For the conrod a piece of round 2014 had flats milled on either end, then drilled and reamed for big and little ends. it was fixed to a holding block with a couple of top hat bushes and given a pleasing shape.
Followed by turning a couple of bronze bushes that were a lightly pressed in with a drop of 648 for good measure.
Unlike the original I wanted to be able to adjust the ignition timing while the engine was running. The curves on the timing bracket and a small brass knob for the adjuster were again ideal CNC jobs.
The Rocker arm was next up on the list being held at either end on an overlong blank that had the waste material cut off after machining.
The piston was a simple turning job but I did use the CNC to mill out the dog bone shaped internal recess, here it is along with the other small parts.
Another feature I wanted to add was a small cooling fan which was cut from 0.5mm steel steel, a few tabs were included in the code so that it would remain in place while the 2mm cutter worked it's way around the shape, these were simply cut through and the remains filed off to finish.
