Missing engine bits/ not allowed to tweak engines

[Manche]

I have a 1985 engine family that has a 2006 version and often it doesnt let me change the parts, and i found out that is (surely) because it removes the pistons every time i put them in i talk about light forged of course

[Killrob]

Thanks! I was able to reproduce the problem with your description. Will be fixed in the next patch