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 powered car in the Brooklands short and long handicap races. The engine displaced , with bore and stroke of 80 x 150 mm. An aluminum crankcase carried two blocks of three cylinders each along each side, with a 60 degree included angle. The cylinders were of iron, with integral cylinder heads with L-shaped combustion chambers. Inlet and exhaust valves were operated by a central camshaft in the V. Valve clearance was set by grinding the relevant parts, the engine lacking any easy means of adjustment. This pointed to Coatalen's ultimate aim of using the new V12 as an aero engine,