Okey, I didn’t know as it was not mentioned in your project topic.
Edit: I did some calculations.
S6 R/T on a minarelli scooter:
Bore 47.6mm
Stroke 39.2mm
Swept volume 69.76cc
Rod length 85mm
Exhaust port height 22.5mm
Transfer port height 32.9mm
Squish 0.4mm
Head depth 2.4mm
Deck height 2.8mm
This gives 192.67dg exhaust and 127.55dg transfer port timing, which is pretty good for a high reving 70cc racing cilinder.
S6 R/T on a sprocatti engine:
Bore 47.6mm
Stroke 46.0mm
Swept volume 81.86cc
Rod length 90mm
Exhaust port height 22.5mm
Transfer port height 32.9mm
Squish 0.5mm
Head depth -0.5mm (I guess you milled the top chamber so that piston @ TDC gives deckheight of 0mm)
Deck height 0mm (piston flush with cilinder @ TDC)
This gives 197.11dg exhaust and 143.46dg transfer port timing
The 46mm long stroke really screws up the port timing, especially the transfer port timing. That’s nearly 10dg more than normally is considered “the maximum”. Even if you have a deckheight of -2mm (so piston protrudes 2mm from the cilinder at TDC) you still would get 132dg transfer port duration. How did you want to solve this problem initally?