Iím starting my first model steam engine and have decided to use the great plans from Bogstandard. I have decided to make mine a bit bigger and have doubled the size. (20mm bore X 40mm stroke)
I see on the plans that the block port size is ō 1.6mm this would appear to be a critical size as all other dimensions are to the nearest 1/2mm.
I was wondering how this size is calculated? Is there a formula that uses boar and stroke to work this out?
Can I simply double this 1.6mm diameter for my engine? Iíve a funny feeling itís not that simple.