As of now I made the cylinders and planned to keep it simple since once its printed its gonna be quite small and any HD details might not come out as good as in the model.
I have also experimented with the following shape of the connecting rod as you can see in the ss.And a minor design which is a donut shaped crankshaft support was made (its not present in the real engine).

The hardest part is yet to come when we have to design a custom crankshaft so that the cylinders move, as of now we could say that about 30% of the engine is done.