My little engineer

Davis is all about how things work. Often he starts conversations with me that go like this, "Mommy, do you want to hear about how I would make a propellor that spun faster than the rest? First, you would get one propellor that would spin way and another that would spin the other way. You would get two fans from an air conditioner and ...put a gear that meshes perfectly in the one and get two small gears about 1/4 the size of the propellor inside...you hook up any ww2 plane engine...pulley...gear..." I tune out and come back in, but this can go on for a good fifteen minutes.
Do I even need to tell you that he loves legos? And that his amazon wishlist is full of lego gears and motors? That he wants to build his own go-cart?
His dream is to grow up and design solar cars. Let me know if you have any suggestions of great camps or classes or activities that he would enjoy with this theme. He can't get enough of it.