Originally Posted by
SIUYA
RENURPP.......IGSO540's. At least, that's what was in the Queenair's, the AC680FLs. and the AC680F that I flew what seems like a million years ago in GA.
The AC680E had these - Model: GSO-480-B1A6. I flew the others you mentioned but they weren’t nearly as loud.
The 65-B80 had IGSO-540. There was another model QueenAir that had a flat 8 from memory (need to search the old log books) it wasn’t nearly as loud.