It has been stated that since the right cylinder is now the left cylinder that the right intake port is now the exhaust port, and the right exhaust port is now the intake port the timing needs to be different, I have no clue about that, I'm OK with the fact it works and works very well. When flipping there is no difference in the feel between the cylinders. When slowly turning the engine with a tiny ball driver in the glow plug hole the left exhaust valve closes well before bdc and the intake valve closes well after bdc, same as the right side.