Being aeronautical engineering graduate, I have gone through huge literature regarding design of Liquid propellant engines(LPRs). But as I am planning to develop small LPR based on gasoline and oxygen. I want to listen to people here who have already done this. Specifically challenges, their suggestions and any kind of tips. Moreover I have come across this book "How to Design, Build and Test Small Liquid-Fuel Rocket Engines Leroy J. Krzycki – 1967", I'm curious to know about trustworthiness of this book, if anyone has developed a working engine based on this book.

(apology for mistakes, this is my first question).