Chainsaw Repair

The combustion chamber question was not from a paper, just my own musing.  The more fuel/air you can trap in the combustion chamber, the more energy is stored in there at ignition.  Delivery Ratio is a way of measuring that by comparing the trapped volume to the displacement. 

So if you can increase the volume available to trap that fuel/air by increasing the combustion chamber volume, do you increase deliver ratio?  You still have to turn whatever is trapped into mechanical power effectively, so DR is not the only factor by far - and a larger combustion chamber (lower compression ratio) may really hurt in doing that.