I was guessing a boiler flue that swirls the heat/gas but no idea what it's on...
Is it engine related?
Yeah Nick, they squeezed the flue across from each other then again at 90 degree's to the first ones. I don't know if there's a third set farther in.
They do three things, you got one with swirls the heat but it also creates more surface to heat and increases boiler capacity.