How to tell an engine is working
 

Is there any way to clarify wether an engine from a written off car/breakers is fine and working as it should?

Put it in a car and start it, or strip it down completely and check every component.

turn key........ open bonnet......... insert fingers in black coloured belt at front.......if it hurts the engines working

lol

I suppose I was asking for that.

compression check? buy from someone who offers a waranty!