in-line four engine with clutch

Simple and working 4 cylinder diesel engine
to be honest i just dont know how to make complex ones with lua etc :) i wanted to make it more beautiful but i dont know how.

Soooo , 1 speed, clutch is on\off like

A - brakes
F - eletric starter , also its " fully opened throttle"
D - release clutch (good thing before starting engine)

So thats my thing, hi everyone and enjoy, cheers!