Hey Chevypower,

I think your wing will be fine if you get a good 3" wrap of fiberglass on the center.

As for your engine mount, I would go with Alex's measurements IF you are sure you are going to use an OS46AX. If you are not sure, then I would SLOW DOWN and wait until you have an engine picked out. It is a lot easier installing blind nuts in a firewall that is not already in a plane.

Your build looks like it's going great, and I know how exciting it is doing your first build, but you really should slow down and enjoy it. My first build was also a Four Star 40, and I built the airframe in a week. I basically put it together like an ARF, and then I stuck in all of the gear after the fact. It is a lot easier to slow down, route all of your control pushrods, etc., before you cover the plane. If you are not 100% sure of your engine, then maybe you should fit one of those adjustable engine mounts that will give you some leeway.

You should also get your throttle cable routed and your fuel tank/lines installed before going much further. It is a lot easier to get everything straight when you have room to work. Same thing with your servo tray, pushrod supports, etc.

Keep up the great work, but make sure you are thinking ahead and enjoy the building process. It's really not a race.