Yes, that is exactly why I was asking. I thought that the end diameter was quite smaller. The way i have it drawn is just like a fusalage, just a housing for everything. There will be a inner tube or duct for the fan. The size and setup of that tube I'm unsure of. I was hopping I could make my own tube that way I could make several and try different ones, or buy one thats made for a jet and build the hull formers around it.