By Jason Ballamy 
Part eight - The con rod
M4. C4n

With the piston and crank made the next logical item was something to join the two together - so a bit of 1.5" x 0.375" flat bar was sawn off to form the con rod.

The ends were squared off and the 12" digital callipers bought out to check length.
The hole for the small end bush was then bored.
The other end was drilled for the big end bolts and a centre hole added.
The small end was then reduced to width and a bit more as things looked a bit tight inside the piston if made to drawing.
It was then held by the small end in the 4-jaw and supported with the tailstock at the other and reduced to 3/8" dia which gives this engine its "round rod" nickname.
While the 4-jaw was on the lathe the block of bronze supplied for the big end bearing was faced and then transferred to the mill to square the edges all oversize.
I then did some rough marking out and hacksawed the bearing in two.
The mating faces were then flycut followed by milling the mating slot/spigot and bolt holes drilled.
A couple of dowels were then stuck into the bolt holes to keep things in line while the oil cup spigot and then the sides were turned.
The other few bits are just simple turning jobs, so I won't detail them but these are the parts that make up the piston/rod assembly.
And it all put together.