The first zephyr was cut into the piston seal face, then they (theoben)started cutting then into the end of the cylinder to guide air to the transfer port.
Its just a ducting pattern to move the air in the direction of the port.
The first zephyr was cut into the piston seal face, then they (theoben)started cutting then into the end of the cylinder to guide air to the transfer port.
Its just a ducting pattern to move the air in the direction of the port.