RE: Seidel 7-70 radial: Help me decide!
I just got to see a Gnome 50 HP run at Oshkosh, Friday, and I was kind of surprised at the sound. It was loud, but not too loud; you could hear the whirl of the cylinders as much as the exhaust. The exhaust stroke happens at the same point in rotation, so it kind of sounds like a single cylinder with a lot of mechanical noise going on with the odd misfire. It sounded like a single 4 stroke with no muffler at 1/3 throttle with a bunch of mechanical clacks and a house box fan blowing. It does not have the pack of Harleys sound like a radial. It also had the same sound quality of the cars at the same time, too; the sound is of Model T not modern smooth Ferrari. The smell was classic for a modeler; it smelled exactly like a Cox .049 running Cox fuel.