You just made your first game engine. you make a new game. you unlock some new engine part. you don’t want to make a new engine but want that new feature.
this is why i am asking for someone to try to make a mod that lets you update existing engines.
If you can do this you will make my day.
why is everyone calling everyone
(SWAT/ Police speaker)
WAVE JONES WE HAVE AN EMERGENCY CALL
WE HAVE SOMEONE WHO NEEDS A PRO CODER AND A QUICK ONE TOO!!!
IF YOU ARE A PRO CODER THEN GET YO MIND ON DIS!!!
Really I don’t belive it is a good idea, because if you can add parts to a engine you don’t have any reason to create a new engine and expend all the money and time, I think it would be a bit unbalanced.
Maybe we can “update” only allowed parts
Like parts that cost 15 RP in an engine can be upgraded to parts that cost 40 RP
But 40 cant be ported to 60 EXCEPT if the 40 RP part is what the engine started with
What about Parts that are in a group? Like, mono, stereo etc sounds.
parts like new graphics like 2D or 3D would not be allowed but stuff like world design, gameplay, small stuff would.
i think this would be great to be integrated into the expansion pack mod
do you think that this is able to be done?
i would do it but i have 10th grade comming up and i have no c++ experience
graphics i can do
Making something like this wouldn’t be that hard to be honest, since all the engines are stored in the GameManager.company.engines array and the parts in GameManager.company.engines.parts.
So you can create a UI that loads some engine parts, and them simply push them in that array 
im just not great with modding.
last time i modded a game- gta san andreas.
i created the uncontrollable hydra.
The same I thought but the problem would be create the development proces like when you develop a engine, and the UI interface to add parts.
I haven’t dug into things this far yet. I am just getting ready to but I would say, if possible(which I am sure that it is), that you should make it where you could add only like 3 or 4 things to an engine and then after those things are added, you can’t add anything else. Like @Mabb said, if you could just add unlimited things, then there would be no real reason to make another game engine.