Complex sentence: The first Salmson car proper used a four-cylinder engine designed by Petit with unusual valve gear: a single pushrod actuated both inlet and exhaust valves pushing to open the exhaust and pulling to open the inlet.
Split into simpler sentences: The first Salmson car proper used a four cylinder engine designed by Petit with unusual valve gear. A single pushrod actuated both inlet and exhaust valves pushing to open the exhaust and pulling to open the inlet.