If you want such an engine look up Robert Maddox; he has a youtube channel
https://www.youtube.com/@RobertMaddox and I think sells plans and components so you too can be hated by most of your neighbors for pursuing this hobby late into the night. And by neighbors, I mean anyone in a 2-5 mile radius. The bigger ones go to 900 pounds of thrust. He is hilarious.
Santa has a sleigh, right? And it flies, right? So, aviation content that even Norad says they track. Here's Maddox's pulse jet propelled sleigh flying.