Algodoo

All engines are spring-powered and inspired by Porche engines
First engine is half-stable but can self recover, has got ERC power up system and super powerful. Has got combustion and exhaust simulations
Second engine has a bit smaller power but more stable and have self recovery too, no ERC.
Third engine is like second.
4th engine is super unstable, hasn't got self recovery like third engine or first and second have that (because of power) and has got super small horsepower and Nm.
5th engine is super stable, 2cyl and hasn't got any recovery/help system, small power and rpm
S to activate starters
First engine features:
E to activate ERC
R to release turbo
T to rev turbo (if released)

Use what you need from these engines, but don't forget to give credit