the super connie L1649 had Wright turbo compound R3350 engines. These engines had 18 cylinders, two rows of 9 each. ON takeoff the horsepower was 3500 at max throttle setting. They used water injection and dual power recovery turbines (PRT's) The weakes t point on these engines was the PRT. They would fail in the air because of overheating or fatigue. If they had todays metal technology back then they would probably had run a lot better. The PRT was tied into the main crankshaft through a fluid coupling and the other end had the turbine that was driven by the exhust. The prts could recover up to thirty percent more horsepower from the exhust gases from the cylinders. There were three prt's on each engine.
My favorite sexiest aircraft is the DC-3. with wright 1820's on it.( they also came with P&W 1830's buy they don't sound as good) Its like a HD of the air. YOu can tell it by its sound. Single row of 9 cylinders each having over 200 cu in. displacement. They have been flying since the late 30's and are still a working aircraft.
John