The port on the bottom is actually the upper transfe port. The big one above it is the lower. The cylinder is upside down in the picture. The MS460 saw (and most others) operates via piston ports to the lower transfers. Each side of the piston has 2 windows that aim at the lower when at bdc to help with airflow into the case.I dont own a phantom yet, but in the 2nd & 4th pics are them the transfer ports. What's the smaller port below the big port, or if it's part of the transfer port. What is the reasoning for the pair of ports on both sides. Thanks.