Yeah there have been some interesting engines along the way. during WW2 the lufwaffe had a bomber had engines that were actually 2 12 cylinder engines drivinga single gear box, 4 engines to drive 2 props. I think I saw an engine in a museum that was 3 banks of 8 big failure though. I have a book on the devlopment of different airplanes. There is a picture in there of a B-29 With ligued cooled engines engines built by Westinghouse By the way the cb16had some complex stuff it had a 2 stage supercharger and that engine was used on the DC6 it had a drive for a compressor to pressureise the cabin