 The latter accepted and thus aimed to participate in the 1919 Indianapolis 500, the first post-war Indianapolis race.Ernest Henry had 101 days (it was in fact necessary to leave Paris no later than April 26, 1919 in order not to miss the boat) to finalize his study and create 4 complete cars for this event.These four Ballot cars, which were designed in the utmost secrecy, naturally resembled pre-war Peugeots, but Ernest Henry, who took the time during the war to improve his design before the war, resumed his sketch hemi engine with four valves per cylinder, inclined at 60°, controlled by a dual overhead cam head, to equip a straight-eight engine capable of 2900 RPM and giving 150 hp for a top speed of nearly .