... of a small petrol engine,ann air compressor and a rock drill.During oiperation,rock power is blown away by the compressed ... to work on high mountains,plains,hot and cold area with no power and no water supply and air compressing equipments,and ... pistonφ58 mmStroke of engine piston70 mmRotating speed of engine with load>=2450 rpmDrilling speed>=250 mm/minOil consumption<=0.12 ...