Been building performance vehicles since the mid 60s. Unless you want to get into gokarts, mini bikes, ride on mowers, u-control air planes.
Spent some were around 40 years as a mechanical designer with a few deversions such as building jets, owned a automotive machine shop, Designed earth drills, worked in civil engineering. Mostly automotive design, Inovations in turbos, 17 years as an engine designer in advance engine design.