Overhaul Of The Engine Designer

What's going to be the same, how's its going to be different and what it might look like? Thanks to who ever replies :)
A tycoon game made for people who live and breathe cars.
http://phpbb3.automationgame.com/
Daffyflyer wrote:It already does effect piston speed and smoothness, but it will be tweaked so that bigger bore = more valve area, among other things