I have a 29 foot load bearing wall. I am going to leave 4 ft. then tear down a 7ft section and then will have 18 ft still standing. Will the wall still stand or do I need to support it somehow? Thanks for taking the time to help out.

Yes, you will need to support that section roof/ceiling. Without doing the math, a double 2x8 spanning the opening should provide the missing support. These 2x8s will need to be in direct contact with the ceiling joists. Both ends of the 2x8s are to be placed on top of a double 2x4 at each edge of the new opening. Make sure the 2x4s are firmly anchored to the existing wall.

Definitely add a header for the new opening

We all agreed a header is needed. You don't remove the wall and then install the header afterwards either. You need to set jacks in place to lift the load from the wall, cut out your section, install new header and then lower your jacking. Before attempting this section of the project I'd recoomend that you do a bit more homework and search the net for diagrams and pictures of similar projects, just to be safe. When a house falls on your head it leaves a mark.

What is the wall "bearing"? A 2nd story or just an attic area? Also, look under to see where the 2 legs supporting the new header will rest, to be sure you have good bearing for that redistributed weight. Two 2x8's may be enough, but there are charts aplenty, using the answer about what's up above, that'll answer the question. ANd, if an attic is above, you may be able to put an overhead header up there, allowing for beefier lumber and allowing a flush ceiling from room to room.