The invention presents an internal combustion engine with rotating cylinder block able to use liquid and gas fuel. The design allows substantial reduction of weight and vibration in comparison with engines presently in use and will be preferred for use in weight sensitive vehicles. Ability to make part of the cylinders inactive improves fuel efficiency at partial loads.While the engine operation is similar to typical internal combustion engine, the configuration of cylinders and inlet-outlet valves is different. The engine consists of a cylinder block with radially positioned cylinders open to the outside, pistons moving inside cylinders and valve units (or piston units) positioned outside the perimeter the cylinder block and synchronized to open and close inlet-outlet openings located in pistons.