What should I learn (math/physics/engineering) to realistically design small engines?
Hello,
I’m looking for guidance on what I should be learning if I want to eventually design small engines and build a business around it.
Background:
* I’m a boilermaker (MIG welding / fabrication)
* No formal engineering degree
* Currently unemployed and trying to move toward working for myself long-term
* Based in Australia
* Strong interest in mechanical and aerospace engineering
Goal (long-term):
I’d like to design:
* Small diesel engines (2-stroke and 4-stroke)
* Small gas turbines / jet engines
* Small liquid rocket engines With Turbopump's (at an experimental / educational level)
I’m not trying to jump straight into building these — I want to understand the fundamentals properly first.
Tools / approach:
* I plan to use FOSS tools (LibreCAD, FreeCAD, Blender, Inkscape)
* For manufacturing, I’m considering outsourcing parts to machine shops (e.g. PCBWay or similar)
My main question:
If you were starting from scratch, what exact subjects would you focus on first?
Specifically:
* What level of maths is actually required? (algebra vs calculus vs beyond)
* Which physics topics matter the most for engines?
* What engineering knowledge is essential before attempting real designs?
* In what order should I learn all of this to avoid wasting time?
Constraints:
* Limited budget
* Learning independently (no university for now)
* Wanting a practical, step-by-step path rather than vague advice
I’m looking for a realistic roadmap — even if it’s “you’re underestimating how much you need to learn.”
Appreciate any guidance or reality checks.
If you’ve done similar self-taught pathways, I’d really like to hear how you approached it.
Thanks