowest priced V12 car ever (unadjusted for inflation). 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, there was a vogue of V12s, during which National (Indianapolis) copied the Packard engine, 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