A cylinder comprises a cylinder axis, a cylindrical wall, and an exhaust port defined in the wall. At least one central transfer port and at least two side transfer ports are defined in the wall. Each of the at least one central transfer port and each of the at least two side transfer ports has a transfer channel extending therefrom. For each of the at least one central transfer port, an angle about the cylinder axis between a center of the central transfer port and a center of the exhaust port is greater than 135° and less than or equal to 180°. For each of the at least two side transfer ports, an angle about the cylinder axis between a center of the side transfer port and the center of the exhaust port is less than or equal to 135°. Engines and cylinder blocks are also disclosed.